AbstractA voltammetric analytical assay for the selective quantification of vanillin is described. It is based on the use of a gold nanoparticle-modified screen-printed carbon electrode (SPCE) modified with graphene quantum dots (GQD) in a Nafion matrix. The GQD were synthesized by an acidic thermal method and characterized by UV-Vis, photoluminescence, and FTIR spectroscopy. The modified SPCE displays a strongly enhanced response to vanillin. Linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV) were applied to optimize the methods. The analytical assay has linear responses in the 13 to 660 μM and 0.66 to 33 μM vanillin concentration ranges. The detection limits are 3.9 μM and 0.32 μM when using LSV and DPV, respectively. The analytical assay is selective and stable. It was applied to the determination of vanillin in several food samples with satisfactory results. Recoveries from spiked samples ranged between 92.1 and 113.0%. Graphical abstractThe selective and sensitive quantification of vanillin is carried out by the use of a gold nanoparticle-modified screen-printed carbon electrode modified with graphene quantum dots in a Nafion matrix.

中文翻译：

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石墨烯量子点和Nafion修饰的金纳米粒子修饰丝网印刷碳电极测定香兰素

摘要描述了用于选择性定量香草醛的伏安分析法。它基于在 Nafion 矩阵中使用石墨烯量子点 (GQD) 改性的金纳米粒子改性丝网印刷碳电极 (SPCE)。GQD 是通过酸性热法合成的，并通过 UV-Vis、光致发光和 FTIR 光谱进行表征。改良的 SPCE 显示出对香草醛的强烈反应。应用线性扫描伏安法 (LSV) 和差分脉冲伏安法 (DPV) 来优化方法。分析测定在 13 至 660 μM 和 0.66 至 33 μM 香草醛浓度范围内具有线性响应。使用 LSV 和 DPV 时，检测限分别为 3.9 μM 和 0.32 μM。分析测定具有选择性和稳定性。用于多种食品样品中香兰素的测定，结果令人满意。加标样品的回收率介于 92.1% 和 113.0% 之间。图形摘要香草醛的选择性和灵敏定量是通过使用在 Nafion 矩阵中用石墨烯量子点修饰的金纳米粒子修饰的丝网印刷碳电极进行的。