A LASER PHOTOACOUSTIC SENSOR FOR ANALYTE DETECTION IN AQUEOUS SYSTEMS

Pulsed laser photoacoustic spectroscopy has been used as the basis for sensing analytes in aqueous systems. The spectra obtained with the photoacoustic system are significantly different from conventional transmission spectra and, in particular, the spectra of some organic solvents and alcohols show a marked enhancement in feature strength due to the dependence of physical and thermal factors in the photoacoustic generation process. The photoacoustic process has been shown to be almost immune to the effects of optical scattering, which gives this sensing technique advantages over conventional spectroscopic techniques in the potential application to water-pollution monitoring and to measuring blood-glucose concentrations.