TY - CHAP A1 - Melekhov, Evgeny A1 - Abb, Valerius A1 - Lechner, Alfred A1 - Kammler, Martin ED - Ivanov, Artem ED - Bicker, Marc ED - Patzelt, Peter T1 - Development of a glass-fiber-based spectrometer for the determination of drug residues in groundwater T2 - Tagungsband 2. Symposium Elektronik und Systemintegration ESI 2020 "Intelligente Systeme und ihre Komponenten: Forschung und industrielle Anwendung" N2 - Within the scope of this project, a portable measuring device has been developed which enables a cost-effective analysis of organic substances from ppm to sub-ppm range, such as drug residues in groundwater. The measurement is carried out by means of a surface-enhanced Raman scattering effect (SERS effect) and an exchangeable sensor head. The sensor head used is a nanostructured optical glass fiber glued into a fiber cannula. The tip of the fiber has been processed to act as a SERS cell. The fiber cannula is connected to a freely movable patch cable by using an adapter. Para-thiocresol is used to characterize the SERS cells. Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:860-opus4-2174 SN - 978-3-9818439-4-1 SP - 101 EP - 109 ER - TY - GEN A1 - Melekhov, Evgeny A1 - Abb, Valerius A1 - Weidauer, Tobias A1 - Kammler, Martin A1 - Lechner, Alfred T1 - Tunable Nanopillars as Surface Enhanced Raman Scattering (SERS) Active Structure for Optical Quartz Glass Fiber T2 - SMSI 2021 - Sensors and Instrumentation N2 - In this work, a simple cost effective method to create tunable self-assembled three-dimensional nanostructure array-like nanoantennas on a tip of an optical quartz glass fiber is described. The structures are prepared using lithography-less dry etching. Gold nanoparticles are used as an etching mask using a thin metal-film thermal dewetting technique. The structures are applied as sensor for label-free analysis of organic substances in ppb range, such as drug residues in groundwater. The measurements are carried out by means of a Surface-enhanced Raman scattering (SERS) effect, an exchangeable sensor head, and a portable Raman device. This method allows in situ applications. Parathiocresol is used as a model substance to characterize the SERS cells. For metallization, gold and silver are compared. Reproducible SERS enhancement factors up to 10 7 are evaluated. Y1 - 2021 SN - 978-3-9819376-4-0 U6 - https://doi.org/10.5162/SMSI2021/B8.2 SP - 153 EP - 154 PB - AMA Association for Sensors and Measurement ER - TY - JOUR A1 - Melekhov, Evgeny A1 - Penn, Tatjana A1 - Weidauer, Tobias A1 - Abb, Valerius A1 - Kammler, Martin A1 - Lechner, Alfred T1 - Tunable nanopillar array on a quartz-fiber tip for surface enhanced Raman scattering (SERS) detection JF - tm - Technisches Messen N2 - In this work, a simple two-step method to create tunable self-assembled three-dimensional nanostructure array-like nanoantennas directly on the tip of an optical quartz glass fiber is described. The structures are prepared by using dry etching of the fiber tip. For the etching process, gold nanoparticles fabricated by thermal dewetting technique were used as template. The structures are applied as sensors for label-free analysis of organic substances in ppb range, such as drug residues in liquid solutions. The measurements are carried out by a portable Raman device with an exchangeable sensor head utilizing the SERS-effect. This method allows in situ applications. In order to characterize the SERS cells, para-thiocresol and diclofenac sodium are used as model substances. For optimization of the substrate performance, different thicknesses of the dewetting-layer (6, 9, 12 nm), different etching times for formation of the pillars (6, 8, 10 and 12 min), and different thicknesses of SERS-metallization (25, 50, 75 nm) of gold and silver are compared. In