A label-free photoelectrochemical aptasensor based on nitrogen-doped graphene quantum dots for chloramphenicol determination

作者：Liu, Yong; Yan, Kai; Okoth, Otieno Kevin; Zhang, Jingdong^*

来源：Biosensors and Bioelectronics, 2015, 74: 1016-1021.

DOI：10.1016/j.bios.2015.07.067

• Photoelectrochemical sensor
• Aptamer
• Nitrogen-doped graphene quantum dots
• Chloramphenicol

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 it-conjugated structure of N-GQDs provided an excellent platform for aptamer immobilization via pi-pi 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.

• 出版日期2015-12-15
• 单位华中科技大学