Two-color amorphous silicon photodiode for multicolor detection of labeled DNA

In this work we present a system for the detection of labeled DNA by means of a two-color amorphous silicon photosensor. The device is a p-i-n-i-p structure, whose spectral response is controlled by tuning the voltage applied to its electrodes. The thicknesses of the different layers has been optimized to match the emission spectra of the two utilized fluorochromes. Minima detectable concentrations range in the order of few nmol/l. Very good linearity in the photosensor responses, comparable with those of commercial equipment, has been achieved