Bioluminescence Detection Using a Novel MEMS Modulation Technique

A novel modulation microelectromechanical systems (MEMS) technique is introduced to overcome the low-frequency (flicker) noise of photodiodes. The transmissive shutter is placed as an add-on device between an optical source and a photodiode, and is implemented as a method to enhance the signal-to-noise ratio, adapted for the detection of low-intensity bioluminescence. The detection of the signal below the noise level of photodetector is demonstrated by implementing a lock-in amplifier that registers the modulated signal at four times the frequency of the electrical excitation signal of the modulator. This work represents the first reported attempt to use a MEMS modulation technique for the detection of low-intensity signals.