<?xml version="1.0" encoding="utf-8"?>
<export-example>
  <doc>
    <id>50356</id>
    <completedYear/>
    <publishedYear>2020</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>11</pageLast>
    <pageNumber/>
    <edition/>
    <issue>1</issue>
    <volume>21</volume>
    <type>article</type>
    <publisherName>MDPI</publisherName>
    <publisherPlace>Basel, Switzerland</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Length and Energy Dependence of Low-Energy Electron-Induced Strand Breaks in Poly(A) DNA</title>
    <abstract language="eng">The DNA in living cells can be effectively damaged by high-energy radiation, which can lead to cell death. Through the ionization of water molecules, highly reactive secondary species such as low-energy electrons (LEEs) with the most probable energy around 10 eV are generated, which are able to induce DNA strand breaks via dissociative electron attachment. Absolute DNA strand break cross sections of specific DNA sequences can be efficiently determined using DNA origami nanostructures as platforms exposing the target sequences towards LEEs. In this paper, we systematically study the effect of the oligonucleotide length on the strand break cross section at various irradiation energies. The present work focuses on poly-adenine sequences (d(A4), d(A8), d(A12), d(A16), and d(A20)) irradiated with 5.0, 7.0, 8.4, and 10 eV electrons. Independent of the DNA length, the strand break cross section shows a maximum around 7.0 eV electron energy for all investigated oligonucleotides confirming that strand breakage occurs through the initial formation of negative ion resonances. When going from d(A4) to d(A16), the strand break cross section increases with oligonucleotide length, but only at 7.0 and 8.4 eV, i.e., close to the maximum of the negative ion resonance, the increase in the strand break cross section with the length is similar to the increase of an estimated geometrical cross section. For d(A20), a markedly lower DNA strand break cross section is observed for all electron energies, which is tentatively ascribed to a conformational change of the dA20 sequence. The results indicate that, although there is a general length dependence of strand break cross sections, individual nucleotides do not contribute independently of the absolute strand break cross section of the whole DNA strand. The absolute quantification of sequence specific strand breaks will help develop a more accurate molecular level understanding of radiation induced DNA damage, which can then be used for optimized risk estimates in cancer radiation therapy.</abstract>
    <parentTitle language="eng">International Journal of Molecular Sciences</parentTitle>
    <identifier type="doi">10.3390/ijms21010111</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-503563</identifier>
    <enrichment key="date_peer_review">10.02.2020</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Kenny Ebel</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA origami</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA radiation damage</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA strand breaks</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Low-energy electrons</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Sequence dependence</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="institutes" number="">1 Analytische Chemie; Referenzmaterialien</collection>
    <collection role="themenfelder" number="">Chemie und Prozesstechnik</collection>
    <collection role="themenfelder" number="">Chemische Charakterisierung und Spurenanalytik</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <collection role="institutes" number="">1.0 Abteilungsleitung und andere</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/50356/Poly-DNA.pdf</file>
  </doc>
  <doc>
    <id>50357</id>
    <completedYear/>
    <publishedYear>2020</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>628</pageFirst>
    <pageLast>636</pageLast>
    <pageNumber/>
    <edition/>
    <issue>2</issue>
    <volume>36</volume>
    <type>article</type>
    <publisherName>American Chemical Society Publication</publisherName>
    <publisherPlace>Washington</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Streptavidin Homologues for Applications on Solid Surfaces at High Temperatures</title>
    <abstract language="eng">One of the most commonly used bonds between two biomolecules is the bond between biotin and streptavidin (SA) or streptavidin homologues (SAHs). A high dissociation constant and the consequent high-temperature stability even allows for its use in nucleic acid detection under polymerase chain reaction (PCR) conditions. There are a number of SAHs available, and for assay design, it is of great interest to determine as to which SAH will perform the best under assay conditions. Although there are numerous single studies on the characterization of SAHs in solution or selected solid phases, there is no systematic study comparing different SAHs for biomolecule-binding, hybridization, and PCR assays on solid phases. We compared streptavidin, core streptavidin, traptavidin, core traptavidin, neutravidin, and monomeric streptavidin on the surface of microbeads (10–15 μm in diameter) and designed multiplex microbead-based experiments and analyzed simultaneously the binding of biotinylated oligonucleotides and the hybridization of oligonucleotides to complementary capture probes. We also bound comparably large DNA origamis to capture probes on the microbead surface. We used a real-time fluorescence microscopy imaging platform, with which it is possible to subject samples to a programmable time and temperature profile and to record binding processes on the microbead surface depending on the time and temperature. With the exception of core traptavidin and monomeric streptavidin, all other SA/SAHs were suitable for our investigations. We found hybridization efficiencies close to 100% for streptavidin, core streptavidin, traptavidin, and neutravidin. These could all be considered equally suitable for hybridization, PCR applications, and melting point analysis. The SA/SAH–biotin bond was temperature-sensitive when the oligonucleotide was mono-biotinylated, with traptavidin being the most stable followed by streptavidin and neutravidin. Mono-biotinylated oligonucleotides can be used in experiments with temperatures up to 70 °C. When oligonucleotides were bis-biotinylated, all SA/SAH–biotin bonds had similar temperature stability under PCR conditions, even if they comprised a streptavidin variant with slower biotin dissociation and increased mechanostability.</abstract>
