Laser-Excited Synchronous Luminescence Spectroscopy

Abstract
The use of lasers as excitation sources for molecular luminescence often results in improvements in sensitivity and limits of detection (LODs). Synchronous luminescence (SL) spectroscopy, in which both excitation and emission wavelengths are scanned simultaneously, provides a convenient means to improve selectivity (often dramatically) in the analysis of multicomponent mixtures using room-temperature luminescence. We report here on the first use of a dye laser as an excitation source for SL at room temperature. The performance of the laser synchronous luminescence (LSL) system is described for the analysis of four polyaromatic compounds; for one of these—tetracene—the LOD was 680 zeptomoles (10−21 mol) in the volume probed by the laser. In addition to impressive sensitivity and selectivity, the laser system used is quite small and can be considered as an attractive source for portable SL instruments designed for in-field screening of environmental samples.