Flip-Chip Bonded GaP Photodiodes for Detection of 400- to 480-nm Fluorescence

Gallium phosphide (GaP) PIN photodetectors have been flip-chip bonded onto glass substrates and then studied for their ability to detect capillary fluorescence. The system presents a compact, robust alternative to liquid chromatography and capillary electrophoresis. Linear fluorescence detection of Ciprofloxacin to concentrations of 0.01 ppm was achieved.