Patent ID: 8038946

Claim:
A passive sampling device comprising: a waveguide having first and second sides; an AFP compound carried by said waveguide, said AFP compound fluoresces when exposed to ultraviolet light, said fluorescence of said AFP compound is quenched by exposure of said AFP compound to a target analyte; a reference standard carried by said waveguide, said reference standard, when exposed to ultraviolet light, fluoresces at a wavelength distinct from the fluorescence of said AFP compound, and wherein fluorescence of said reference standard is not substantially quenched when said reference standard is exposed to said target analyte; wherein said AFP compound is carried by said first side of said waveguide and said reference standard is carried by said second side of said waveguide; wherein said AFP has a thickness of about 100 angstroms to about 1 micron; and wherein said reference standard has a thickness of about 100 angstroms to about 1 micron.