ZnO modified gold disc: A new route to efficient glucose sensing

Surface of a gold disc was modified by depositing ZnO film electrochemically. AFM analysis of the film shows c-axis oriented pillar like structures grown normal to the surface. Sensor surface was prepared by immobilizing glucose oxidase (GOD) on the ZnO modified gold disc. Different concentrations of glucose (50-1000 ng/ml) were taken to monitor the sensor response. Sensor was found to be highly sensitive to low concentrations of glucose and sensitivity increases linearly in the range of 50-250 ng/ml. The high sensitivity of the ZnO modified gold disc may be attributed to the SPR induced electron transfer between the two systems (i.e. Au and ZnO). The work indicates promising application of the system as a tool for studying sensitive bio-specific interactions, with further development of highly sensitive and selective bio-molecular and chemical SPR based optical sensors.