基于CdTe量子点-壳聚糖-石墨烯纳米复合物构建亚硝酸盐电化学传感器

构建了一种基于CdTe量子点-壳聚糖-石墨烯纳米复合物修饰玻碳电极的亚硝酸盐电化学传感器,壳聚糖作为连接剂,CdTe量子点静电自组装负载到石墨烯上,外层包覆的聚乙烯吡咯烷酮(PVP)薄层用于稳定修饰物.对该传感器进行了电化学表征该电极,并与差分脉冲伏安法结合用于检测亚硝酸盐,该传感器在2 μmol/L~100 μmol/L范围内具有良好的线性关系,检出限为0.89 μmol/L,加标回收率在96.7%~101.8%内.该传感器具有灵敏度高、检出限低、准确、快速等优势,应用到市售腌菜中亚硝酸盐的检测,结果令人满意.

Electrochemical Nitrite Sensor Based on CdTe Quantum Dots-Chitosan-Graphene Nanocomposite modified glassy carbon electrode

A new sensitive and selective electrochemical nitrite sensor based on CdTe quantum dots-chitosan-graphene(Gr-CS-CdTe)nanocomposite modified glassy carbon electrode via electrostatic self-assembly strategy was fabricated.Herein,the negatively charged Gr dispersed in CS to form a stable film with the ability of enhancing electronic transport,simultaneously,the negative charged thioglycollic acid(TGA)capped CdTe QDs attached to positively charged CS,and polyvinyl pyrrolidone(PVP)was as the stabilizer coated on the outside layer.The sensor was characterized by its electrochemical behavior and it was showed that the oxidative peak of nitrite was largely enhanced and therefore the sensitively of the sensor was improved due to the very small size,high electron-transfer efficiency,large specific surface area of CdTe QDs.The proposed sensor combined with differential pulse voltammetry was applied in the determination of nitrite in pickled vegetable samples.The results showed that external standard calibration curve was linear in the range of 2 μmol/L~100 μmol/L with a detection limit of 0.89 μmol/L.The method was accurate with the recoveries ranged from 96.7 to 101.8%.