Fluorescent graphene quantum dots: Properties regulation, sensing applications, and future prospects

Graphene quantum dots (GQDs), as an emerging class of nascent carbon-based materials, demonstrate remarkable promise in fluorescence sensing applications. Those potentials stem from several factors, including their favorable photoluminescence (PL) characteristics, feasibility of surface functionalization, excellent biocompatibility, and low cytotoxicity. This review concentrates on the fundamental optical properties of GQDs, with specific reference to the manipulation of intrinsic characteristics both by heteroatom doping and surface/edge functionalization. These modifications permit the alteration of optical properties, thereby rendering GQDs more versatile for an array of applications. Subsequently, we then delve into the recent applications of GQDs in fluorescence sensing, encompassing both turn-off and turn-on mechanisms. Finally, it presents a systematic assessment of the current state of research on GQDs, along with discussions on challenges and prospects for expanding and improving their applications.