Gold-graphene oxide based nanocomposites for glucose biosensing application

Glucose is necessary fuel for all cells in our body at normal levels. Today, a large part of our world population is suffering from hyperglycaemia. Its detection in blood samples has to be quick and easy. Although several glucose detecting biosensors are available in the market these days, but still there is a need for highly sensitive and low detection limit sensors. One of the most fascinating areas of biosensor design involves the incorporation of carbon-based nanomaterials, like, carbon nanotubes, graphene and graphene oxide [1]. Graphene, a 2D carbon nanomaterial has grasped the world wide attention due to its extraordinary chemical and physical properties [2]. But, it has got a limitation due to its insolubility in most of the solvents. Its functionalized form, graphene oxide (GO), has overcome this limitation as it contains oxygen containing functional groups (-COOH, -OH, -O-). So, GO posses an inherent property for sensing applications [3]. Although, immobilization by enzymes on graphene oxide solely can be an alternative for biosensing applications, further studies need to be done for this approach. Also, GO-based nanocomposites provide high surface and hence better mass transport of the reactants to the actives sites on the electrode which enhance their electrochemical activities. Among several candidates, gold (Au) nanoparticles are considered as superior due to biocompatibility, large surface area and low toxicity [4]. In this work, enzyme-less AuGO nanocomposites with two different concentrations were prepared and used as working electrode for glucose sensing. A comparative study of electrochemical properties of both the systems has been done. Figure1. Cyclic voltammetry curves for Au-GO nanocomposites of two different concentrations.