In this chapter, we discuss the relevant physical and chemical properties of gold nanoparticles that are exploited for analytical applications in a variety of different fields. This chapter was conceived to collect in a single place an overview of the properties of gold nanoparticles that are important for technological applications, with prevalent reference to the scientific literature that has appeared in the last six years. Given the extremely broad expertise needed for an in-depth discussion, the chapter is co-authored with experts in the specific field dealing with optical properties, ab initio calculations of electronic properties, magnetic, electrochemical and chemical properties.
