SiM20 Posters

Sensors in Medicine 2020 22 Low-Cost Microfludic device based on Laser- induced Graphene Electrodes for highly sensitive Electrochemiluminescent Detection of Pathogens Florian Gerstl 1 , Uma Pongkitdachoti 2 , Antje J. Baeumner 1 1 Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, 93053 Regensburg, Germany 2 Department of Chemistry, Faculty of Science, Chulalongkorn University, 10330 Bangkok, Thailand Florian.Gerstl@chemie.uni-regensburg.de Laser-induced graphene (LIG) is an ideal electrode material for low-cost point-of-care (POC) devices. The print-alike fabrication process of LIG electrodes in a laser-engraving system allows for rapid prototyping and near unlimited design flexibility, making them adjustable to all kinds of applications in microfluidic systems. Here, our microfluidic device , optimized towards electrochemiluminescence (ECL) , is employed in a magnetic bead-based hybridization assay . Ru(bpy) 3 2+ encapsulating liposomes are used as a signal enhancement strategy to facilitate the on-chip detection of target DNA sequences derived from C. parvum with a remarkable limit of detection (LOD) down to 133 pmol∙L -1 . PMMA ds-adhesive tape polyimide foil inlet/outlet capture zone WE CE RE • Microfluidic device (4 cm x 2.5 cm) − PMMA plate with inlet/outlet holes − Double-sided adhesive tape (100 µm) with cut-out channel structure − Electrodes on polyimide foil • Electrode layout iteratively optimized (>20 designs tested) • Best trade-off between ECL performance and reproducibility: “T“-shaped working electrode surrounded by 10-times larger counter electrode • Ag/AgCl pseudo-reference electrode made of conductive silver paint • Magnet can be placed under the capture zone to separate bound and unbound liposomes after the assay … Microfluidic chip Abstract