    <parentTitle language="eng">Langmuir</parentTitle>
    <identifier type="doi">10.1021/acs.langmuir.9b02339</identifier>
    <enrichment key="date_peer_review">10.02.2020</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>C. Schmidt</author>
    <author>P. Schierack</author>
    <author>U. Gerber</author>
    <author>C. Schröder</author>
    <author>Youngeun Choi</author>
    <author>Ilko Bald</author>
    <author>W. Lehmann</author>
    <author>S. Rödiger</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Biopolymers Probes</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Hybridization</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fluorescence</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Genetics</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="institutes" number="">1 Analytische Chemie; Referenzmaterialien</collection>
    <collection role="themenfelder" number="">Chemie und Prozesstechnik</collection>
    <collection role="themenfelder" number="">Chemische Charakterisierung und Spurenanalytik</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="institutes" number="">1.0 Abteilungsleitung und andere</collection>
  </doc>
  <doc>
    <id>50787</id>
    <completedYear/>
    <publishedYear>2020</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>24712</pageFirst>
    <pageLast>24712</pageLast>
    <pageNumber/>
    <edition/>
    <issue>12</issue>
    <volume>152</volume>
    <type>article</type>
    <publisherName>AIP Publishing</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Kinetics of molecular decomposition under irradiation of gold nanoparticles with nanosecond laser pulses-A 5-Bromouracil case study</title>
    <abstract language="eng">Laser illuminated gold nanoparticles (AuNPs) efficiently absorb light and heat up the surrounding medium, leading to versatile applications ranging from plasmonic catalysis to cancer photothermal therapy. Therefore, an in-depth understanding of the thermal, optical, and electron induced reaction pathways is required. Here, the electrophilic DNA nucleobase analog 5-Bromouracil (BrU) has been used as a model compound to study its decomposition in the vicinity of AuNPs illuminated with intense ns laser pulses under various conditions. The plasmonic response of the AuNPs and the concentration of BrU and resulting photoproducts have been tracked by ultraviolet and visible (UV–Vis) spectroscopy as a function of the irradiation time. A kinetic model has been developed to determine the reaction rates of two parallel fragmentation pathways of BrU, and their dependency on laser fluence and adsorption on the AuNP have been evaluated. In addition, the size and the electric field enhancement of the decomposed AuNPs have been determined by atomic force microscopy and finite domain time difference calculations, respectively. A minor influence of the direct photoreaction and a strong effect of the heating of the AuNPs have been revealed. However, due to the size reduction of the irradiated AuNPs, a trade-off between laser fluence and plasmonic response of the AuNPs has been observed. Hence, the decomposition of the AuNPs might be limiting the achievable temperatures under irradiation with several laser pulses. These findings need to be considered for an efficient design of catalytic plasmonic systems.</abstract>
    <parentTitle language="eng">Journal of Chemical Physics</parentTitle>
    <identifier type="doi">10.1063/1.5137898</identifier>
    <enrichment key="date_peer_review">14.05.2020</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <author>T. S. Marques</author>
    <author>Robin Schürmann</author>
    <author>Kenny Ebel</author>
    <author>C. Heck</author>
    <author>M. Smialek</author>
    <author>Sam Eden</author>
    <author>N. Mason</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Kinetics</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Gold nanoparticles</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>5-Bromouracil</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="institutes" number="">1 Analytische Chemie; Referenzmaterialien</collection>
    <collection role="themenfelder" number="">Chemie und Prozesstechnik</collection>
    <collection role="themenfelder" number="">Chemische Charakterisierung und Spurenanalytik</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="institutes" number="">1.0 Abteilungsleitung und andere</collection>
  </doc>
  <doc>
    <id>35673</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>3001</pageFirst>
    <pageLast>3009</pageLast>
    <pageNumber/>
    <edition/>
    <issue>5</issue>
    <volume>120</volume>
    <type>article</type>
    <publisherName>AMER CHEMICAL SOC</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Decomposition of DNA nucleobases by laser irradiation of gold nanoparticles monitored by surface-enhanced Raman scattering</title>
    <abstract language="eng">Different approaches have been proposed to treat cancer cells using gold nanoparticles (AuNPs) in combination with radiation ranging from infrared lasers to high-energy ion beams. Here we study the decomposition of the DNA/RNA nucleobases thymine (T) and uracil (U) and the well-known radiosensitizer 5-bromouracil (BrU) in close vicinity to AuNPs, which are irradiated with a nanosecond pulsed laser (532 nm) matching the surface plasmon resonance of the&#13;
AuNPs. The induced damage of nucleobases is analyzed by UV−vis Absorption spectroscopy and surface-enhanced Raman scattering (SERS). A clear DNA damage is observed upon laser irradiation. SERS spectra indicate the fragmentation of the aromatic ring system of T and U as the dominant form of damage, whereas with BrU mainly the cleavage of the Br−C bond and formation of Br− ions is observed. This is accompanied by a partial transformation of BrU into U. The observed damage is at least partly ascribed to the intermediate formation of lowenergy electrons from the laser-excited AuNPs and subsequent dissociative electron attachment to T, U, and BrU. These reactions represent basic DNA damage pathways occurring on the one hand in plasmon-assisted cancer therapy and on the other hand in conventional cancer radiation therapy using AuNPs as sensitizing agents.</abstract>
    <parentTitle language="eng">Journal of Physical Chemistry C</parentTitle>
    <identifier type="doi">10.1021/acs.jpcc.5b10564</identifier>
    <enrichment key="date_peer_review">20.04.2016</enrichment>
