TY - JOUR 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 JF - Biosensors N2 - Lateral flow immunoassays (LFAs) are widely used for on-site testing; however, their use for the rapid detection of plant viruses in the field is often limited by inconvenient sample preparation. Here, we present a new sampling method and a simplified dipstick LFA format for the detection and monitoring of cowpea chlorotic mottle virus (CCMV) as a model plant pathogen. The assay employs a monoclonal mouse antibody for capture and a poly-clonal 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. No plastic casing was required, which could lead to a reduction in waste. It was shown that CCMV concentrations as low as 3.5 μg/L or 350 pg per sample could be reliably detected in 15 min. Specificity tests confirmed that other plant viruses, cowpea mosaic virus (CPMV) and tobacco mosaic virus (TMV), did not produce false-positive results. In addition, we describe a new method for on-site sampling using a manual punch and a syringe equipped with a frit. This step combines grinding the sample, extraction, filtration, and reconstitution and mixing of the antibody-gold conjugate, enabling the analysis of punched leaf disks 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. KW - LFA format KW - Vigna unguiculata KW - cowpea chlorotic mottle virus KW - crop monitoring KW - lateral flow immunoassay KW - plant virus KW - sample preparation KW - waste reduction Y1 - 2026 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-21294 VL - 16 IS - 2 PB - MDPI ER - TY - CHAP A1 - Fünning, Tabea A1 - Peczek, Anna A1 - Kroh, Aleksandra A1 - Mai, Christian A1 - Paul, Martin A1 - Thomsen, Florian A1 - Tannenberg, Robert A1 - Schumann, Christoph A1 - Weller, Michael G. A1 - Mai, Andreas A1 - Steglich, Patrick ED - Baldini, Francesco ED - Homola, Jiri ED - Lieberman, Robert A. T1 - Optimization of local backside released micro-ring resonators for sensing applications using silicon photonic integrated circuits in a SOI technology T2 - Proceedings of SPIE : Optical Sensors 2025 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. KW - photonic sensor KW - micro-ring resonator (MRR) KW - silicon-on-insulator (SOI) KW - local backside etching (LBE) Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-20449 VL - 13527 PB - SPIE ER - TY - CHAP A1 - Tannenberg, Robert A1 - Paul, Martin A1 - Fünning, Tabea A1 - Schumann, Christoph A1 - Weller, Michael G. A1 - Steglich, Patrick ED - Baldini, Francesco ED - Homola, Jiri ED - Lieberman, Robert A. T1 - Multichannel real-time detection of biomarkers with highly miniaturized photonic microchips T2 - Proceedings of SPIE : Optical Sensors 2025 N2 - The development of novel photonic integrated microchips (PIC) is a promising approach to allow for the convenient detection of key biomarkers in complex matrices through multichannel real-time analysis in a highly compact package. This study reports the successful development and application of a backside released CMOS chip designed for the multichannel real-time detection of biomarkers. Operating at the C-band at approx. 1550 nm, the microchip features three dedicated detection sensors in addition to a reference sensor, enabling simultaneous analysis of multiple biomarkers. The compact and highly miniaturized design of this microchip, with a footprint of just 1 mm², positions it as promising candidate for point-of-care diagnostics and personalized medicine applications. This technology opens a path to transform biomarker detection across various medical fields, offering rapid, reliable, and cost-effective diagnostic solutions. In conclusion, the presented multichannel photonic microchips signify a substantial leap forward in real-time biomarker detection, providing a highly capable platform for future research and clinical applications. KW - photonic biosensor KW - silicon photonics KW - photonic integrated circuit KW - immunosensor KW - biochemical sensor KW - optical biosensor KW - surface functionalization Y1 - 2025 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-20456 VL - 13527 PB - SPIE ER -