Grupo BIOeng, Escuela de Ingeniería Química, Universidad Técnica de Machala, Apartado 070151, Machala, Ecuador.
Departamento de Química, Universidad Simón Bolívar, Apartado 89000, Caracas, Venezuela.
Sensors (Basel). 2019 Feb 6;19(3):669. doi: 10.3390/s19030669.
We modified and evaluated the performance of a CuO/Cu electrochemical electrode for chemical oxygen demand (COD) determination by covering it with a Nafion (Nf) film. The resulting modified CuONf/Cu electrode sensor was used for the electrochemical determination of COD in river, slaughterhouse and estuarine water samples in order to evaluate its performance for this particular task. It was compared with the CuO/Cu sensor with no Nafion. The main electrochemical characteristics of interest, resistance, sensitivity, accuracy and reproducibility, were assessed by means of Linear Sweep Voltammetry using glucose as a standard. Results of these essays indicate that the procedure used produced smooth and firmly attached Nf films covering the whole copper surface. This sensor was shown to be resistant to interferences and effective in electro-oxidation of a wide range of organic compounds and therefore very useful for COD determination. Using the newly developed CuONf/Cu electrode an analytical linear range of 50 to 1000 mg·L COD, with a detection limit of 2.11 mg·L (n = 6) COD was achieved. The comparison shows that the CuONf/Cu sensor is more appropriate for COD determination than its counterpart with no Nafion.
我们通过覆盖 Nafion（Nf）膜来改进和评估氧化铜/铜电化学电极用于化学需氧量（COD）测定的性能。所得修饰的 CuONf/Cu 电极传感器用于河流、屠宰场和河口水样中 COD 的电化学测定，以评估其在该特定任务中的性能。它与没有 Nafion 的 CuO/Cu 传感器进行了比较。通过使用葡萄糖作为标准的线性扫描伏安法评估了感兴趣的主要电化学特性，包括电阻、灵敏度、准确性和重现性。这些论文的结果表明，所使用的方法产生了光滑且牢固附着的 Nf 膜，覆盖了整个铜表面。该传感器显示出对干扰的抵抗力和对广泛的有机化合物的有效电氧化能力，因此非常适用于 COD 测定。使用新开发的 CuONf/Cu 电极，实现了 50 至 1000mg·L COD 的分析线性范围，检测限为 2.11mg·L（n=6）COD。比较表明，CuONf/Cu 传感器比没有 Nafion 的传感器更适合 COD 测定。
