Synthesis, Chemical-Physical Characterization, and Biomedical Applications of Functional Gold Nanoparticles: A Review

Relevant properties of gold nanoparticles, such as stability and biocompatibility, together with their peculiar optical and electronic behavior, make them excellent candidates for medical and biological applications. This review describes the different approaches to the synthesis, surface modification, and characterization of gold nanoparticles (AuNPs) related to increasing their stability and available features useful for employment as drug delivery systems or in hyperthermia and photothermal therapy. The synthetic methods reported span from the well-known Turkevich synthesis, reduction with NaBH4 with or without citrate, seeding growth, ascorbic acid-based, green synthesis, and Brust-Schiffrin methods. Furthermore, the nanosized functionalization of the AuNP surface brought about the formation of self-assembled monolayers through the employment of polymer coatings as capping agents covalently bonded to the nanoparticles. The most common chemical-physical characterization techniques to determine the size, shape and surface coverage of AuNPs are described underlining the structure-activity correlation in the frame of their applications in the biomedical and biotechnology sectors.

Automated summary

Gold nanoparticles exhibit excellent stability and biocompatibility, making them ideal candidates for medical and biological applications. Various synthetic methods, such as Turkevich synthesis, reduction with NaBH4, seeding growth, ascorbic acid-based, green synthesis, and Brust-Schiffrin methods, have been used to enhance their stability and features. Functionalization of the AuNP surface has led to the formation of self-assembled monolayers using polymer coatings as capping agents bonded to the nanoparticles. Common chemical-physical characterization techniques are used to determine the size, shape, and surface coverage of AuNPs for their biomedical and biotechnology applications.