NEAR-INFRARED SURFACE-PLASMON RESONANCE IN SILICON-BASED SENSOR - NEW OPPORTUNITIES IN SENSITIVE DETECTION OF BIOMOLECULES FROM AQUEOUS-SOLUTIONS BY APPLYING MICROSTEP FOR DISCRIMINATING SPECIFIC AND NONSPECIFIC-BINDING

We report the application of near-infrared surface plasmon spectroscopy to study the sensitive detection of the binding of proteins to functionalized surfaces, Working at 1300 nm, where both water and silicon are transparent, the method is of particular interest for biosensors based on silicon technology. We describe the application of thin functionalization layers forming a step on the sensor surface. Employment of such a step for discriminating specific and non-specific binding of biomolecules is suggested: measuring surface plasmon resonance (SPR) with a single near-infrared laser and detector chip on a single sensor spot shows simultaneously adsorption to one surface in comparison to a reference surface. As a model for this step, a few monolayers of phthalocyaninatopolysiloxane, a 'hairy' rod-like polymer, are deposited by the Langmuir-Blodgett technique. As a model system, we use the binding behaviour of bovine serum albumin to two different kinds of surface.