AbstractAn electrochemical sensor for nitrite was fabricated by modifying a glassy carbon electrode (GCE) with the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) that is doped with carbon quantum dots (CQDs). The negatively charged CQDs were doped into PEDOT via electrodeposition to form a conducting polymer nanocomposite on the GCE. The electrode surface has a flake-like nanostructure and a large specific surface area. The elemental mapping analysis revealed that the CQDs are uniformly distributed across the whole nanocomposite. As a result of the superior catalytic activity of CQDs and the good conductivity of PEDOT, the modified GCE displays excellent electrocatalytic activity towards the oxidation of nitrite, and the oxidation peak current is ten times higher than that of a PEDOT modified GCE without CQDs. Under optimum conditions and at a working voltage of 0.80 V (vs. Ag/AgCl), the sensor has a linear response in the 0.5–1110 μM nitrite concentration range, and an 88 nM limit of detection (at S/N = 3). Three different electrodes prepared under the same experimental conditions were applied for the detection of nitrite, and the RSD was 3.1%. The same sensor was employed to quantify nitrite in three replicate measurements, and the RSD was 2.2%. Graphical abstractPoly(3,4-ethylenedioxythiophene) (PEDOT) was doped with carbon quantum dots and deposited on a glassy carbon electrode to obtain an amperometric sensor for nitrite.

中文翻译：

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用工程碳量子点掺杂的聚（3,4-亚乙基二氧噻吩）增强亚硝酸盐的电流检测

摘要 采用掺杂碳量子点（CQDs）的导电聚合物聚（3,4-乙撑二氧噻吩）（PEDOT）修饰玻碳电极（GCE），制备了亚硝酸盐电化学传感器。通过电沉积将带负电荷的 CQD 掺杂到 PEDOT 中，在 GCE 上形成导电聚合物纳米复合材料。电极表面呈片状纳米结构，比表面积大。元素映射分析表明 CQD 均匀分布在整个纳米复合材料中。由于CQDs优异的催化活性和PEDOT良好的导电性，改性GCE对亚硝酸盐的氧化表现出优异的电催化活性，氧化峰电流比没有CQDs的PEDOT改性GCE高10倍。在最佳条件和 0.80 V（相对于 Ag/AgCl）的工作电压下，传感器在 0.5–1110 μM 亚硝酸盐浓度范围内具有线性响应，检测限为 88 nM（S/N = 3） . 将在相同实验条件下制备的三种不同电极用于亚硝酸盐的检测，RSD为3.1%。使用相同的传感器在三个重复测量中定量亚硝酸盐，RSD 为 2.2%。图形摘要聚（3,4-亚乙基二氧噻吩）（PEDOT）掺杂碳量子点并沉积在玻碳电极上，以获得亚硝酸盐的电流传感器。将在相同实验条件下制备的三种不同电极用于亚硝酸盐的检测，RSD为3.1%。使用相同的传感器在三个重复测量中定量亚硝酸盐，RSD 为 2.2%。图形摘要聚（3,4-亚乙基二氧噻吩）（PEDOT）掺杂碳量子点并沉积在玻碳电极上，以获得亚硝酸盐的电流传感器。将在相同实验条件下制备的三种不同电极用于亚硝酸盐的检测，RSD为3.1%。使用相同的传感器在三个重复测量中定量亚硝酸盐，RSD 为 2.2%。图形摘要聚（3,4-亚乙基二氧噻吩）（PEDOT）掺杂碳量子点并沉积在玻碳电极上，以获得亚硝酸盐的电流传感器。