Graphene quantum dots: emergent nanolights for bioimaging, sensors, catalysis and photovoltaic devices

Abstract

Similar to the popular older cousins, luminescent carbon dots (C-dots), graphene quantum dots or graphene quantum discs (GQDs) have generated enormous excitement because of their superiority in chemical inertness, biocompatibility and low toxicity. Besides, GQDs, consisting of a single atomic layer of nano-sized graphite, have the excellent performances of graphene, such as high surface area, large diameter and better surface grafting using π-π conjugation and surface groups. Because of the structure of graphene, GQDs have some other special physical properties. Therefore, studies on GQDs in aspects of chemistry, physical, materials, biology and interdisciplinary science have been in full flow in the past decade. In this Feature Article, recent developments in preparation of GQDs are discussed, focusing on the main two approaches (top-down and bottom-down). Emphasis is given to their future and potential development in bioimaging, electrochemical biosensors and catalysis, and specifically in photovoltaic devices that can solve increasingly serious energy problems.

Functionalized nanomaterials: their use as contrast agents in bioimaging: mono- and multimodal approaches

“…Besides, GQDs, consisting of a single atomic layer of nano-sized graphite, have the excellent performances of graphene, such as high surface area, large diameter, and better surface grafting using π -π conjugation and surface groups [158,159] .…”

Nanofabrication of Graphene Quantum Dots with High Toxicity Against Malaria Mosquitoes, Plasmodium falciparum and MCF-7 Cancer Cells: Impact on Predation of Non-target Tadpoles, Odonate Nymphs and Mosquito Fishes

“…We suspended grapheme oxide (1.0 g) in concentrated H 2 SO 4 for a period of 1-2 h in an ice-water bath and then treated them with 50 % (wt) KMnO 4 . The H 2 SO 4 conditions aid in shearing the graphene oxide.…”

“…For these reasons, GQD synthesized by various top-down and bottom-up approaches [2] are presently at the center of research efforts to develop low-toxicity, environmentally friendly alternatives to conventional semiconductor quantum dots [3,4].…”

Nanotubes Reinforcement of Degradable Polymers for Orthopedic Applications

“…[53][54][55] WSNTs have excellent mechanical properties (Young's modulus≈150GPa, bending modulus≈217GPa), The advantage of WSNTs in comparison to CNTs is that they possess functional groups, such as sulfide and oxy-sulfide, and can be readily dispersed in organic solvents, polymers, epoxy and resins. 56 Due to these potential benefits, the efficacy of WSNTs as fillers to improve the mechanical properties of biodegradable polymers used for bone tissue engineering needs to be investigated.…”