Graphene Quantum Dots in Biomedical Applications

Graphene quantum dots (GQDs) are atomically thin, quasi-zero-dimensional fragments of graphene with lateral dimensions below 10 nm. Their unique combination of tunable bandgap, intense and stable photoluminescence, high water solubility and large specific surface area has positioned them at the forefront of nanomedicine. Surface functional groups and facile chemical modification permit conjugation of targeting ligands, drugs or imaging agents, while maintaining low cytotoxicity and excellent biocompatibility. GQDs can traverse biological barriers, including the blood–brain barrier, and preferentially accumulate in cellular compartments such as the nucleus or tumour microenvironment. Key biomedical applications include fluorescence-based bioimaging, dual- or multi-modal diagnostic probes, pH and redox sensing, photodynamic and photothermal therapy through reactive oxygen species generation, as well as versatile drug-delivery platforms exploiting enhanced permeability and retention. Various top-down and bottom-up synthetic methods—ranging from oxidative exfoliation of graphite oxide to microwave-assisted carbonization of organic precursors—allow control over size, surface chemistry and optical properties. Recent advances underline the global potential of GQDs in precision medicine, from targeted anticancer strategies to neurotherapeutics and regenerative engineering.

Research from Nature Portfolio

Recent studies have engineered amine-functionalized GQDs to achieve selective nucleus targeting and potent anticancer efficacy. By grafting cell-penetrating peptides and folic-acid-modified polyethylene glycol, the resulting constructs demonstrated preferential uptake by cancer cells, adsorption onto genomic DNA via π–π and electrostatic interactions, induction of double-strand breaks and activation of apoptotic pathways, yielding significant tumour suppression with minimal off-target toxicity. Another investigation has elucidated how the oxidation state of GQD surfaces governs noncovalent adsorption of biopolymers such as single-stranded DNA. By preparing a series of GQDs spanning low to high oxidation levels, researchers showed that minimal oxidation favors strong polymer binding and fluorescence quenching—insights that inform the rational design of reversible biosensors and delivery vehicles without permanent covalent modification.

Graphene Quantum Dots in Biomedical Applications publication trend

The graph below shows the total number of articles in graphene quantum dots in biomedical applications across all publications each year (not limited to Nature Index journals).

Technical terms

Graphene quantum dot (GQD): A nanoscale fragment of graphene (typically <10 nm) exhibiting quantum confinement and edge effects that confer adjustable electronic and optical properties.

Photoluminescence: Emission of light following optical excitation, a hallmark of GQDs used for fluorescence imaging and sensing.

Enhanced permeability and retention (EPR) effect: The tendency of nanoscale carriers to accumulate in tumour tissue due to leaky vasculature and poor lymphatic drainage.

π–π stacking: Noncovalent interactions between aromatic systems, exploited for adsorption of drugs or biomolecules onto GQD surfaces.

References

1. Biocompatible nucleus-targeted graphene quantum dots for selective killing of cancer cells via DNA damage. Communications Biology (2021).
2. Graphene Quantum Dot Oxidation Governs Noncovalent Biopolymer Adsorption. Scientific Reports (2020).
3. Synthesis of graphene quantum dots and their applications in drug delivery. Journal of Nanobiotechnology (2020).
4. Bioactive Graphene Quantum Dots Based Polymer Composite for Biomedical Applications. Polymers (2022).