Size Characterization of Graphene‐coated Silver Nanoparticles for Drug Delivery System Design

Abstract

Nanoparticles prove to be a promising tool for drug delivery due to their modifiable properties, such as size, which may offer more targeted delivery. Silver nanoparticles (AgNPs) have been shown to exert anticancer effects such as antiangiogenesis. Size control is crucial for the use of AgNPs as drug delivery systems because smaller AgNPs amplify cytotoxicity in both cancerous and healthy cells. Another way that AgNPs are cytotoxic is through the release of silver (Ag+) ions. It has been shown that AgNPs below 10 nm in size have a comparable toxicity to Ag+ ions. In this study, AgNPs were coated with graphene quantum dots. Graphene quantum dots (GQDs) are nanosheets of carbon. These nanosheets of carbon may control the release of silver ions and provide additional benefits such as increased surface area for drug loading and increased drug solubility. The objective of this study is to synthesize graphene quantum dot‐coated silver nanoparticles (AgGQDs) to serve as drug delivery systems. We hypothesize that our methods will produce AgGQDs larger than 10 nm to avoid excessive cytotoxicity. The GQDs were synthesized by pyrolysis of citric acid and used as reducing agents for the synthesis of AgGQDs. The GQDs were characterized using X‐ray Photoelectron Spectroscopy (XPS). The AgGQDs were characterized via Transmission Electron Microscopy (TEM) and in situ Energy‐dispersive X‐ray Spectroscopy (EDS). EDS confirmed that the images observed were silver nanoparticles. TEM images showed that the AgGQDs were spherical and had a size of approximately 20‐25 nm in diameter. Based on these results, we can conclude that our AgGQDs will not be drastically cytotoxic due to their intermediate size.