INTEGRATED AMORPHOUS SILICON PHOTODIODE DETECTOR FOR MICROFABRICATED CAPILLARY ELECTROPHORESIS DEVICES

摘要

We have demonstrated that hydrogenated amorphous Si (a-Si:H) photodiodes are sufficiently sensitive to be used as detectors for chemical and biological assays performed on microfabricated capillary electrophoresis devices. A limit of detection of 56 pM for fluorescein flowing in a 50-μm deep microchannel is observed utilizing confocal optics. Moreover, the fluorescence has been successfully detected with a newly designed integrated a-Si:H detector, in which the detector and laser are placed on the same side of the microchip. This optical design is ideal for monolithic integration of the a-Si:H detector technology with VCSEL excitation.