A rapid and simple electrochemical method was utilized for the determination of the presence of classic fungal metabolite ochratoxin A (OTA) based on differential pulse adsorptive voltammetry, using the carbon nanotube paste (CNTP) electrode. OTA showed a clear oxidation peak, and the CNTP electrode exhibited a more sensitive response to OTA oxidation than the glassy carbon, the plastic formed carbon, and the carbon paste electrodes. The addition of long‐chain cationic surfactants, such as benzethonium chloride, cetyltrimethylammonium bromide, and benzyldimethyltetradecylammonium chloride (zephiramine), enhanced the electrochemical response of OTA. Under optimized experimental conditions, the calibration plots are linear in the 5×10⁻⁶−5×10⁻⁵ M OTA concentration range, and the limit of detection is 1.1×10⁻⁶ M. In order to improve the selectivity for OTA determination, we attempted to combine this adsorptive stripping voltammetric technique with “sequestration electrochemistry,” based on the specific interaction occurring between bovine serum albumin (BSA) and OTA. The peak current of OTA oxidation decreased substantially as a result of OTA‐BSA binding. Furthermore, it was demonstrated that the application of this proposed method of hydrodynamic adsorptive voltammetry, using a micro‐droplet and a rotating disk electrode, improves the approach's sensitivity and reduces the time and sample volume required for the analysis.

中文翻译：

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阳离子表面活性剂富集吸附伏安法测定ch曲霉毒素A。

基于碳纳米管糊（CNTP）电极，基于差分脉冲吸附伏安法，使用一种快速，简单的电化学方法确定经典真菌代谢产物och曲霉毒素A（OTA）的存在。OTA显示出清晰的氧化峰，并且CNTP电极对OTA氧化的反应比玻璃碳，塑料形成的碳和碳糊电极更敏感。添加长链阳离子表面活性剂，例如苄索氯铵，十六烷基三甲基溴化铵和苄基二甲基十四烷基氯化铵（泽非拉明），可以增强OTA的电化学响应。在优化的实验条件下，校准图在5×10 ^-6 -5×10 ^-5内呈线性 M OTA浓度范围，检出限为1.1×10 ^-6M  。为提高OTA测定的选择性，我们尝试根据吸附脱附伏安技术与“螯合电化学”相结合的具体相互作用牛血清白蛋白（BSA）和OTA。由于OTA-BSA的结合，OTA氧化的峰值电流大大降低了。此外，事实证明，该拟议的水动力吸附伏安法的应用（使用微滴和旋转圆盘电极）可提高方法的灵敏度，并减少分析所需的时间和样品量。