The detection of biomarkers at very low concentration and low cost is increasinglyimportant for clinical diagnosis. Moreover, monitoring affinities for receptor-antagonist interactions by time-resolved measurements is crucial for drug discovery and development. Biosensors based on ion-sensitive field-eff ect transistors (BioFETs) are promising candidates for being integrated into CMOS structures and cost-e ffective production. The detection of DNA and proteins with silicon nanowires has been successfully demonstrated using high affinity systems such as the biotin-streptavidin interaction. Here, we show the time-resolved label-free detection of the interaction of the bacterial FimH lectin with an immobilized mannose ligand on gold-coated silicon nanoribbon BioFETs. By comparing our results with a commercial state of the art surface plasmon resonance system, additional surface eff ects become visible when using this charge based detection method. Furthermore, we demonstrate the eff ect of sensor area on signal-to-noise ratio and estimate the theoretical limit of detection.
Label-Free FimH Protein Interaction Analysis Using Silicon Nanoribbon BioFETs
Mathias Wipf, Ralph Stoop, Giulio Navarra, Said Rabbani, Beat Ernst, Kristine Bedner, Christian Schönenberger, Michel Calame
ACS Sensors, 1(6), 781-789 (2016), DOI:10.1021/acssensors.6b00089