Enhanced Bio-molecular Sensing Capability of LSPR, SPR-ATR Coupled Technique

This paper gives a comparative study of two of the SPR techniques i.e. Localised surface plasmon resonance (LSPR) and Surface plasmon resonance-Attenuated total reflection (SPR-ATR) technique and coupling of the two techniques for bio-molecular sensing applications. Silver nanoparticles prepared by using Exploding wire technique and silver thin films prepared by Thermal evaporation were used. Different concentrations of Bovine serum albumin (BSA) were taken for our studies. For LSPR studies, UV-Visible spectrometer was used and a home-made prism coupled ATR-SPR set-up was used for the study of SPR of the thin films. From the comparative studies of our system ATR-SPR method is comparatively a better tool for the optical bio-sensing. Again when bio-molecules tagged with nanoparticles are used, the sensitivity is found to be enhanced abruptly. So the use of both nanoparticles and thin film in the ATR-SPR method gives the best results which could be used as an excellent tool for sensing of bio-molecules and as an effective biosensor.