    <author>Robin Schürmann</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Gold nanoparticles</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>SERS</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Electrons</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA damage</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Gold-Nanopartikel</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Elektronen</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA-Schädigung</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>35876</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>5612</pageFirst>
    <pageLast>5620</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>article</type>
    <publisherName>Royal Society of Chemistry</publisherName>
    <publisherPlace>Cambridge, England</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">DNA origami based Au–Ag-core–shell nanoparticle dimers with single-molecule SERS sensitivity</title>
    <abstract language="eng">DNA origami nanostructures are a versatile tool to arrange metal nanostructures and other chemical entities with nanometer precision. In this way gold nanoparticle dimers with defined distance can be constructed, which can be exploited as novel substrates for surface enhanced Raman scattering (SERS). We have optimized the size, composition and arrangement of Au/Ag nanoparticles to create intense SERS hot spots, with Raman enhancement up to 10^10, which is sufficient to detect single molecules by Raman scattering. This is demonstrated using single dye molecules (TAMRA and Cy3) placed into the center of the nanoparticle dimers. In conjunction with the DNA origami nanostructures novel SERS substrates are created, which can in the future be applied to the SERS analysis of more complex biomolecular targets, whose position and conformation within the SERS hot spot can be precisely controlled.</abstract>
    <parentTitle language="eng">Nanoscale</parentTitle>
    <identifier type="doi">10.1039/C5NR08674D</identifier>
    <identifier type="url">http://pubs.rsc.org/en/content/articlelanding/2016/nr/c5nr08674d#!divAbstract</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-358761</identifier>
    <enrichment key="date_peer_review">28.04.2016</enrichment>
    <licence>Creative Commons - Namensnennung 3.0</licence>
    <author>J. Prinz</author>
    <author>Christian Heck</author>
    <author>L. Ellerik</author>
    <author>V. Merk</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>single molecule spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA origami</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>SERS</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>gold nanoparticles</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>silver nanoparticles</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/35876/2016_NS_Prinz_SERS.pdf</file>
  </doc>
  <doc>
    <id>36256</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>10339</pageFirst>
    <pageLast>10347</pageLast>
    <pageNumber/>
    <edition/>
    <issue>19</issue>
    <volume>8</volume>
    <type>article</type>
    <publisherName>Royal Soc Chemistry</publisherName>
    <publisherPlace>Cambridge, UK</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">An ion-controlled four-color fluorescent telomeric switch on DNA origami structures</title>
    <abstract language="eng">The folding of single-stranded telomeric DNA into guanine (G) quadruplexes is a conformational change that plays a major role in sensing and drug targeting. The telomeric DNA can be placed on DNA origami nanostructures to make the folding process extremely selective for K+ ions even in the presence of high Na+ concentrations. Here, we demonstrate that the K+-selective G-quadruplex formation is reversible when using a cryptand to remove K+ from the G-quadruplex. We present a full characterization of the reversible switching between single-stranded telomeric DNA and G-quadruplex structures using Förster resonance energy transfer (FRET) between the dyes fluorescein (FAM) and cyanine3 (Cy3). When attached to the DNA origami platform, the G-quadruplex switch can be incorporated into more complex photonic networks, which is demonstrated for a three-color and a four-color FRET cascade from FAM over Cy3 and Cy5 to IRDye700 with G-quadruplex-Cy3 acting as a switchable transmitter.</abstract>
    <parentTitle language="eng">Nanoscale</parentTitle>
    <identifier type="doi">10.1039/C6NR00119J</identifier>
    <identifier type="issn">2040-3364</identifier>
    <identifier type="issn">2040-3372</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-362560</identifier>
    <enrichment key="date_peer_review">09.06.2016</enrichment>
    <licence>Creative Commons - Namensnennung 3.0</licence>
    <author>Lydia Olejko</author>
    <author>P. Cywinski</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA origami</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>FRET</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Photonic wire</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>G quadruplex</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/36256/Olejko_et_al - An ion-controlled four-color fluorescent telomeric switch on DNA origami structures.pdf</file>
  </doc>
  <doc>
    <id>35194</id>
    <completedYear/>
    <publishedYear>2015</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>11714</pageFirst>
    <pageLast>11720</pageLast>
    <pageNumber/>
    <edition/>
    <issue>48</issue>
    <volume>13</volume>
    <type>article</type>
    <publisherName>RSC</publisherName>
    <publisherPlace>Cambridge</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">An internal charge transfer-dependent solvent effect in V-shaped azacyanines</title>
    <abstract language="eng">New V-shaped non-centrosymmetric dyes, possessing a strongly electron-deficient azacyanine core, have been synthesized based on a straightforward two-step approach. The key step in this synthesis involves palladium-catalysed cross-coupling of dibromo-N,N'-methylene-2,2'-azapyridinocyanines with arylacetylenes. The resulting strongly polarized π-expanded heterocycles exhibit green to orange fluorescence and they strongly respond to changes in solvent polarity. We demonstrate that differently electron-donating peripheral groups have a significant influence on the internal charge transfer, hence on the solvent effect and fluorescence quantum yield. TD-DFT calculations confirm that, in contrast to the previously studied bis(styryl)azacyanines, the proximity of S1 and T2 states calculated for compounds bearing two 4-N,N-dimethylaminophenylethynyl moieties establishes good conditions for efficient intersystem crossing and is responsible for its low fluorescence quantum yield. Non-linear properties have also been determined for new azacyanines and the results show that depending on peripheral groups, the synthesized dyes exhibit small to large two-photon absorption cross sections reaching 4000 GM.</abstract>
