Prism-Based Surface Plasmon Resonance for Dual-Parameter Sensing

Abstract

A simple method to construct a dual-channel in a prism-based surface plasmon resonance sensor for dual-parameter monitoring is proposed. The metal layer (sensing area), attached to the prism, is half-covered with a polymer in order to generate two individual sensing sections. In this paper, eight different sensor structures (prism/metal/polymer) were analyzed. The prisms are made of NSK16 or SF10 glass and coated with gold or silver films. Half section of the metal films is covered with Polydimethylsiloxane (PDMS) or Poly-methyl methacrylate. The sensor is based on angle interrogation, the laser beam is aligned to be incident upon the interface of the bare and polymer sections. The resonance conditions are different at each pad, due to the refractive index (RI) mismatch, thus the intensity of the reflected signal presents a pair of well-defined resonance dips in series. The sensitivity of these dips to RI and temperature (T) changes was numerically analyzed. Finally, to demonstrate the feasibility to monitor RI and T, simultaneously, a surface plasmon resonance sensor was constructed using a NSK16 glass prism coated with a thin gold film, which was half-covered with PDMS.