High-selectivity optical detection in microfluidic systems for clinical diagnostics

Abstract

This paper presents a microfluidic system for determining the protein concentrations in human biological fluids (e.g. urine, blood or serum) with a highly sensitive and selective optical photodetector based on a Fabry-Perot filter. The microsystem consists of two wafers: a Pyrex glass wafer containing the microlaboratory (microchannels to carry chemical reagents and sample solutions) and a silicon wafer that includes the protein detection system and readout electronics. The optical channel operates in the visible spectral range. A FWHM < 3 nm and finesse of 36 for narrow band operation is demonstrated in albumin concentration detection. Detection system compensation techniques are also presented.