    <parentTitle language="eng">Organic &amp; biomolecular chemistry</parentTitle>
    <identifier type="old">38349</identifier>
    <identifier type="doi">10.1039/c5ob01633a</identifier>
    <identifier type="issn">1477-0520</identifier>
    <identifier type="issn">1477-0539</identifier>
    <enrichment key="date_peer_review">23.12.2015</enrichment>
    <author>M. Tasior</author>
    <author>Ilko Bald</author>
    <author>I. Deperasinska</author>
    <author>P.J. Cywinski</author>
    <author>D.T. Gryko</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fluorescence spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Dyes</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Solvent effect</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>36720</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>Article 28557, 1</pageFirst>
    <pageLast>9</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>6</volume>
    <type>article</type>
    <publisherName>Nature Publishing Group</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">White carbon: Fluorescent carbon nanoparticles with tunable quantum yield in a reproducible green synthesis</title>
    <abstract language="eng">In this study, a new reliable, economic, and environmentally-friendly one-step synthesis is established to obtain carbon nanodots (CNDs) with well-defined and reproducible photoluminescence (PL) properties via the microwave-assisted hydrothermal treatment of starch and Tris-acetate-EDTA (TAE) buffer as carbon sources. Three kinds of CNDs are prepared using different sets of above mentioned starting materials. The as-synthesized CNDs: C-CND (starch only), N-CND 1 (starch in TAE) and N-CND 2 (TAE only) exhibit highly homogenous PL and are ready to use without need for further purification.&#13;
The CNDs are stable over a long period of time (&gt;1 year) either in solution or as freeze-dried powder. Depending on starting material, CNDs with PL quantum yield (PLQY) ranging from less than 1% up to 28% are obtained. The influence of the precursor concentration, reaction time and type of additives on the optical properties (UV-Vis absorption, PL emission spectrum and PLQY) is carefully investigated, providing insight into the chemical processes that occur during CND formation. Remarkably, upon freeze-drying the initially brown CND-solution turns into a non-fluorescent white/slightly Brown powder which recovers PL in aqueous solution and can potentially be applied as fluorescent marker in bio-imaging, as a reduction agent or as a photocatalyst.</abstract>
    <parentTitle language="eng">Scientific Reports</parentTitle>
    <identifier type="doi">10.1038/srep28557</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-367204</identifier>
    <enrichment key="date_peer_review">18.07.2016</enrichment>
    <licence>Creative Commons - Namensnennung 3.0</licence>
    <author>T. Meiling</author>
    <author>P. Cywinski</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Carbon dots</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Quantum yield</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fluorescence</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Nanoparticles</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/36720/Bald_et_al - White carbon - Fluorescent carbon nanoparticles with tunable quantum yield in a reproducible green synthesis.pdf</file>
  </doc>
  <doc>
    <id>38369</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>5458</pageFirst>
    <pageLast>5467</pageLast>
    <pageNumber/>
    <edition/>
    <issue>39</issue>
    <volume>12</volume>
    <type>article</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Hybrid structures for surface-enhanced Raman scattering: DNA origami/gold nanoparticle dimer/graphene</title>
    <abstract language="eng">A combination of three innovative materials within one hybrid structure to explore the synergistic interaction of their individual properties is presented. The unique electronic, mechanical, and thermal properties of graphene are combined with the plasmonic properties of gold nanoparticle (AuNP) dimers, which are assembled using DNA origami nanostructures. This novel hybrid structure is characterized by means of correlated atomic force microscopy and surface-enhanced Raman scattering (SERS). It is demonstrated that strong interactions between graphene and AuNPs result in superior SERS performance of the hybrid structure compared to their individual components. This is particularly evident in efficient fluorescence quenching, reduced background, and a decrease of the photobleaching rate up to one order of magnitude. The versatility of DNA origami structures to serve as interface for complex and precise arrangements of nanoparticles and other functional entities provides the basis to further exploit the potential of the here presented DNA origami–AuNP dimer–graphene hybrid structures.</abstract>
    <parentTitle language="eng">Small</parentTitle>
    <identifier type="doi">10.1002/smll.201601908</identifier>
    <identifier type="url">http://onlinelibrary.wiley.com/doi/10.1002/smll.201601908/full</identifier>
    <identifier type="issn">1613-6810</identifier>
    <identifier type="issn">1613-6829</identifier>
    <enrichment key="date_peer_review">05.01.2017</enrichment>
    <author>J. Prinz</author>
    <author>A. Matkovic</author>
    <author>J. Pesic</author>
    <author>R. Gajic</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA origami</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Gold nanoparticles</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Graphene</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Surface-enhanced Raman scattering</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>44702</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>4680</pageFirst>
    <pageLast>4688</pageLast>
    <pageNumber/>
    <edition/>
    <issue>18</issue>
    <volume>24</volume>
    <type>article</type>
    <publisherName>Wiley</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Low‐energy electron‐induced strand breaks in telomere‐derived DNA sequences—influence of DNA sequence and topology</title>
