Gold nanoparticles (AuNPs) ranging from 2-200nm in diameter find applications in diverse fields. They show excellent biocompatibility and attractive physicochemical properties. Poly (ethylene) glycol (PEG) surface coatings on gold nanoparticles help in the reduction of protein adsorption, reduce nonspecific interactions with cells and greatly improve the pharmokinetics of these nanoparticles and reduce aggregation of the nanoparticles. PEG layer density depends inversely on the AuNP curvature. Denser coating was possible on smaller AuNPs. AuNPs coated with PEG 5000 exhibited highest colloidal stability. Amine functionalized GNPs which have Poly Ethylene Glycol (PEG) as the ligand or carrier molecule forms a conjugate with siRNA and is extremely useful in RNAi technology. Since it adheres to cell membranes, it may find use in cellular and intracellular targeting in targeted drug delivery applications and also used in biodistribution studies.

功能化颗粒已广泛用于研究纳米颗粒的细胞摄取和靶向药物递送。

Several other specific applications have been listed below:

• Since they adhere to cell membranes, AuNPs are used in cellular and intracellular targeting in targeted drug delivery applications and may also be used in biodistribution studies
• AuNPs may also be used in photothermal therapy and radiotherapy.
• Proposed applications of gold nanoparticles are as:drug delivery agents for cancer therapy, coatings, plastics, nanowire, nanofiber, textiles, catalyst applications.
• They may also be used in carrying siRNA which acts against human prostate carcinoma cells by inhibiting a specific cancer gene.