Chapter 7: Biosensing Devices

Nowadays, individual medication, especially in real-time health monitoring, has become an emerging development focus in current medication systems and industrial production. To realise individual medication in a reliable and rapid protocol, biosensors are deemed to be the key physical devices to carry out this purpose. How to choose the materials for constructing these biosensors has triggered a hot debate in both academia and industry. The requirements for these candidate materials are listed with specific properties, including biocompatibility, chemical resistance and sensitivity. Semiconducting ZnO, with a series of morphologies and configurations, is proposed to work as an ideal biorecognition element to meet those requirements due to its excellent properties of biocompatibility, conductance and piezoelectricity. Biosensors based on enzyme/ZnO modification are central for biological signal sensing device construction and hence have gradually become prevalent in many research programs. In the following chapter, three kinds of biosensor, electrochemical biosensors, field effect transistor based biosensors and high electron mobility transistor based biosensors, are systematically reviewed and discussed.