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

Abstract

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.

Temozolomide Efficacy and Metabolism: The Implicit Relevance of Nanoscale Delivery Systems

“…Nano-spray drying plants are not designed for the production of nanopowders in large quantities. Powders obtained in this way can be used where reproducible morphology and purity of the product are necessary, for example, in the synthesis of drug carriers [ 120 , 121 ].…”

Multifunctional Dyeing of Wool Fabrics Using Selenium Nanoparticles

“…[ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ] In recent years, several approaches to metal and metal oxide NP fabrication and application have been developed to impart functionalities to different types of textile substrates [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. In addition, nanomaterials, such as gold and silver nanoparticles, stabilized by opportune functional capping agents, have been used as a novel class of functionalizing nanofillers either themselves [ 24 , 25 , 26 , 27 , 28 , 29 ] or for the functionalization of different types of materials (such as concrete, glass, geopolymer and also embedded in coloring or antibacterial coatings), especially for textile fabrics [ 30 ].…”

Preparing Copper Nanoparticles and Flexible Copper Conductive Sheets

“…The second stage is nucleation, in which the metal atoms in the solution continue to collide with one another, clustering to form nuclei. The final stage is growth, in which more solids are gradually deposited on the surface of the nucleus until the nucleus grows to a critical size, thereby forming a nanoparticle [ 5 , 18 , 19 , 20 ]. However, most of the chemicals employed in metallic nanoparticle preparation are toxic, and improper treatment of these chemicals could lead to environmental pollution.…”

“…Therefore, the preparation of environmentally friendly, low-temperature-sintering metallic nanoparticles has become a research trend [ 21 , 22 , 23 , 24 ]. In past research [ 18 , 25 , 26 ], reports clearly demonstrated that ascorbic acid is a popular reducing agent. It is a natural and mild reducing agent with antioxidant properties and is widely used as a food preservative.…”