7 - Noble metals and nonnoble metal oxides based electrochemical sensors

Abstract

During recent years, nanotechnology has become one of the most important fields in analytical chemistry. Nanostructures with different materials, sizes, structures, and as a result, different properties, have been significantly used in different methods of analytical chemistry. Electrochemical sensors based on nanomaterials have attracted the scientific society’s enormous interest as effective analytical techniques for various applications, including pharmaceutical analysis, food safety, clinical diagnostics, monitoring of health, and environmental monitoring. So far, a wide range of nanoparticles, including metal nanoparticles, semiconductor nanoparticles, carbon-based nanoparticles, ceramic nanoparticles, polymeric nanoparticles, lipid-based nanoparticles, etc., have been used to fabricate electrochemical sensors. A group of nanomaterials is noble metal nanoparticles (gold, silver, platinum, palladium) that have been widely utilized in the manufacture of electrochemical sensors. Noble metal nanoparticles have unique properties such as nonreactiveness, low cytotoxicity, biocompatibility, easiness of surface functionalization, high reduction potential, and size-dependent electrical properties, making them a practical choice of surface modification materials for electrodes. Also, metal oxide nanoparticles (Fe2O3, Fe3O4, MnO, TiO2, CuO, Cu2O, ZnO, etc.) with diverse morphologies are widely utilized in the construction of electrochemical sensors due to their excellent electrical and photochemical properties, great stability, and high surface area. This chapter will focus on the different properties of noble metal and nonnoble metal oxides nanoparticles. Furthermore, the reasons for their use in the fabrication of electrochemical sensors will be investigated. Finally, we will present the applications of noble metals and nonnoble metal oxides-based electrochemical sensors in various fields.