A CMOS-compatible optical biosensing system based on visible absorption spectroscopy

Abstract

A CMOS-compatible optical biosensing system based on visible absorption spectroscopy is proposed. Within the compact prototype, the CMOS sensor consisting a P(+)/N(well) finger photodiode and a transimpedance amplifier (TIA) is implemented in a standard 0.35-mu m CMOS technology. The ABTS/H(2)O(2)/HRP method is adopted as the ground for medical diagnosis, Experimental results demonstrate that the minimum concentration successfully detected for H(2)O(2) is 1 mu M. The detection limit is one order of magnitude better than a traditional CMOS biosensor, and comparable to a commercial spectrophotometer.