Graphene Quantum Dots: Synthesis, Properties, and Applications in Electroanalysis

Graphene quantum dots (GQDs) are zero-dimensional carbon nanomaterials that integrate the π-conjugated structure of graphene with size-dependent and quantum-confined optical properties. Owing to their tunable electronic band gaps, excellent electrical conductivity, chemical versatility, and good biocompatibility, GQDs have emerged as promising materials for electroanalytical applications. This review summarizes recent advances in the synthesis, properties, modifications, and electroanalytical applications of GQDs, with an emphasis on the structure–function relationships of GQDs in electrochemical, electrochemiluminescence (ECL), and photoelectrochemical (PEC) sensing systems, thereby providing useful insights into future research directions in this field.