Plasma-Fabricated Surface Plasmon Resonance Chip for Biosensing

This work reports the fabrication of a biosensing chip surface designed for plasmonic detection, and features a layer of noble metal nanoparticles encapsulated as a sandwich within amine-functionalized polysiloxane layers formed by plasma-enhanced chemical vapour deposition. The collective surface plasmon resonance (CSPR) phenomenon characteristic of a dense particle layer is demonstrated for encapsulated gold nanoparticles of different diameters. Biomolecular immobilization is carried out through the amine functional groups that are part of the encapsulating layer. The detection of biomolecular binding events at the sensor surface is demonstrated both by a shift in resonance wavelength at constant angle of incidence using SPR-enhanced spectroscopic ellipsometry and by detecting the angular shift in resonance in a commercial SPR instrument (Biacore (R)). Taken with other results, this work shows how a complete SPR chip can be assembled by a rapid sequence of operations in a single plasma chamber.