Poly(dimethylsiloxane)-based packaging technique for microchip fluorescence detection system applications

A simplified integration process including packaging is presented, which enables the realization of the portable fluorescence detection system. A fluorescence detection microchip system consisting of an integrated p-i-n photodiode, an organic light-emitting diode as the light source, an interference filter, and a microchannel was developed. The on-chip fluorescence detector fabricated by poly(dimethylsiloxane) (PDMS)-based packaging had a thin-film structure. A silicon-based integrated p-i-n photodiode combined with an optical filter removed the background noise, which was produced by an excitation source, on the same substrate. The active area of the finger-type p-i-n photodiode was extended to obtain a higher detection sensitivity of fluorescence. The sensitivity and the limit of detection (LOD; S/N = 3) of the system were 0.198 nA/mu M and 10 mu M, respectively.