Sol-gel silica planar waveguide doped with green fluorescent protein for in-line biosensors

Abstract

The authors report in-line detection of green fluorescent light from planar waveguide biosensors made of sol-gel silica and doped with green fluorescent protein (GFP). GFP is immobilized on the surface of polystyrene microbeads. Green fluorescence, with a center wavelength of 509nm, is observed for an excitation with a pump laser power of 3mW at 488nm wavelength. GFP in the sol-gel waveguide shows visible fluorescence for 30days after fabrication. A citrate buffer (56mM, pH 4.0) reduced the fluorescence power output. These results enable the development of real-time, in-line, remote fiber biosensor networks.