Detection of biochemical interactions on a biosensor using tunable filters and tunable lasers

Abstract

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 in a shift in the peak wavelength value of the 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.

1 . A measuring apparatus for detecting a biochemical interaction on a biosensor, the measuring apparatus comprising: a tunable laser light source for generating light having a tunable laser wavelength and for directing the light towards a surface of the biosensor, wherein the tunable laser wavelength is tuned by adjusting a tuning voltage; and a photodiode detector operable to receive light transmitted through the biosensor and to detect a broad band of wavelengths encompassing a wavelength passband, wherein an output of the photodiode detector quantifies an amount of the light transmitted through the biosensor as a function of the tuning voltage. 
     
     
         2 . The invention of  claim 1 , wherein the tuning voltage adjusts the tunable laser wavelength over a range of wavelength that encompasses a biosensor resonant wavelength. 
     
     
         3 . The invention of  claim 1 , wherein the biosensor is illuminated at normal incidence by the tunable laser light source. 
     
     
         4 . The invention of  claim 1 , wherein the tunable laser light source is a vertical cavity surface emitting laser (VCSEL). 
     
     
         5 . The invention of  claim 1 , wherein the photodiode detector detects a minimum in intensity of the light transmitted through the biosensor as a function of wavelength. 
     
     
         6 . The invention of  claim 1 , wherein the photodiode detector detects a wavelength of peak reflected intensity of the light transmitted through the biosensor. 
     
     
         7 . The invention of  claim 1 , further comprising a plurality of tunable laser light sources, wherein where each tunable laser light source illuminates a respective region on the biosensor's surface. 
     
     
         8 . The invention of  claim 1 , wherein the biosensor comprises a calorimetric resonant optical biosensor. 
     
     
         9 . The invention of  claim 1 , further comprising a biosensor readout interface.