Abstract A simple and efficient functionalized graphene (f-graphene) doped chitosan (CS) based electrochemical aptasensor has been developed for ochratoxin A (OTA) detection. Use of f-graphene increased the electroactive surface area of the electrode and CS prevented leaching of the aptamer (APT) molecules. The dual properties of CS and f-graphene overall improved the sensor performance. The developed APT/SA/CS-f-graphene sensor has been characterized using Fourier Transform Infrared Spectroscopy (FTIR), Contact angle, Field emission - scanning electron microscopy (FE-SEM) and electrochemical studies. The aptasensor displayed OTA limit of detection (LOD) about 1 fg/mL for standard and 0.01 ng/mL for spiked sample within response time of 8 min. The reusable aptaelectrode retained 85% of initial current values after 7th reaction with stability of about 7 days. Besides, real application of the fabricated aptasensor has been evaluated in the grape juice samples. Recoveries of OTA in the range of 90–101% were estimated successfully.

中文翻译：

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基于石墨烯掺杂壳聚糖纳米复合材料的电化学适体传感器测定赭曲霉毒素A

摘要 开发了一种简单高效的功能化石墨烯 (f-graphene) 掺杂壳聚糖 (CS) 电化学适体传感器，用于赭曲霉毒素 A (OTA) 检测。f-石墨烯的使用增加了电极的电活性表面积，并且 CS 防止了适体 (APT) 分子的浸出。CS和f-石墨烯的双重特性总体上提高了传感器性能。开发的 APT/SA/CS-f-石墨烯传感器已使用傅立叶变换红外光谱 (FTIR)、接触角、场发射 - 扫描电子显微镜 (FE-SEM) 和电化学研究进行表征。在 8 分钟的响应时间内，适体传感器显示标准品的 OTA 检测限 (LOD) 约为 1 fg/mL，加标样品的 OTA 检测限为 0.01 ng/mL。可重复使用的适体电极在第 7 次反应后保留了 85% 的初始电流值，稳定性约为 7 天。此外，已经在葡萄汁样品中评估了制造的适体传感器的实际应用。成功估计了 90-101% 范围内的 OTA 回收率。