Metal Oxides and Sulfide-Based Biosensors for Monitoring and Health Control

Monitoring health conditions with low-cost, portable devices is a target for diseases such as diabetes, which is now performed by detecting the glucose level in blood samples. Since commercial biosensors suffer with limited enzyme stability and shelf-life problems, novel materials have been exploited, including metal oxides and sulfide nanostructures. These materials are suitable for detection with electrochemical methods owing to their high surface area-to-volume ratio, selectivity, sensitivity, and fast response properties. In this chapter, we discuss some of these nanostructures to detect glucose through nonenzymatic reactions, which are advantageous to increase robustness and shelf-life of biosensors. Furthermore, the work on metal oxides and sulfide-based biosensors is being extended with the design of hierarchical nanostructures to enable high sensitivity, rapid response, and detection of multicomponent elements following the electronic tongue concept. The challenges and prospects for glucose biosensing are also highlighted.