A device design of an integrated CMOS poly-silicon biosensor-on-chip to enhance performance of biomolecular analytes in serum samples

Abstract

For on-site clinical diagnosis of biomolecules, the detection performances of most point-of-care (POC) biosensor devices are limited by undesired cross-detection of other non-analyte proteins in patient serum samples and other complex samples. To conquer this obstacle, this work presents a fully integrated bottom-gate poly-silcion nanowire (polySi NW) biosensor system-on-chip (SoC) to enhance the detection performance of cardiac-specific troponin-I (cTnI) concentration levels in serum samples. By applying proper electrical potential at the bottom gate under polySi NW biosensor, the biosensor response to cTnI biomarker can be improved by at least 16 fold in 50% phantom serum samples. The experimental result shows its detection range is from 3.2×10−13M(moll−1)to3.2×10−10M. This enhancement can be attributed to the electrostatic interactions between target biomolecules and voltage-applied bottom gate electrodes. This is the first time that a polySi NW CMOS biosensor chip has shown feasibilities to detect specific biomarkers in serum samples. Therefore, the developed technology paves the way toward on-field applications of CMOS compatible SiNW biosensing technologies and it can be employed for future biomolecular analysis in on-site serum diagnosis applications.