Graphene metal nanoclusters in cutting-edge theranostics nanomedicine applications

Abstract

The major breakthrough of graphene in 2004 has paved the way for various approaches to synthesize graphene and its derivatives for biomedical applications. With the interest in graphene as a cargo in drug delivery, the exploration has slowly shifted to metal-graphene materials as fluorescent probes. Metals such as Cu, Au, Fe, Ce and etc., have been incorporated into graphene for various applications such as sensing and imaging. With the success of graphene—metal nanoparticles (NPs), its more recently discovered counterpart, graphene—metal nanoclusters (NCs) has gained much interest lately. Loosely defined, NCs are a cluster of NPs with sizes of 1–20 nm with a narrow size distribution, which endows it with unique electronic properties compared to metal NPs. NCs are size-dependent fluorescent materials with good photostability. They have been largely investigated in biosensing, diagnosis and therapy applications, a term coined as theranostics. In more recent applications, graphene metal NCs were stabilized with protein biomarkers for targeted sensing of cancer cells and diseases. Smart delivery system allows diagnosis, imaging and targeted therapy simultaneously. This chapter focusses on the synthesis and biomedical applications of graphene—metal NCs with a detailed discussion on their properties and applications in the biomedical field. A brief description on the toxicity is addressed as well, together with future considerations for possible applications of graphene—metal NCs clinically.