A Mechanically Stable and High-Sensitivity Glucose-Sensitive Membrane Based on the Entrapping of Immobilized GODs in PVA plus PEG Composite Hydrogels

A mechanically stable and high-sensitivity optical glucose sensitive membrane (OGSM) is prepared by immobilizing glucose oxidases (GODs) onto a mixture of SiO2 mesocellular foams (SiMCFs) and nanoparticles (SiNPs) and embedding ImGODs in the composite gel of polyvinyl alcohol (PVA) and polyethylene glycol (PEG). The OGSM is coated onto a gold-glass sheet to create a surface plasmon resonance (SPR) sensor. For the OGSM consisting of SiMCFs and SiNPs with a mass ratio of 7:3, PVA and PEG with a mass ratio of 4:1, resonance angle of the sensor decreases from about 77.19 degrees to 71.45 degrees, and the average sensitivity is 0.029 degrees/(mg/dL) in a glucose concentration range of 0-200 mg/dL. It was found that the volume fraction of glucose in the OGSM is linear approximately with the concentration of glucose when the concentration of glucose is lower than about 80 mg/dL, as described by the Freundlich isotherm model. The Langmuir isotherm model is suitable for describing the adsorption process of the OGSM for the glucose molecules in a concentration range of 80-200 mg/dL. In addition, Young's modulus of three strips of OGSMs, 0.573 MPa, 0.642 MPa, and 0.649 MPa were obtained, show that the OGSMs have good biomechanical stability.

Automated summary

A mechanically stable and high-sensitivity optical glucose sensitive membrane (OGSM) was prepared by immobilizing glucose oxidases (GODs) onto a mixture of SiO2 mesocellular foams (SiMCFs) and nanoparticles (SiNPs) and embedding ImGODs in the composite gel of polyvinyl alcohol (PVA) and polyethylene glycol (PEG). The OGSM showed linear relationship between glucose volume fraction and concentration when the concentration was below 80 mg/dL, and followed the Langmuir isotherm model at concentrations between 80-200 mg/dL. The OGSMs also exhibited good biomechanical stability with Young's modulus values ranging from 0.573 MPa to 0.649 MPa.