Review of Graphene, Graphene Oxide, and Graphene Quantum Dot Nanomaterials-Based Pharmaceutical Drug Sensors

Pharmaceutical drug sensing is critical for therapeutic drug monitoring, precision dosing, and environmental safety. Conventional analytical platforms, such as high-performance liquid chromatography and mass spectrometry, deliver high accuracy but are constrained by instrument cost, labor-intensive workflows, and limited real-time applicability. Graphene and its derivatives nanomaterials, specifically graphene oxide (GO) and graphene quantum dots (GQDs), have emerged as versatile nanostructured transducers that bridge these gaps through their nanoscale features: exceptional electron mobility, high specific surface area, tunable surface chemistry, and rich edge/defect states. These properties enable sensitive interactions with drug molecules via π–π stacking, hydrogen bonding, redox mediation, and photoluminescence modulation. This review critically surveys recent advances in electrochemical, optical, and photoelectrochemical (PEC) sensing across major drug categories. We examine how material choice, hierarchical nanocomposites (e.g., metal oxides, metal–organic frameworks (MOFs), MXenes), and molecular recognition elements collectively govern detection limits spanning micromolar to femtomolar regimes. Comparative analysis distinguishes graphene as a conductive backbone, GO as a chemically addressable functional platform, and GQDs as quantum-confined photonic probes. The evolution of sensor design reveals clear trajectories toward higher selectivity, reduced fouling, and clinically relevant dynamic ranges. By consolidating structure–function–performance relationships, this review provides a translational framework for engineering next-generation graphene-derived sensors toward scalable, selective, and clinically deployable pharmaceutical monitoring platforms.