Design and fabrication of array format SPR chips in microstructure monolayers detection

Abstract

Surface plasmon resonance (SPR) has been used in biosensing techniques since the 1980s. Optical coupling to surface plasmon resonance is evidenced by attenuated total reflection method. SPR sensors characterize the thickness and index of refraction changes of ultrathin films at noble metal surfaces. A SPR chip can be a disposable component for the SPR sensing system. The array format SPR chip performs as a parallel detection platform to various biomolecules immobilized on sensor surface. With the advantages of high sensitivity and label free sample preparation of SPR techniques, array format SPR chip holds a strong capability in real time imaging system. In this research, we demonstrate the design and fabrication of array format SPR chip. A 50 nm gold layer is thermally evaporated on substrate. We use alkanethiols group to build highly organized microstructures on gold surface after evaporation The self-assembled alkanethiol monolayers spontaneously form highly organized monolayers on gold surface and immobilize biomolecules on gold surfaces. The final parallel detection goal is reached by SPR imaging system. A SPR imaging system consists of HeNe laser source, array format SPR chip, and photodetector. SPR imaging investigates in-situ measurement and provides high spatial resolution in micro scale biosensing.