Surface plasmon resonance (SPR) is a phenomenon wherein the reflectance versus angle-of-incidence profile for a thin gold film illuminated with p-polarized light has a distinct minimum at a particular angle. This minimum of reflectance is due to an absorption of the light energy by the surface electron plasma of the metal occurring when the surface- parallel components of the light and plasmon propagation vectors match up. The value of this particular angle of incidence changes in proportion to the degree of adsorption of analytes to the metal film. This allows SPR to be used as a simple, noninvasive, optical tool for measuring the binding of chemical analytes. With a predetermined pattern of chemically specific receptors bound to the gold film, it is possible to detect a variety of species and concentrations of analytes, provided that one has a sensor platform capable of resolving the different reactions in each element of the receptor array. We have developed such a platform which is capable of optically monitoring an array of analyte receptors immobilized on gold coated microscope slides in real time. Moreover, the optical resolution of sensor platform allows the receptors to be micro-patterned.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.