Chapter 9 Optical chemical sensors and biosensors

Abstract

Publisher Summary Optical chemical sensors and biosensors represent integrated analytical systems employing optical transduction. In these systems, chemical measurement is performed based on the interaction of light with a chemical system and the subsequent conversion of the resulting optical signal into an electrical signal. Optical fibers are often used as the integrating medium, linking the components of an optoelectronic instrumentation with a molecular recognition element that generates a response in the presence of the analyte. These devices encode chemical information through an optical signal traveling in the optical fibers. The optical fiber chemical sensor consists of the following basic components: (1) an optical fiber, (2) optoelectronic instrumentation, and (3) a solid-phase molecular recognition element. The instrumentation associated with optical fiber chemical sensors is similar to that involved in spectrophotometers. Optical fiber sensors can be designed to operate in two possible modes: (1) as an extrinsic sensor, wherein the fiber functions merely as a light guide for the probing radiation; and (2) as an intrinsic sensor, wherein the fiber acts as the transduction element.