    <abstract language="eng">During cancer radiation therapy high‐energy radiation is used to reduce tumour tissue. The irradiation produces a shower of secondary low‐energy (&lt;20 eV) electrons, which are able to damage DNA very efficiently by dissociative electron attachment. Recently, it was suggested that low‐energy electron‐induced DNA strand breaks strongly depend on the specific DNA sequence with a high sensitivity of G‐rich sequences. Here, we use DNA origami platforms to expose G‐rich telomere sequences to low‐energy (8.8 eV) electrons to determine absolute cross sections for strand breakage and to study the influence of sequence modifications and topology of telomeric DNA on the strand breakage. We find that the telomeric DNA 5′‐(TTA GGG)2 is more sensitive to low‐energy electrons than an intermixed sequence 5′‐(TGT GTG A)2 confirming the unique electronic properties resulting from G‐stacking. With increasing length of the oligonucleotide (i.e., going from 5′‐(GGG ATT)2 to 5′‐(GGG ATT)4), both the variety of topology and the electron‐induced strand break cross sections increase. Addition of K+ ions decreases the strand break cross section for all sequences that are able to fold G‐quadruplexes or G‐intermediates, whereas the strand break cross section for the intermixed sequence remains unchanged. These results indicate that telomeric DNA is rather sensitive towards low‐energy electron‐induced strand breakage suggesting significant telomere shortening that can also occur during cancer radiation therapy.</abstract>
    <parentTitle language="eng">Chemistry - European Journal</parentTitle>
    <identifier type="doi">10.1002/chem.201705889</identifier>
    <identifier type="issn">1521-3765</identifier>
    <identifier type="issn">0947-6539</identifier>
    <enrichment key="date_peer_review">17.04.2018</enrichment>
    <author>Jenny Rackwitz</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA radiation damage</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Telomere</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA origami</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Electron</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>44703</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>5578</pageFirst>
    <pageLast>5585</pageLast>
    <pageNumber/>
    <edition/>
    <issue>8</issue>
    <volume>20</volume>
    <type>article</type>
    <publisherName>Royal Society of Chemistry</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Hydroperoxyl radical and formic acid formation from common DNA stabilizers upon low energy electron attachment</title>
    <abstract language="eng">2-Amino-2-(hydroxymethyl)-1,3-propanediol (TRIS) and ethylene-diaminetetraacetic acid (EDTA) are key components of biological buffers and are frequently used as DNA stabilizers in irradiation studies. Such surface or liquid phase studies are done with the aim to understand the fundamental mechanisms of DNA radiation damage and to improve cancer radiotherapy. When ionizing radiation is used, abundant secondary electrons are formed during the irradiation process, which are able to attach to the molecular compounds present on the surface. In the present study we experimentally investigate low energy electron attachment to TRIS and methyliminodiacetic acid (MIDA), an analogue of EDTA, supported by quantum chemical calculations. The most prominent dissociation channel for TRIS is through hydroperoxyl radical formation, whereas the dissociation of MIDA results in the formation of formic and acetic acid. These compounds are well-known to cause DNA modifications, like strand breaks. The present results indicate that buffer compounds may not have an exclusive protecting effect on DNA as suggested previously.</abstract>
    <parentTitle language="eng">Physical chemistry chemical physics</parentTitle>
    <identifier type="doi">10.1039/c7cp07697e</identifier>
    <identifier type="url">http://pubs.rsc.org/en/content/articlepdf/2018/cp/c7cp07697e</identifier>
    <enrichment key="date_peer_review">18.04.2018</enrichment>
    <author>A. Ribar</author>
    <author>S. E. Huber</author>
    <author>M. A. Smiałek</author>
    <author>K. Tanzer</author>
    <author>M. Neustetter</author>
    <author>Robin Schürmann</author>
    <author>Ilko Bald</author>
    <author>S. Denifl</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DEA</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Low energy electrons</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Mass spectrometry</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>46679</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>24137</pageFirst>
    <pageLast>24142</pageLast>
    <pageNumber/>
    <edition/>
    <issue>42</issue>
    <volume>122</volume>
    <type>article</type>
    <publisherName>ACS</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Selective synthesis of ethylene and acetylene from dimethyl sulfide cold films controlled by slow electrons</title>
    <abstract language="eng">One of the major challenges in chemical synthesis is to trigger and control a specific reaction route leading to a specific final product, while side products are avoided. Methodologies based on resonant processes at the molecular level, for example, photochemistry, offer the possibility of inducing selective reactions. Electrons at energies below the molecular ionization potential (&lt;10 eV) are known to dissociate molecules via resonant processes with higher cross sections and specificity than photons. Here we show that even subexcitation electrons with energies as low as 1 eV produce ethylene and acetylene from dimethyl sulfide in competing reactions. However, the production of ethylene can specifically be targeted by controlling the energy of electrons (∼3 to 4 eV). Finally, pure ethylene is selectively desorbed by heating the substrate from 90 to 105 K. Beyond the synthesis of these versatile hydrocarbons for various industrial applications from a biogenic sulfur compound, our findings demonstrate the feasibility of electron-induced selective chemistry applicable on the nanoscale.</abstract>
    <parentTitle language="eng">Journal of Physical Chemistry C</parentTitle>
    <identifier type="doi">10.1021/acs.jpcc.8b07377</identifier>
    <identifier type="issn">1932-7447</identifier>
    <enrichment key="date_peer_review">21.11.2018</enrichment>
    <author>H. Abdoul-Carime</author>
    <author>Ilko Bald</author>
    <author>E. Illenberger</author>
