Comprehensive Study of the Effects of Nanopore Structures on Enzyme Activity for the Enzyme Based Electrochemical Biosensors Based on Molecular Simulation.

Assembly of biocompatible nanostructures to retain the enzyme activity and improve the biocatalytic ability is a decisive factor for enhancing the performance of enzyme biosensors. However, there is still a lack of molecular level understandings of the physicochemical interaction mechanism at the interface of biosensor electrodes and enzymes. Here, for the first time at molecular level, the effects of two classic biosensor electrode materials with different electrical properties and morphologies and glucose oxidase (GOD) on retaining the enzyme conformation were analyzed by molecular dynamics simulation. First, for the immobilization of GOD, the interfaces of zinc oxide (ZnO) with different electrical properties and 10 nm diameter ZnO nanopore were studied. Then, to simulate the sensing process when electric voltages are applied, positively charged gold planes and 10 nm diameter gold nanopore were investigated as well. The results showed that the nanopore structure was confirmed to be well adapted for the enzyme conformation retaining compared to the plane structure for both ZnO and gold materials, and they almost fit well with the sensitivity measurement results from many previously reported experimental studies. This study also indicates that molecular modeling of the interactions between biomolecules and functional nanostructures is helpful for developing high performance enzyme nanobiosensors.