Performances of on-chip integrated amorphous silicon photodiodes for chemiluminescence and bioluminescence-based assays

Chemiluminescence (CL) and bioluminescence (BL)-based microfluidic chips are being increasingly proposed for clinical, agrofood and environmental analyses . Although offering high detectability and specificity, CL reactions generally involve the emission of low light levels, thus requiring highly sensitive detectors for their sensitive measurement. To enable point-of-care (POC) applications, full integration of all the system components in a low-cost microfluidic platform is required. Herein, we describe a microfluidic-based analytical device integrating an array of 16 hydrogenated amorphous silicon (a-Si:H) photodiodes [3] for on-chip detection of CL signals and the evaluation of its analytical performance, as compared with a state-of-the-art cooled slow-scan charge coupled device (CCD)-based acquisition system (Night Owl LB 981, Berthold Technologies). The a-Si:H photodiodes, which are p-doped/ intrinsic/n-type stacked structures, were deposited by Plasma Enhanced Chemical Vapour Deposition (PECVD) on a glass substrate covered with an indium tin oxide (ITO) layer. An array of polydimethylsiloxane (PDMS) microwells were bonded to the opposite side of the glass for CL measurements.