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Energy level engineering of graphene–functional graphene quantum dot for highly sensitive and selective electrochemical detection of uric acid in human sweat
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DOI:10.1007/s00604-026-08335-6.png)
Abstract
En 中文
Pristine graphene lacks a bandgap, which prevents energy-selective electron transfer and results in a poor selectivity among analytes with similar oxidation potentials, along with high background currents. To address this intrinsic limitation, we hybridize graphene with quantum-confined graphene quantum dots (GQDs) to create an energy-level gating interface for electrochemical sensing. The mixture of citric acid, arginine, boric acid and phosphoric acid was heated at 180 °C and then protonated with hydrochloric acid, yielding a positively charged, arginine-functionalized B,P-co-doped GQD (RBP-GQD⁺). Dropwise addition of RBP-GQD⁺ to a graphene oxide dispersion drives rapid electrostatic self-assembly, followed by thermal reduction under N₂ to form a G/RBP-GQD composite. The composite exhibits enhanced electrocatalytic activity and selectivity from three synergistic effects: enlarged electroactive area, Schottky heterojunction formation, and energy-level gating interface. The catalytic behavior depends critically on GQD structure, which governs energy-level alignment and thus selectivity. Using this platform, an electrochemical sensor for uric acid achieves linear range of 0.1–200 µM, a detection limit of 0.031 µM, and reliable operation in human sweat. More generally, this work establishes a mesoscopic electronic-state engineering strategy that extends to other zero-bandgap materials through functionalization with tailored quantum dots—opening avenues for catalysis, diagnostics, and environmental sensing.
Keywords:
Graphene
Graphene quantum dot
Uric acid
Energy-level gating
Electrochemical sensor
Journal
M
IF:
5.3
Papers:
9.3K
Citations:
2.3W
