An apparatus and method for detection of peak wavelength values of colorimetric resonant optical biosensors using tunable filters and tunable lasers is provided. Biomolecular interactions may be detected on a biosensor by directing collimated white light towards a surface of the biosensor. Molecular binding on the surface of the biosensor is indicated by a shift in the peak wavelength value of reflected or transmitted light from the biosensor, while an increase in the wavelength corresponds to an increase in molecular absorption. A tunable laser light source may generate the collimated white light and a tunable filter may receive the reflected or transmitted light and pass the light to a photodiode sensor. The photodiode sensor then quantifies an amount of the light reflected or transmitted through the tunable filter as a function of the tuning voltage of the tunable filter.