A High-Sensitivity and Broad-Range SPR Glucose Sensor Based on Improved Glucose Sensitive Membranes

Abstract

An improved glucose sensitive membrane (GSM) is prepared by immobilizing glucose oxidase (GOD) onto a mixture of silica mesocellular foams (SiMCFs) and SiO2 nanoparticles (SiNPs) and then trapping it in a polyvinyl alcohol (PVA) gel. The membrane is coated onto a gold-glass sheet to create a surface plasmon resonance (SPR) sensor. A series of experiments are conducted to determine the optimized parameters of the proposed GSM. For a GSM with a component ratio of SiMCFs: SiNPs = 7: 3 (mass rate), the resonance angle of the sensor decreases from 68.57° to 63.36°, and the average sensitivity is 0.026°/(mg/dL) in a glucose concentration range of 0 mg/dL‒200 mg/dL. For a GSM with a component ratio of SiMCFs: SiNPs = 5: 5 (mass rate), the resonance angle of the sensor decreases from 67.93° to 63.50°, and the sensitivity is 0.028°/(mg/dL) in a glucose concentration range of 0 mg/dL‒160 mg/dL. These data suggest that the sensor proposed in this study is more sensitive and has a broader measurement range compared with those reported in the literature to date.