Chapter 16 - Functionalized nanomaterials for chemical sensor applications

Abstract

Materials existing in nanoscale dimensions display unique physiochemical properties compared to their bulk counterparts. With a touch of innovation, these unique properties can be used in various applications such as a catalyst for a more effective conversion process in the chemical industry or as a signal transducer for sensing purposes. Despite the encouraging application potential, continuous research is being carried out to further enhance nanomaterial (NM) performance for better efficiency. One method of performing functionalizations of NMs is to add additional features to their existing unique properties. The synergistic effect of added features enables multifunctional operations to occur simultaneously helping to obtain the intended outcomes. Functionalization is particularly important in the case of developing chemical sensors using NMs. NMs, by default, have a large surface area per volume due to their small size, but they must also be able to have a specific interaction with a particular analyte. This interaction is used to trigger the change in the physical property of the NMs, and the degree of change can be correlated to the amount of analyte and adapted as a sensing signal. When the need for interaction with a particular analyte is ignored and the interaction is of a nonspecific type, the change in the signal will not generate any specific analytical information. By performing the functionalization, a specific binding receptor can be introduced to the surface to enhance the specific binding. This offers the option to alter the specificity of the sensing probe, while using the same type of nanomaterial as the core signal transducer. This chapter covers the fundamental characteristics of NMs, the engineering aspect of NMs functionalization, and the major applications of functionalized NMs as sensing receptors.