Biosensor array microsystem on a CMOS amperometric readout chip

A single-chip integrated microsystem with a CMOS amperometric circuit, on-chip electrodes, a protein-based biointerface, and packaging for biosensor arrays is presented. A 2×2 gold electrode array was fabricated on the surface of the CMOS instrumentation chip. An all-parylene packaging scheme was developed for compatibility with liquid test environments as well as a harsh piranha electrode cleaning process. Proper operation of the chip was demonstrated with electrochemical and biological cyclic voltammetry experiments. A cytochrome PpcA protein interface was implemented to measure concentrations of Fe-NTA using the integrated amperometric microsystem.

I. Introduction

Miniaturized sensor arrays are capable of parallel analysis of multiple parameters. Because of the distinct advantages of microsystem platforms, there has been a trend to integrate sensor arrays onto the surface of silicon chips and perform measurement using on-chip CMOS electronics [1]–[3]. At the same time, there is a great opportunity to expand lab-on-chip solutions that replace bulky bench top sample analysis tools with simple, low power, portable systems. The fabrication compatibility between many bio/chemical sensor interfaces and CMOS technology makes a CMOS circuit an outstanding candidate for a silicon-based lab-on-chip solution [4].