Concept design of a UV light-emitting diode based fluorescence sensor for real-time bioparticle detection

A concept design of an ultraviolet (UV) light-emitting diode (LED) based “detect-to-warn” bioparticle sensor operating in the two modes of real-time recognition of spectral and decay-time signatures of autofluorescence of selectively excited aromatic amino acids within a specific environment of bioparticles is presented. The sensing scheme is optimized for the discrimination of Bacillus globigii spores against common airborne interferants. It contains a deep-UV LED emitting at 280 nm that is harmonically modulated at a frequency of 70 MHz and a dual-channel fluorescence detector with the spectral windows at 320 nm and 400 nm that match the characteristic peak and dip of the spore fluorescence spectrum, respectively, wherein the phase of fluorescence signal waveform simultaneously resolved in the 320-nm channel. The output parameters of the sensor are the ratio of fluorescence intensities in the two spectral windows and the phase shift of the 320-nm fluorescence waveform in respect to that of excitation. The proposed concept sensor is expected to feature an improved ability of the recognition of bioparticles in comparison with only fluorescence spectral discrimination based sensors.