Fibre-optic sensors in biomedical sciences

Abstract

Optical fibres can be used for remote sensing of chemical and physical parameters. The usual approach is to provide the fibre end with a suitable indicator chemistry or a material that responds to the parameter of interest. In contactwith the sample, the intensity of reflected, scattered, or re-emitted light is the analytical signal. Aside from severaladvantages of optical sensors over electrochemical ones (for instance, lack of reference cells and immunity towards electromagnetic interferences), the use of fibres can be advantageous when the samples are Inaccessible, for instance, in case of in-vivo experiments. The principles of waveguide spectroscopy are briefly outlined, and representative examples of fibre-optic sensors for temperature oxygen, pH, carbon dioxide and electrolytes are given. Apart from these parameters, which also may be sensed by other techniques, optical sensors have been developed that are based on quite new principles and which can make them useful for sensing glucose, enzyme activities, anaesthetics and antigen-antibodyinteractions. Potential fields of application are presented and current trends and concepts discussed in a final section. © 1987 IUPAC