Portable Optoelectronic System for Monitoring Enzymatic Chemiluminescent Reaction

Abstract

This work presents a portable lab-on-chip system, based on thin film electronic devices and an all-glass microfluidic network, for the real-time monitoring of enzymatic chemiluminescent reactions. The microfluidic network is patterned, through wet etching, in a 1.1 mm-thick glass substrate that is subsequently bonded to a 0.5 mm-thick glass substrate. The electronic devices are amorphous silicon p-i-n photosensors, deposited on the outer side of the thinner glass substrate. The photosensors, the microfluidic network and the electronic boards reading out the photodiodes’ current are enclosed in a small metallic box ($10 \times 8 \times 15\,\mathrm{cm}^3$) in order to ensure shielding from electromagnetic interferences. Preliminary tests have been performed immobilizing horseradish peroxidase on the inner wall of the microchannel as model enzyme for detecting hydrogen peroxide. Limits of detection and quantification equal to 18 and 60 $\upmu$M, respectively, have been found. These values are comparable to the best performances reported in literature for chemiluminescent-based optofluidic sensors.