Oztürk Funda Özcan, Erden Pınar Esra, Kaçar Ceren, Kiliç Esma
Acta Chim Slov. 2014;61(1):19-26.
An amperometric xanthine biosensor was developed based on the immobilization of xanthine oxidase (XO) into the Fe3O4 nanoparticles modified carbon paste. Electron transfer properties of unmodified and Fe3O4 nanoparticles modified carbon paste electrodes were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Fe3O4 nanoparticles increased electroactive surface area of the electrode and electron transfer at solution/electrode interface. Optimum pH, nanoparticle loading and enzyme loading were found to be 6.0; 14.2% and 0.6 Unit XO respectively. Fe3O4 nanoparticles modified carbon paste enzyme electrode allowed xanthine determination at -0.20 V, thus minimizing the potential interferences from electrochemically oxidizable substances such as ascorbic acid and uric acid. A linear relationship was obtained in the concentration range from 7.4 × 10-7 mol L-1 to 7.5 × 10-5 mol L-1 and a detection limit of 2.0 × 10-7 mol L-1. The biosensor was used for determination of xanthine in urine samples and the results indicate that the biosensor is effective for the detection of xanthine.
基于将黄嘌呤氧化酶（XO）固定到Fe3O4纳米颗粒修饰的碳糊中，开发了一种电流型黄嘌呤生物传感器。通过循环伏安法和电化学阻抗谱研究了未修饰的和Fe3O4纳米颗粒修饰的碳糊电极的电子转移特性。Fe3O4纳米颗粒增加了电极的电活性表面积以及溶液/电极界面处的电子转移。发现最佳pH值、纳米颗粒负载量和酶负载量分别为6.0；14.2%和0.6单位XO。Fe3O4纳米颗粒修饰的碳糊酶电极可在-0.20 V下测定黄嘌呤，从而将来自诸如抗坏血酸和尿酸等可电化学氧化物质的潜在干扰降至最低。在7.4×10-7 mol L-1至7.5×10-5 mol L-1的浓度范围内获得了线性关系，检测限为2.0×10-7 mol L-1。该生物传感器用于测定尿样中的黄嘌呤，结果表明该生物传感器对黄嘌呤的检测有效。
