TY - INPR A1 - Tannenberg, Robert A1 - Tscheuschner, Georg A1 - Raab, Christopher A1 - Flemig, Sabine A1 - Döring, Sarah A1 - Ponader, Marco A1 - Thurmann, Melinda A1 - Paul, Martin A1 - Weller, Michael G. T1 - Simplified Sample Preparation and Lateral Flow Immunoassay for the Detection of Plant Viruses N2 - Lateral flow immunoassays (LFA) are widely used for decentralized testing, but their application for in-field plant virus diagnostics is often limited by tedious sample preparation. Here, we present a simplified dipstick LFA for the detection and monitoring of cowpea chlorotic mottle virus (CCMV) as a model plant pathogen. The assay employes a monoclonal mouse antibody for capture and a polyclonal rabbit antibody conjugated to 80-nm gold nanoparticles for detection. Conventional sample and conjugate pads are omitted, allowing the test strips to be dipped directly into wells containing plant extract and antibody-gold conjugate. In addition, no plastic casing was necessary, which significantly reduces waste. It was shown that CCMV concentrations as low as 4 μg/L or 400 pg per sample could be reliably detected in 15 minutes. Specificity tests confirmed that other plant viruses, cowpea mosaic virus (CPMV) and tobacco mosaic virus (TMV), did not produce false positive results. Furthermore, we describe a field-compatible sampling procedure using a manual punch and a disposable syringe. This step combines sample grinding, extraction, and conjugate reconstitution within the syringe frit, enabling the analysis of punched leaf discs without laboratory equipment. When applied to CCMV-infected cowpea plants, the assay revealed systemic infection before visual symptoms became apparent. This work demonstrates that simplified LFAs combined with innovative sampling techniques can provide sensitive, specific, and rapid diagnostics for crop monitoring and support early intervention strategies in agriculture. N2 - Lateral Flow Immunoassays (LFA) werden häufig für dezentrale Tests verwendet, aber ihre Anwendung für die Diagnose von Pflanzenviren im Feld wird oft durch die mühsame Probenvorbereitung eingeschränkt. Hier stellen wir einen vereinfachten Dipstick-LFA zum Nachweis und zur Überwachung des Cowpea Chlorotic Mottle Virus (CCMV) als Modellpflanzenpathogen vor. Der Assay verwendet einen monoklonalen Maus-Antikörper zum Einfangen des Virus und einen polyklonalen Kaninchen-Antikörper, der an 80-nm-Goldnanopartikel konjugiert ist, zum Nachweis. Herkömmliche Proben- und Konjugatpads entfallen, sodass die Teststreifen direkt in Vertiefungen getaucht werden können, die Pflanzenextrakt und Antikörper-Gold-Konjugat enthalten. Darüber hinaus war keine Kunststoffhülle erforderlich, was den Abfall erheblich reduziert. Es zeigte sich, dass CCMV-Konzentrationen von nur 4 μg/L oder 400 pg pro Probe innerhalb von 15 Minuten zuverlässig nachgewiesen werden konnten. Spezifitätstests bestätigten, dass andere Pflanzenviren, das Cowpea Mosaic Virus (CPMV) und das Tobacco Mosaic Virus (TMV), keine falsch positiven Ergebnisse lieferten. Darüber hinaus beschreiben wir ein feldtaugliches Probenahmeverfahren unter Verwendung eines manuellen Stanzers und einer Einwegspritze. Dieser Schritt kombiniert das Zerkleinern der Probe, die Extraktion und die Rekonstitution des Konjugats innerhalb der Spritzenfritte und ermöglicht so die Analyse von ausgestanzten Blattscheiben ohne Laborausrüstung. Bei der Anwendung auf CCMV-infizierte Augenbohnenpflanzen zeigte der Test eine systemische Infektion, bevor visuelle Symptome sichtbar wurden. Diese Arbeit zeigt, dass vereinfachte LFAs in Kombination mit innovativen Probenahmetechniken eine sensitive, spezifische und schnelle Diagnostik für die Überwachung von Nutzpflanzen ermöglichen und frühzeitige Interventionsstrategien in der Landwirtschaft unterstützen können. KW - Vigna unguiculata KW - Cowpea KW - Sample preparation KW - Plant pathogen KW - Mobile detection KW - Crop monitoring KW - Plastic waste KW - Lateral flow immunoassay KW - Plant virus KW - Sample pad KW - Conjugate pad PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651731 DO - https://doi.org/10.20944/preprints202512.1492.v1 SP - 1 EP - 14 PB - MDPI CY - Basle, Switzerland AN - OPUS4-65173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Paul, Martin