Scintillator Light Source for Chemical Sensing in the Near-Ultraviolet

A novel chemical sensor based on a light source composed of a radionuclide and a scintillator is experimentally evaluated. Proper selection of a radionuclide/scintillator combination permits fabrication of a practical light source emitting in the ultraviolet (UV). Such a UV light source is critical for chemical sensors which utilize UV-excitable chromophores or fluorophores. Unlike conventional gas-filled discharge lamps, the developed UV source is compact, inexpensive, simple in design, stable, and highly reliable, and it does not require an external power source. The utility of the new source was demonstrated through construction of sensors for oxygen. This application was selected for experimental evaluation of the new light source since oxygen sensors have been characterized well with conventional light sources. Although the scintillator light source is less intense than conventional sources, its excellent short- and long-term stability provides a reproducibility of fluorescence measurements of about 0.35% RSD. The stability of the scintillator light source suggests its utility in simple single-beam detection configurations.