Researchers have demonstrated visible-blind avalanche photodiodes capable of detecting single photons in the ultraviolet region (360-200 nm). This is a world’s first for demonstrating back-illuminated single photon detection from a III-nitride photodetector. Once optimized, discrete detectors could be combined with the ultraviolet LEDs to create an inexpensive detection system capable of identifying the unique spectral fingerprints of a biological agent attack.