T1 - Real time multichannel biomarker detection using photonic integrated circuits on ultra compact CMOS chips N2 - This work presents the real-time, multichannel detection of the biomolecule Neutravidine using photonic integrated circuits on ultra-compact monolithic CMOS chips. The development focuses on implementing bioassays directly on CMOS platforms, enabling highly integrated and scalable biosensing. The presentation will cover key aspects including microfluidic integration, data analysis, surface functionalization, and chip packaging. T2 - World Biosensor Congress CY - Lisbon, Portugal DA - 18.05.2025 KW - Chips KW - Photonics KW - Biosensor KW - Realtime PY - 2025 AN - OPUS4-63777 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steglich, P. A1 - Mai, C. A1 - Bondarenko, S. A1 - Paul, Martin A1 - Weller, Michael G. A1 - Schrader, S. A1 - Mai, A. T1 - BioPIC - Integration of Biosensors based on Photonic Integrated Circuits by Local-Backside Etching N2 - Silicon photonic sensors are promising candidates for lab-on-a-chip solutions with versatile applications and scalable production prospects using complementary metal-oxide semiconductor (CMOS) fabrication methods. However, the widespread use has been hindered because the sensing area adjoins optical and electrical components making packaging and sensor handling challenging. In this work, a local back-side release of the photonic sensor is employed, enabling a separation of the sensing area from the rest of the chip. This approach allows preserving the compatibility of photonic integrated circuits in the front-end of line and metal interconnects in the back-end of line. T2 - ATTRACT online Conference CY - Online meeting DA - 22.09.2020 KW - Silicon Photonics KW - Photonic Sensor KW - Photonic Integrated Circuits KW - Point-Of-Care-Diagnostics KW - CMOS KW - Microfluidics KW - Lab-on-a-chip KW - Ring resonator PY - 2020 UR - https://attract-eu.com/showroom/project/integration-of-biosensors-based-on-photonic-integrated-circuits-by-local-backside-etching-biopic/ SP - 1 EP - 5 AN - OPUS4-51735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steglich, Patrick A1 - Paul, Martin A1 - Fünning, Tabea A1 - Schumann, Christoph A1 - Mai, Christian A1 - Tannenberg, Robert A1 - Mai, Andreas ED - Cheben, Pavel ED - Čtyroký, Jiří ED - Molina-Fernández, Iñigo T1 - Towards monolithic integration of polymer-based electro-optical devices in silicon photonic integrated circuits using a 250nm SOI technology N2 - Photonic micro-ring resonators (MRR) are widely studied for their high sensitivity across applications like environmental monitoring, healthcare, and chemical analysis. Their evanescent field sensing requires partially unembedded waveguides compatible with CMOS processing. Our approach uses local backside etching with an additional buried oxide (BOX) etch to release waveguides while preserving the back-end of line (BEOL) structure, enabling spatial separation of the sensing area and electronics. The BOX etch critically affects sensor performance, as waveguide surface roughness can alter MRR properties and coupling. We analyzed MRR design variations, comparing wet and dry etching techniques for their effects on optical performance across rib and strip waveguides in quasi-TE and quasi-TM modes. Wafer-level measurements show that backside-released MRR achieve high extinction ratios with slightly reduced quality factors, advancing high-sensitivity photonic sensors. T2 - SPIE Optics + Optoelectronics 2025 CY - Prague, Czech Republic DA - 05.06.2025 KW - Photonic sensors KW - Micro-ring resonator (MRR) KW - Silicon on insulator (SOI) KW - CMOS KW - Local backside etching (LBE) PY - 2025 DO - https://doi.org/10.1117/12.3056280 VL - 13530 SP - 1 EP - 8 PB - SPIE CY - Bellingham, WA , USA AN - OPUS4-63587 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Paul, Martin A1 - Tannenberg, Robert A1 - Tscheuschner, Georg A1 - Ponader, Marco A1 - Weller, Michael G. T1 - Cocaine detection by a laser-induced immunofluorometric biosensor N2 - The trafficking of illegal drugs by criminal networks at borders, harbors, or airports is an increasing issue in public health as these routes ensure the main supply of illegal drugs. The prevention of drug smuggling, including the installation