Electrochemical glucose biosensor with the characterization of surface morphology and content of glucose oxidase-glutaraldehyde-cysteine layers on gold electrode

Glucose biosensor containing cysteine (Cys), glutaraldehyde (GA) and glucose oxidase (GOx) onto gold electrode is constructed and already electrochemically tested. Now, the electrochemical behavior of biosensor in human serum is further investigated and supported by morphological characterization of layers for the first time. The morphology and microstructure of layers was examined by Fourier transformed infra red spectroscopy (FTIR), atomic force (AFM) and optical microscopy (OM). The electrochemical indication that the Cys-GA-GOx film on Au surface is not compact and that there were some bare regions which remain catalytically active is supported by AFM and OM results. The construction and the nature of bonding of Au-Cys-GA-GOx biosensor layers is confirmed by the FTIR study.