Sensor apparatus and analytical method

Abstract

This invention provides a fiber-optic sensor or analytical apparatus and associated method which utilizes the combination of (a) a solid, semi-solid or liquid sensor body which is capable of selectively dissolving the analyte compound to be detected and analyzed into the sensor body from the mixture or environment in which the compound is present and excluding undesired or interfering components, (b) a radiation source for directly radiating the analyte compound molecules to excite same to an elevated energy state, thereby causing the analyte compound itself to luminesce while dissolved in the sensor body, and (c) a radiation detector for detecting and measuring the light emitted from the excited analyte compound molecules when they return to a lower energy state. The selective dissolving sensor body provides a controlled environment in which both the source light directly excites the analyte molecules and the excited molecules emit light which is detected and measured. This invention thereby provides dual selectivity, first by selectively dissolving the analyte component into the sensor body and second by the direct selective/specific excitation of the analyte compound to cause it to specifically luminesce in a manner known to be characteristic of that compound. Improved sensitivity also is provided by this invention by the direct measurement relationship, i.e, the higher the concentration of the analyte compound, the greater the luminescent signal from the excited analyte compound.