Metal Oxide Nanostructures in Sensing

Metal oxides are well-known materials for the sensor and biosensor applications. In fact, the surface of metal oxides is a key factor for effective interaction with target molecules. Tailoring of the surface properties of metal oxide allows improving sensitive properties. The recent advances in nanotechnology open new possibilities for applications of metal oxides. Reducing the grain size to nanoscale increases the active surface area and induces new effect due to the quantum confinement such as bandgap widening, room temperature photoluminescence, etc. The novel physical effects in metal oxide nanostructures could be used for the development of sensor tool with advanced parameters.This chapter is targeted to show advances in the application of metal oxide nanostructures as sensor elements and biosensor transducers and to demonstrate future prospects of metal oxide-based sensing elements. The chapter's structure consists of three main subchapters: metal oxide gas sensors, metal oxide chemical sensors, and metal oxide biosensors. Within these subchapters, the main attention is focused on the physical methods of signal registration (electrical, optical, electrochemical, etc.), functionalization and biofunctionalization of metal oxide surface, operation temperatures of metal oxide gas sensors, sensitivity range, detection limits, and selectivity. The novel prospect metal oxide nanomaterials and methods of detection are discussed.