Silicon nanowire-based biosensors for low concentration detection of salmonella and escherichia coli in complex mixtures

Document Type

Conference Proceeding

Publication Date



Department of Electrical and Computer Engineering


We report on the exploration of top-down fabricated silicon nanowire-based biosensors for low concentration multiplexed detection of bacterial analyte in aqueous solutions. Utilizing a multichannel biochip consisting of thirty- two 70 nm diameter back-gated silicon nanowire sensors we have demonstrated the ability to multiplex the detection of Salmonella and Escherichia coli in 500 CFU/ ImL concentration mixtures with a 500,000 CFU/mL concentration of confounding bacteria suspended in phosphate buffered solution. The biochip was produced with a CMOS compliant top-down fabrication process developed at Michigan Technological University that improves the repeatability of the electrical performance of the nanowire sensors over previous reported methods. These nanowires were selectively coated with a thin polyaniline layer by an electrochemical deposition process. Selectively immobilized to the conductive polymer were single- stranded DNA aptamers and site blocking was used to limit false positives. We expect that this nanowire sensor will be advantageous for rapid diagnostic testing and presumptive positive testing for applications that require quick low concentration detection.

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©2018 IEEE. Publisher’s version of record:

Publication Title

2018 IEEE 13th Nanotechnology Materials and Devices Conference (NMDC)