We demonstrate an AlGaN light-emitting diode LED giving pulses of ϳ600 ps full width half maximum, 0.35 ␮W average power, 0.6 mW peak power, and ϳ12 nm bandwidth at 295 nm. This source is ideal for protein intrinsic tryptophan fluorescence decay research without the unwanted excitation of tyrosine and paves the way to lab-on-a-chip protein assays using fluorescence decay times. Fluorescence decay and anisotropy decay measurements of human serum albumin are reported and the usefulness of the 295 nm LED demonstrated in comparisons with a nanosecond flashlamp and LEDs with nominal wavelength emission of 280 nm. © 2005 American Institute of Physics.[ DOI: 10.1063/1.1984088͔]