order to show the applicability of the structure on the tip of a fiber, measurements from the upper side and from the underside of the substrate on quartz plates are compared. Reproducible SERS enhancement factors up to 10 7 {10^{7}} were achieved. N2 - In dieser Arbeit wird eine zweistufige Methode beschrieben, um einstellbare selbstorganisierte dreidimensionale SERS-aktive Nanostrukturen in Form von Nanosäulen auf der Spitze einer optischen Quarzglasfaser herzustellen. Die Strukturen werden durch trockenchemisches Ätzen der Faserspitze erzeugt. Für den Ätzprozess werden als Maske Goldnanopartikel verwendet, die mittels Thermal Dewetting hergestellt werden. Der Sensor wird für eine markierungsfreie Analyse von organischen Substanzen, wie bspw. Medikamentenrückstände in wässrigen Lösungen, im ppb-Bereich eingesetzt. Die Messungen werden mit einem tragbaren Raman-Gerät mit einem austauschbaren Sensorkopf durchgeführt. Um die SERS-Zellen zu charakterisieren, werden para-Thiocresol und Diclofenac-Natrium als Modellsubstanzen verwendet. Zur Optimierung der Substratleistung werden unterschiedliche Dicken der Dewettinglayer (6, 9, 12 nm), unterschiedliche Ätzzeiten der Nanosäulen (6, 8, 10 und 12 min) und unterschiedliche Schichtdicken der SERS-Metallisierung (25, 50, 75 nm) von Gold und Silber verglichen. Um die Anwendbarkeit der Struktur an der Spitze einer Faser zu zeigen, werden Messungen von der Oberseite und von der Rückseite des Substrats in Form eines Quarzglasplatten verglichen. Diese Struktur liefert einen reproduzierbaren Verstärkungsfaktor von bis zu 107. T2 - Einstellbare Nanosäulenanordnung auf der Spitze einer Quarzglasfaser für oberflächenverstärkte Raman-Spektroskopie (SERS) Y1 - 2022 U6 - https://doi.org/10.1515/teme-2021-0093 VL - 89 IS - 1 SP - 70 EP - 81 PB - de Gruyter ER - TY - JOUR A1 - Wolfgramm, Alex A1 - Abb, Valerius A1 - Samp, Artur A1 - Samp, Rafal A1 - Hoffmann, Jens Christoph A1 - Müller, Rainer A1 - Kammler, Martin T1 - Structural and functional evolution of HKUST-1 nanoparticles induced by ball milling JF - Next Materials N2 - In this study, the effect of post-synthetic ball milling on the structural and functional properties of as-synthesized nanoparticles of the copper-based metal-organic framework (MOF) HKUST-1 was investigated for the first time. Nanoparticles were synthesized using sodium formate as a capping agent. The crystalline particles were subjected to a controlled ball milling process, which induced significant structural changes. Powder X-ray diffraction (PXRD) revealed a reduction in crystallite size from 91 nm to 21 nm and the introduction of microstrain, partially disrupting the MOF's long-range crystalline order, as evidenced by peak broadening and the diminished intensity of high-angle reflections. Particle morphology pre- and post-milling was further studied with scanning electron microscopy (SEM) imaging, verifying a narrow particle size distribution of ± 22 nm after milling. Fourier-transform infrared spectroscopy (FTIR) indicated protonation of carboxylate groups in the larger pores of the framework, likely due to moisture incorporation during milling. Brunauer-Emmett-Teller (BET) surface area analysis showed a substantial decrease in specific surface area from 521 m²/g to 226 m²/g, suggesting a partial collapse of the porous framework. We discuss the applicability of ball milling as a versatile means of post-synthetic approach to reduce MOF particle sizes, a key element in the preparation of MOF-based thin films using inks or polymers. KW - Ball milling KW - Copper-based metal-organic framework KW - HKUST-1 KW - Nitrogen adsorption Y1 - 2026 U6 - https://doi.org/10.1016/j.nxmate.2025.101544 N1 - Corresponding author der OTH Regensburg: Alex Wolfgramm VL - 10 PB - Elsevier ER -