This review gives details about the application of glucose biosensors in Diabetes. Diabetes is a serious health hazard which also leads to other chronic diseases. Increasing Diabetes cases drive market. It is mostly prevalent in affluent societies due to their lifestyle. Many biosensors have been designed for diagnosis of Diabetes, but still researches are going on to design a classical biosensor. Since last 30 years, only short term glucose measurement in skin are developed, long term use in Diabetic patient of glucose sensor is still not available. In glucose biosensor, nanotechnology based biosensors are most widely used. The behavior of implantable glucose sensors are disappointing in-vivo. Alternative glucose sensing techniques which do not involve tools that break the skin or physically enter the body are still under experiment.