High performance fluorescent optical sensor

An optical sensor device for determining the presence or concentration of an analyte, comprising:

• a substrate;
• a light source for emitting light primarily of a preselected wavelength upon energization, mounted on a surface of said substrate;
• a light detector for detecting light incident thereon and generating an electrical signal responsive thereto, mounted on said surface adjacent to said light source, and being separated therefrom by a light shielding baffle;
• a waveguide formed over said light source and said light detector;
• said waveguide having a mean thickness corresponding to a far field emission point of said light source;
• and
• an analyte-permeable indicator matrix disposed on an outer surface of said waveguide, said indicator matrix containing light-emitting indicator molecules whose light emission is attenuated or enhanced by the presence of analyte in said matrix, said indicator molecules being selected such that the wavelength emitted by the light source excites light emission in the indicator molecules;
• wherein said light detector generates an electrical signal responsive to light incident thereon emitted by said indicator molecules.