PDMS microdevice with built-in optical biosensor array for oil-site monitoring of the microenvironment within microchannels

Abstract

Nowadays as cell culture in microchannels becomes increasingly popular, new and convenient ways to closely monitor the cultured cells in the microchannels are essential. With that objective, we managed to merge different technologies, mainly fluorescence based optical sensing, layer-by-layer encapsulation and Poly Dimethyl Siloxane (PDMS) based microfluidics to build a hybrid system which can provide on-site monitoring of the cellular microenvironment within the microchannels. The system is mainly built from two parts: one is the fluorescence quenching based sensing material which changes its fluorescence intensity proportional to the analyte concentration, for example glucose level in the media; the other part of the system is the microfluidic PDMS chip, featuring some nanoliter wells fabricated beneath the microchannels where the cells could be cultured. These nanowells are intended sites for the immobilization of the sensing material followed by the layer-by-layer encapsulation. Some preliminary results show that the system is sensitive in low analyte concentration, while being highly miniaturized, low cost, easy to be customized and with great potential applications in medical diagnostics and environmental monitoring.