of scanners and other analytical devices to detect ultra-small traces of drugs within a reasonable time frame, remains a challenge. The presented immunosensor is based on a monolithic affinity column with a large excess of immobilized hapten, which traps fluorescently labeled antibodies as long as the analyte cocaine is absent. In the presence of the drug, some binding sites of the antibody will be blocked, which leads to an immediate breakthrough of the labeled protein, detectable by highly sensitive laser-induced fluorescence with the help of a Peltier-cooled complementary metal-oxide-semiconductor (CMOS) camera. Liquid handling is performed with high-precision syringe pumps and microfluidic chip-based mixing devices and flow cells. The biosensor achieved limits of detection of 23 pM (7 ppt) of cocaine with a response time of 90 seconds and a total assay time below 3 minutes. With surface wipe sampling, the biosensor was able to detect 300 pg of cocaine. This immunosensor belongs to the most sensitive and fastest detectors for cocaine and offers near-continuous analyte measurement. KW - Drug search KW - Customs KW - Confiscation KW - Border surveillance KW - Narcotics KW - International drug trade KW - Drug trafficking KW - Illicit drug KW - Immunosensor KW - Antibodies KW - Detection PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529951 DO - https://doi.org/10.20944/preprints202107.0521.v1 SN - 2310-287X N1 - Geburtsname von Ponader, Marco: Wilke, M. - Birth name of Ponader, Marco: Wilke, M. SP - 1 PB - MDPI CY - Basel AN - OPUS4-52995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Ponader, Marco A1 - Röder, Bettina A1 - Paul, Martin A1 - Weller, Michael G. T1 - Sintered glass monoliths as new supports for affinity columns N2 - A novel stationary phase for affinity separations is presented. This material is based on sintered borosilicate glass readily available as semi-finished filter plates with defined porosity and surface area. The material shows fast binding kinetics and excellent long-term stability under real application conditions due to lacking macropores and high mechanical rigidity. The glass surface can be easily modified with standard organosilane chemistry to immobilize selective binders or other molecules used for biointeraction. In this paper, the manufacturing of the columns and their respective column holders by 3D printing is shown in detail. The model system protein A/IgG was chosen as an example to examine the properties of such monolithic columns under realistic application conditions. Several specifications, such as (dynamic) IgG capacity, pressure stability, long-term performance, productivity, non-specific binding, and peak shape, are presented. It could be shown that due to the very high separation speed, 250 mg antibody per hour and column can be collected, which surpasses the productivity of most standard columns of the same size. The total IgG capacity of the shown columns is around 4 mg (5.5 mg/mL), which is sufficient for most tasks in research laboratories. The cycle time of an IgG separation can be less than 1 minute. Due to the glass material's excellent pressure resistance, these columns are compatible with standard HPLC systems. This is usually not the case with standard affinity columns, limited to manual use or application in low-pressure systems. The use of a standard HPLC system also improves the ability for automation, which enables the purification of hundreds of cell supernatants in one day. The sharp peak shape of the elution leads to an enrichment effect, which might increase the concentration of IgG by a factor of 3. The final concentration of IgG can be around 7.5 mg/mL without the need for an additional nanofiltration step. The purity of the IgG was > 95% in one step and nearly 99% with a second polishing run. KW - Affinity Chromatography KW - Glass KW - Purification KW - Antibodies KW - Solid support KW - HPLC KW - FPLC KW - Separation PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529117 DO - https://doi.org/10.20944/preprints202103.0298.v1 SN - 2310-287X N1 - Geburtsname von Ponader, Marco: Wilke, M. - Birth name of Ponader, Marco: Wilke, M. SP - 1 EP - 17 PB - MDPI CY - Basel AN - OPUS4-52911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -