Diabetes is the most common disease currently affecting the more than 371 million people. Blood glucose irregulation is the main cause of diabetes. Many methods are currently available such as artificial pancreas which consist of the glucose sensors, insulin pump and controller. The process of testing blood glucose level was quite tedious in past days. But now a days glucose biosensors are used to test the blood glucose level. The currently available biosensors are electrochemical type. These glucose biosensors are very sensitive, easy to maintain and their cost is too low. Glucose biosensors are basically based upon the oxidation of glucose with molecular oxygen. But still many important challenges remaining to achieve a reliable glucose monitoring device.