Role of capping agents in the application of nanoparticles in biomedicine and environmental remediation: recent trends and future prospects

Abstract

Capping agents are of utmost importance as stabilizers that inhibit the over-growth of nanoparticles and prevent their aggregation/coagulation in colloidal synthesis. The capping ligands stabilize the interface where nanoparticles interact with their medium of preparation. Specific structural features of nanoparticles are attributed to capping on their surface. These stabilizing agents play a key role in altering the biological activities and environmental perspective. Stearic effects of capping agents adsorbed on the surface of nanoparticles are responsible for such changing physico-chemical and biological characteristics. Firstly, this novel review article introduces few frequently used capping agents in the fabrication of nanoparticles. Next, recent advancements in biomedicine and environmental remediation approaches of capped nanoparticles have been elaborated. Lastly, future directions of the huge impact of capping agents on the biological environment have been summarized.

Keywords: Biomedicine; Capping agents; Environment; Nanoparticles; Nanotechnology.

Fig. 1

Nanoparticles covalently bound with capping agents

Fig. 2

Different types of capping agents utilized in nanotechnology

Fig. 3

Schematic representation of the green synthesis of nanoparticles

Fig. 4

Capping agents of nanoparticles affecting different areas of biomedicine

Fig. 5

Proposed mechanism of antibacterial action of capped/modified nanoparticles

Fig. 6

Comparison of mode of anticancer action of conventional therapeutics versus capped/modified nanoparticles

Fig. 7

Magnetic separation of metal ions from the contaminated water by the use of capped/modified nanoparticles

Fig. 8

Capped nanoparticles undergoing catalytic degradation of 4-Nitrophenol into 4-Aminophenol