Enzyme-based and enzyme-free metal-based glucose biosensors: Classification and recent advances

Due to its dangerous complications, uncontrolled diabetes affects every part of the body. Owing to advances in various scientific fields, biosensors for blood glucose (Glu) analysis have different advantages, such as selectivity, measurement accuracy, response time, sensor stability duration, etc. As a result, progress is being made in developing better blood Glu sensors. When it comes to monitoring blood sugar and other physiological analytes in portable and non-invasive devices, electrochemical voltammetry sensors are one of the most promising sensors. The advantages of this method include shorter analysis times, selective measurement, cost-effectiveness, and simple techniques using low-power circuits. Three different generations have witnessed advances in the field of enzyme sensors. In addition, many advances have been made in the field of non-enzymatic sensors, noble and transition metals, multimetallic nanomaterials and alloys, and metal oxide-based sensors using various techniques and materials based on nanotechnology and chemical innovations to reduce the cost and improve the sensitivity and accuracy of Glu sensors. However, there are still many shortcomings regarding the possibility of selectivity, thus, no types of sensors are superior in terms of measurement factors, and more research is needed in this context.