A label-free photoelectrochemical aptasensor based on nitrogen-doped graphene quantum dots for chloramphenicol determination
A photoelectrochemical (PEC) sensing platform for chloramphenicol (CAP) detection was constructed using nitrogen-doped graphene quantum dots (N-GQDs) as transducer species and label-free aptamer as biological recognition element . N-GQDs, synthesized via a facile one-step hydrothermal method , were explored to achieve highly efficient photon-to-electricity conversion under visible light irradiation . The obtained N-GQDs were characterized by transmission electron microscopy (TEM), which displayed a narrow size distribution with a mean diameter of 2.14 nm. The X-ray photoelectron spectroscopic (XPS) and Fourier transform infrared spectroscopic (FT-IR) analysis confirmed that nitrogen was successfully doped in GQDs. The UV–visible absorption spectra indicated that nitrogen doping obviously enhanced the absorption of GQDs in visible light region. As a result, the PEC activity of GQDs was promoted by nitrogen doping. Additionally, the π-conjugated structure of N-GQDs provided an excellent platform for aptamer immobilization via π–π stacking interaction. Such an aptamer/N-GQDs based sensor showed a linear PEC response to CAP concentration in the range of 10–250 nM with a detection limit (3 S/N) of 3.1 nM. The developed PEC aptasensor exhibited high sensitivity and selectivity , good reproducibility and high stability.
危险品化学品经营许可证（带存储）