A highly sensitive electrochemical sensor was developed through a one-pot green synthesis method for nitrite detection based on the electrochemical technique. Xylan-based carbon quantum dots (CQDs) were used as green in situ reducing agent to prepare CQDs capped gold nanoparticles (Au@CQDs). MXene of good electrical conductivity was used as the immobilized matrix to fabricate Au@CQDs-MXene nanocomposites with the advantages of good electrical conductivity and electrocatalysis. An electrochemical sensor for nitrite monitor was obtained by loading the Au@CQDs-MXene on a glassy carbon electrode. The sensor presents high sensitivity, good stability, wide linear range, and excellent selectivity due to the high catalytic activity of AuNPs and CQDs, the large specific surface area of MXene, and exceptional electrical conductivity of AuNPs and MXene. Under the optimal condition, the linear detection range of the sensor was from 1 μM to 3200 μM with a detection limit of 0.078 μM (S/N = 3), which was superior to most reported sensors using differential pulse voltammetry (DPV) method. Furthermore, this sensor was successfully applied to detect nitrite in tap water and salted vegetables with satisfactory recoveries. This modified electrocatalytic sensor shows a new pathway to fabricate nitrite detection sensor with feasibility for practical application.

基于电化学技术，通过一锅绿色合成法开发了一种高灵敏度的电化学传感器，用于亚硝酸盐的检测。基于木聚糖的碳量子点（CQDs）被用作绿色原位还原剂来制备 CQDs 封端的金纳米粒子（Au@CQDs）。以具有良好导电性和电催化性能的 MXene 为固定基体制备 Au@CQDs-MXene 纳米复合材料。通过将 Au@CQDs-MXene 负载在玻碳电极上，获得了用于亚硝酸盐监测的电化学传感器。由于AuNPs和CQDs的高催化活性、MXene的大比表面积以及AuNPs和MXene的优异导电性，该传感器具有高灵敏度、良好的稳定性、宽的线性范围和优异的选择性。在最佳条件下，传感器的线性检测范围为 1 μM 至 3200 μM，检测限为 0.078 μM（S/N = 3），优于大多数使用差分脉冲伏安法（DPV）方法报道的传感器。此外，该传感器已成功应用于检测自来水和盐渍蔬菜中的亚硝酸盐，回收率令人满意。这种改进的电催化传感器为制造具有实际应用可行性的亚硝酸盐检测传感器开辟了一条新途径。该传感器已成功应用于检测自来水和盐渍蔬菜中的亚硝酸盐，回收率令人满意。这种改进的电催化传感器为制造具有实际应用可行性的亚硝酸盐检测传感器开辟了一条新途径。该传感器已成功应用于检测自来水和盐渍蔬菜中的亚硝酸盐，回收率令人满意。这种改进的电催化传感器为制造具有实际应用可行性的亚硝酸盐检测传感器开辟了一条新途径。