Carbon Nanostructures in Biomedical Applications

Abstract

Carbon nanodots are quasi-spherical carbon materials with dimensions <10 nm (also termed zero-dimensional) and are endowed with several peculiar physiochemical features and attributes such as excellent biocompatibility and dispersibility,low cytotoxicity and cost, high stability, high photoluminescence and fluorescence, and easily tunable through surface modifications by addition of functional groups such as carboxyl (–COOH),hydroxyl (–OH), and amino (–NH ). This chapter summarizes the synthesis and diverse applications of carbon nanodots in the healthcare sector. The various strategies utilized for the synthesis of carbon nanodots in the recent past include topdown approaches such as arc-discharge, laser ablation, electrochemical approach, chemical exfoliation, and ultrasonic treatment; and bottomup approaches such as thermal pyrolysis,microwave heating, chemical vapor deposition, and template method. Further, the functionalization of the carbon nanodots for enhanced photochemical properties for varied applications in the clinical context is discussed. The functionalization is achieved through nanodot surface modification using different functional groups from polymers and ions and heteroatom doping using metals and non-metals. The tunable properties of carbon nanodots have brought a revolution in the health sector where these nanomaterials are finding applications in various bioimaging tools functioning on varied optical principles such as fluorescence,photoacoustic (optical luminance in combination with ultrasound detection) effect, and photothermal effect. The carbon nanodots have been used as antioxidants, antimicrobial agents, tumor detection and treatment, drug and gene delivery vehicle, and as biosensors. This is followed by a detailed account of the application of carbon nanodots in medicine and health care where the use of carbon nanodots