Light Scattering by One-Dimensional ZnO Nanorods and Their Applications in Optical Sensing

Zinc oxide (ZnO) is a versatile metal oxide semiconductor material with remarkable optical and electrical properties. Particularly, the one-dimensional (1D) ZnO nanorods are of great interest because of their superior as well as tunable optical scattering properties and availability of simple synthesis methods using which they can be grown on a variety of substrates. This makes them a top choice material for designing low-cost, sensitive, and robust optical sensors. The chapter discusses the light scattering properties of 1D ZnO nanorods and their utilization in designing optical sensors for the detection of chemical and biological substances. The physical and chemical properties of ZnO and the theory of light scattering by 1D ZnO nanorods are explained. The fundamental sensing mechanism of the optical sensors based on light scattering by ZnO nanorods is described to provide a clear insight into the role of the ZnO nanorods in these optical sensors. A few examples of various optical sensors developed to detect chemical and biological species are given, and the strategies for improving the sensitivity of sensors and reducing the cost are also discussed. A future outlook of such emerging optical sensors is discussed at the end.