Fabrication of a chemosensor array on a microfluidic device by a simple gel-based method

A simple gel-based method for fabricating chemosensor arrays on microfluidic chips is described. A microfluidic sensor array has allowed the miniaturization and increased the parallelism of many common functions for high-throughput analysis. However, the patterning of a sensor array on a chip architecture by using traditional fabrication methods is rather complicated. In this study, microchannels fabricated by a simple replica molding method were used to define the pattern of a chemosensor array on a poly(dimethylsiloxane) (PDMS) substrate. Calcium ion dependent fluorescent dye Fluo-3 was used as the sensitive material to validate the proposed method. Four calcium chloride samples and two commercial milk products have been analyzed with this microfluidic chip by fluorescent intensity scanning. All results could be obtained within several minutes, and the minimum detectable calcium ion concentration was less than 50 nM. The obtained results indicate that the proposed method is able to serve as an improved technology for fabricating chemosensor arrays on microfluidic chips for high-throughput analysis.