ABSTRACT
Upon shining a light on their surfaces, metal nanostructures display fascinating optical absorption in the UV, visible, and near infra-red (NIR) regions. These exquisite optical properties of metal nanostructures are known as surface plasmon resonance (SPR). Silver, gold, platinum, palladium, and aluminum are some examples of metal nanostructures displaying SPR. Using SPR as the identifying tool, metal nanostructures have found a plethora of applications in the sensor, photodetector, photovoltaics, biomedical, and photocatalysis fields.
Herein, we confine our discussion to the fabrication of functionalized gold nanostructures and their fascinating attributes. We start our discussion with the physical and chemical techniques for the preparation of functionalized gold. Lithography, chemical vapor deposition, physical vapor deposition, plasma sputtering, and laser ablation are some of the physical techniques used for the fabrication of gold. The different chemical approaches for functionalized gold are as follows: citrate reduction using the Turkevich method, the thiol-protected method of Brust–Schiffrin, the polymer-protected method, the electrochemical method, and the photochemical method. These strategies generate spherical as well as anisotropic gold nanostructures including nanospheres, nanowires, nanorods, nanoprisms, and nanodisks. By the end of the chapter, we have discussed the application of the various forms of functionalized gold nanostructures in chemical sensing, biosensing, and catalysis.