    <author>J. Kopyra</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Low-energy electrons</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Dissociative electron attachment</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Green chemistry</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>45070</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>115</pageFirst>
    <pageLast>121</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>146</volume>
    <type>article</type>
    <publisherName>Elsevier B.V.</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Challenges in the quantification of nutrients in soils using laser-induced breakdown spectroscopy – A case study with calcium</title>
    <abstract language="eng">The quantification of the elemental content in soils with laser-induced breakdown spectroscopy (LIBS) is challenging because of matrix effects strongly influencing the plasma formation and LIBS signal. Furthermore, soil heterogeneity at the micrometre scale can affect the accuracy of analytical results. In this paper, the impact of univariate and multivariate data evaluation approaches on the quantification of nutrients in soil is discussed. Exemplarily, results for calcium are shown, which reflect trends also observed for other elements like magnesium, silicon and iron. For the calibration models, 16 certified reference soils were used. With univariate and multivariate approaches, the calcium mass fractions in 60 soils from different testing grounds in Germany were calculated. The latter approach consisted of a principal component analysis (PCA) of adequately pre-treated data for classification and identification of outliers, followed by partial least squares regression (PLSR) for quantification. For validation, the soils were also characterised with inductively coupled plasma optical emission spectroscopy (ICP OES) and X-ray fluorescence (XRF) analysis. Deviations between the LIBS quantification results and the reference analytical results are discussed.</abstract>
    <parentTitle language="eng">Spectrochimica Acta Part B</parentTitle>
    <identifier type="doi">10.1016/j.sab.2018.05.003</identifier>
    <enrichment key="date_peer_review">06.08.2018</enrichment>
    <author>Madlen Rühlmann</author>
    <author>Dominique Büchele</author>
    <author>Markus Ostermann</author>
    <author>Ilko Bald</author>
    <author>Thomas Schmid</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Laser-induced breakdown spectroscopy (LIBS)</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Soil</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Multivariate data analysis</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Principal component analysis (PCA)</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Partial least squares regression (PLSR)</value>
    </subject>
    <collection role="ddc" number="628">Sanitär- und Kommunaltechnik; Umwelttechnik</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>45426</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>10217</pageFirst>
    <pageLast>10230</pageLast>
    <pageNumber/>
    <edition/>
    <issue>18</issue>
    <volume>122</volume>
    <type>article</type>
    <publisherName>American Chemical Society</publisherName>
    <publisherPlace>Washington, DC</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Photophysics and chemistry of nitrogen-doped carbon nanodots with high photoluminescence quantum yield</title>
    <abstract language="eng">Fluorescent carbon nanodots (CNDs) are very promising nanomaterials for a broad range of applications because of their high photostability, presumed selective luminescence, and low cost at which they can be produced. In this respect, CNDs are superior to well-established semiconductor quantum dots and organic dyes. However, reported synthesis protocols for CNDs typically lead to low photoluminescence quantum yield (PLQY) and low reproducibility, resulting in a poor understanding of the CND chemistry and photophysics. Here, we report a one-step synthesis of nitrogen-doped carbon nanodots (N-CNDs) from various carboxylic acids, Tris, and ethylenediaminetetraacetic acid resulting in high PLQY of up to 90%. The reaction conditions in terms of starting materials, temperature, and reaction time are carefully optimized and their influence on the photophysical properties is characterized. We find that citric acid-derived N-CNDs can result in a very high PLQY of 90%, but they do not Show selective luminescence. By contrast, acetic acid-derived N-CNDs show selective luminescence but a PLQY of 50%. The chemical&#13;
composition of the surface and core of these two selected N-CND types is characterized among others by high-Resolution synchrotron X-ray photoelectron spectroscopy using single isolated N-CND clusters. The results indicate that photoexcitation occurs in the N-CND core, whereas the emission properties are determined by the N-CND surface groups.</abstract>
    <parentTitle language="eng">The Journal of Physical Chemistry C</parentTitle>
    <identifier type="doi">10.1021/acs.jpcc.8b00748</identifier>
    <identifier type="issn">1932-7447</identifier>
    <enrichment key="date_peer_review">10.07.2018</enrichment>
    <author>T. T. Meiling</author>
    <author>Robin Schürmann</author>
    <author>Stefanie Vogel</author>
    <author>Kenny Ebel</author>
    <author>C. Nicolas</author>
    <author>A. R. Milosavljević</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Carbon nanodots</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fluorescence</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Synchrotron XPS</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>45742</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>10271</pageFirst>
    <pageLast>10279</pageLast>
    <pageNumber/>
    <edition/>
    <issue>41</issue>
    <volume>24</volume>
    <type>article</type>
    <publisherName>WILEY</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">The physico-chemical basis of DNA radiosensitization: Implications for cancer radiation therapy</title>
    <abstract language="eng">High-energy radiation is used in combination with radiosensitizing therapeutics to treat cancer. The most common radiosensitizers are halogenatednucleo-sides and cisplatin derivatives, and recently also metal nanoparticles have been suggested as potentialradiosensitizing agents. The radiosensitizingaction of these compounds can at least partly be ascribed to an enhancedreactivity towards secondary low-energy electrons generated along the radiation track of the high-energyprimary radiation, or to an additional emission of secondary reactive electrons close to the tumor tissue. This is referred to as physico-chem ical radiosensitization. In this Conceptarticle we presentcurrent experimental methodsused to study fundamentalprocesses of physico-chemical radiosensitization and discuss the most relevant classes of radiosensitizers. Open questions in the current discussions are identified and future directions outlined, which can lead to optimized treatment protocols or even novel therapeuticconcepts.</abstract>
