Analysis of optochemical absorbance sensors based on bidimensional planar ARROW microoptics

A new approach for developing absorbance optochemical sensors is presented in this paper. It is based on a planar microoptic circuit where an optochem ically active membrane, which responds selectively to a compound, is deposi ted in the device, yielding a part of the guiding planar structure. Light i s propagated through the membrane, which changes its spectral absorption pr operties and controls the selectivity of the measurements by means of sever al immobilised compounds. This way, high sensitivity of the device can be e asily obtained due to relatively long light paths through the membrane, and low response times can be achieved as the analyte diffusion occurs perpend icularly to the light path and through a thin membrane. Experimental result s on measurements of the concentration of a specific ion in solution using the fabricated sensors are also presented. (C) 1999 Elsevier Science S.A. A ll rights reserved.