Realization and optimization of the gold-mesoporous silica based bimodal surface plasmon resonance sensor with digital Gaussian filter

Abstract This work presented a novel biomdal surface plasmon resonance (BSPR) sensor with mesoporous silica film (MSF) and digital Gaussian filter. A modified Stöber solution growth approach was applied to prepare MSF film on the gold film. The conventional SPR sensor was coupled with a digital Gaussian filter to realize the BSPR sensor. After that, the Gaussian parameters were modified and the BSPR angular spectrum was obtained for further sensing experiments. Porosity and thickness of the MSF film were measured and calculated by means of a combination of simulation and measurement. The simulation results indicate that the refractive index (RI) sensitivity of the BSPR sensor could reach 75.11 deg/RIU which is 66.91% higher than the 45 deg/RIU of the conventional gold-MSF SPR sensor. Based on the experiments, the RI resolution of BSPR sensor was improved by 37.1% to 6.61 × 10 −6 RIU, the limit of detection (LOD) for glucose was raised from 320 mg l −1 to 131 mg l −1 , and the LOD for CTAB molecule was raised from 124.98 nM to 63.78 nM when compared to the gold-MSF SPR sensor.