    <parentTitle language="eng">Chemistry - A European Journal</parentTitle>
    <identifier type="doi">10.1002/chem.201800804</identifier>
    <identifier type="issn">1521-3765</identifier>
    <identifier type="issn">0947-6539</identifier>
    <enrichment key="date_peer_review">21.08.2018</enrichment>
    <author>Robin Schürmann</author>
    <author>Stefanie Vogel</author>
    <author>Kenny Ebel</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Radiosensitization</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Radiation damage</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Low energy electrons</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>45743</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>7444</pageFirst>
    <pageLast>7447</pageLast>
    <pageNumber/>
    <edition/>
    <issue>25</issue>
    <volume>57</volume>
    <type>article</type>
    <publisherName>WILEY</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Placement of single proteins within the SERS hot spots of self-assembled silver nanolenses</title>
    <abstract language="eng">This study demonstrates the bottom-up synthesis of&#13;
silver nanolenses.Arobust coating protocol enabled the&#13;
functionalization of differently sized silver nanoparticles with&#13;
DNAsingle strands of orthogonal sequence.Coated particles&#13;
10 nm, 20 nm, and 60 nm in diameter were self-assembled by&#13;
DNAorigami scaffolds to form silver nanolenses.Single&#13;
molecules of the protein streptavidin were selectively placed in&#13;
the gap of highest electric field enhancement. Streptavidin&#13;
labelled with alkyne groups served as model analyte in surface-&#13;
enhanced Raman scattering (SERS) experiments.Bycorre-&#13;
lated Raman mapping and atomic force microscopy, SERS&#13;
signals of the alkyne labels of asingle streptavidin molecule,&#13;
from asingle silver nanolens,were detected. The discrete,self-&#13;
similar aggregates of solid silver nanoparticles are promising&#13;
for plasmonic applications.</abstract>
    <parentTitle language="eng">Angewandte Chemie International Edition</parentTitle>
    <identifier type="doi">10.1002/anie.201801748</identifier>
    <identifier type="issn">1433-7851</identifier>
    <enrichment key="date_peer_review">21.08.2018</enrichment>
    <author>Christian Heck</author>
    <author>Y. Kanehira</author>
    <author>Janina Kneipp</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA origami</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Surface enhanced Raman scattering</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Protein</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Single molecule</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Nanotechnology</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>32196</id>
    <completedYear/>
    <publishedYear>2014</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>6</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>53</volume>
    <type>article</type>
    <publisherName>Wiley-VCH</publisherName>
    <publisherPlace>Weinheim</publisherPlace>
    <creatingCorporation>Gesellschaft Deutscher Chemiker</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Ion-selective formation of a guanine quadruplex on DNA origami structures</title>
    <abstract language="eng">DNA origami nanostructures are a versatile tool that can be used to arrange functionalities with high local control to study molecular processes at a single-molecule level. Here, we demonstrate that DNA origami substrates can be used to suppress the formation of specific guanine (G) quadruplex structures from telomeric DNA. The folding of telomeres into G-quadruplex structures in the presence of monovalent cations (e.g. Na+ and K+) is currently used for the detection of K+ ions, however, with insufficient selectivity towards Na+. By means of FRET between two suitable dyes attached to the 3'- and 5'-ends of telomeric DNA we demonstrate that the formation of G-quadruplexes on DNA origami templates in the presence of sodium ions is suppressed due to steric hindrance. Hence, telomeric DNA attached to DNA origami structures represents a highly sensitive and selective detection tool for potassium ions even in the presence of high concentrations of sodium ions.</abstract>
    <parentTitle language="eng">Angewandte Chemie / International Edition</parentTitle>
    <identifier type="old">35261</identifier>
    <identifier type="doi">10.1002/anie.201409278</identifier>
    <identifier type="url">http://onlinelibrary.wiley.com/doi/10.1002/anie.201409278/full</identifier>
    <identifier type="issn">1433-7851</identifier>
    <identifier type="issn">1521-3773</identifier>
    <identifier type="issn">0570-0833</identifier>
    <enrichment key="date_peer_review">11.12.2014</enrichment>
    <author>L. Olejko</author>
    <author>P.J. Cywinski</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA nanotechnology</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>FRET</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>G-quadruplexes</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Nanostructures</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Self-assembly</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA origami</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fluorescence spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Sensing</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>31155</id>
    <completedYear/>
    <publishedYear>2014</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>146, 1</pageFirst>
    <pageLast>7</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>68</volume>
    <type>article</type>
    <publisherName>Springer</publisherName>
    <publisherPlace>Berlin</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Influence of metal ion complexation on the metastable fragmentation of DNA hexamers</title>
    <abstract language="eng">Here, we study the metastable decay of 5'-d(TTGCTT) in the presence of 0–6 alkaline metal ions (Li+, Na+, K+, Rb+) and 0–3 alkaline earth metal ions (Mg2+ and Ca2+), which replace the corresponding number of protons in the oligonucleotide. We find that all ions studied here stabilize the oligonucleotide with respect to simple 3'-C–O backbone cleavage, but at the same time these metal ions promote a central oligonucleotide deletion accompanied by a concomitant recombination of the terminal d(TT) groups. We find that the quenching of the 3'-C–O backbone cleavage is not ion specific, since it is due to the removal of the phosphate protons upon replacement with the respective metal ions. The central nucleotide deletion competes with the 3'-C–O backbone cleavage channels and is thus promoted through the replacement of the exchangeable protons against metal ions. However, with increasing positive charge density of the metal ions the yield of the central nucleotide deletion further increases. We attribute this effect to the necessity of sufficient proximity of the terminal d(TT) group to allow for their recombination on this reaction path. Hence, the formation of a reactive conformer is mediated by the metal ions.</abstract>
    <parentTitle language="eng">The European physical journal D</parentTitle>
    <identifier type="old">34149</identifier>
    <identifier type="doi">10.1140/epjd/e2014-40838-7</identifier>
    <identifier type="issn">1434-6060</identifier>
    <enrichment key="date_peer_review">13.08.2014</enrichment>
    <author>A. Piecarczyk</author>
    <author>Ilko Bald</author>
    <author>H.D. Flossadóttir</author>
    <author>B. Ómarsson</author>
    <author>A. Lafosse</author>
    <author>O. Ingólfsson</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA oligonucleotides</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Matrix-assisted laser desorption/ionization</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Metastable decay</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Mass spectrometry</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>29907</id>
    <completedYear/>
    <publishedYear>2013</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>4140</pageFirst>
    <pageLast>4145</pageLast>
    <pageNumber/>
    <edition/>
    <issue>23</issue>
    <volume>4</volume>
    <type>article</type>
    <publisherName>ACS</publisherName>
    <publisherPlace>Washington, DC</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">DNA origami substrates for highly sensitive surface-enhanced Raman scattering</title>
    <abstract language="eng">DNA nanotechnology holds great promise for the fabrication of novel plasmonic nanostructures and the potential to carry out single-molecule measurements using optical spectroscopy. Here, we demonstrate for the first time that DNA origami nanostructures can be exploited as substrates for surface-enhanced Raman scattering (SERS). Gold nanoparticles (AuNPs) have been arranged into dimers to create intense Raman scattering hot spots in the interparticle gaps. AuNPs (15 nm) covered with TAMRA-modified DNA have been placed at a nominal distance of 25 nm to demonstrate the formation of Raman hot spots. To control the plasmonic coupling between the nanoparticles and thus the field enhancement in the hot spot, the size of AuNPs has been varied from 5 to 28 nm by electroless Au deposition. By the precise positioning of a specific number of TAMRA molecules in these hot spots, SERS with the highest sensitivity down to the few-molecule level is obtained.</abstract>
    <parentTitle language="eng">The journal of physical chemistry letters</parentTitle>
    <identifier type="old">32844</identifier>
    <identifier type="doi">10.1021/jz402076b</identifier>
    <identifier type="issn">1948-7185</identifier>
    <enrichment key="date_peer_review">09.01.2014</enrichment>
    <author>J. Prinz</author>
    <author>B. Schreiber</author>
    <author>L. Olejko</author>
    <author>J. Oertel</author>
    <author>J. Rackwitz</author>
    <author>A. Keller</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DANN Origami</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Surface-enhanced Raman scattering</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Nanoparticles</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>TAMRA</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>40070</id>
    <completedYear/>
    <publishedYear>2017</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>10796</pageFirst>
    <pageLast>10803</pageLast>
    <pageNumber/>
    <edition/>
    <issue>17</issue>
    <volume>19</volume>
    <type>article</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Effect of adsorption kinetics on dissociation of DNA-nucleobases on gold nanoparticles under pulsed laser illumination</title>
    <abstract language="eng">Photothermal therapy is a novel approach to destroy cancer cells by an increase of temperature due to laser illumination of gold nanoparticles (GNPs) that are incorporated into the cells. Here, we study the decomposition of DNA nucleobases via irradiation of gold nanoparticles with ns-laser pulses. The kinetics of the adsorption and decomposition process is described by a theoretical model based on the Langmuir assumptions and correlated with experimentally determined reaction rates revealing a strong influence of the nucleobase specific adsorption. Beside the four nucleobases, their brominated analogs, which are potential radiosensitizers in cancer therapy, are also investigated and show a significant modification of the decomposition rates. The fastest decomposition rates are observed for adenine, 8-bromoadenine, 8-bromoguanine and 5-bromocytosine. These results are in good agreement with the relative adsorption rates that are determined from the aggregation kinetics of the GNPs taking the effect of an inhomogeneous surface into account. For adenine and its brominated analog, the decomposition products are further analyzed by surface enhanced Raman scattering (SERS) indicating a strong fragmentation of the molecules into their smallest subunits.</abstract>
    <parentTitle language="eng">Physical Chemistry Chemical Physics</parentTitle>
    <identifier type="doi">10.1039/c6cp08433h</identifier>
    <identifier type="issn">1463-9076</identifier>
    <identifier type="issn">1463-9084</identifier>
    <enrichment key="date_peer_review">02.06.2017</enrichment>
    <author>Robin Schürmann</author>
    <author>Ilko Bald</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Gold nanoparticle</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DNA damage</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Kinetics</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Pulsed Laser</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Physical Chemistry</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
</export-example>
