AbstractThe authors describe a label-free electrochemical biosensor based on CNTs for picogram range detection of the food carcinogen aflatoxin B1 (AFB1). A gold electrode was modified with a cysteine (Cys) self-assembled layer, and carboxyl-functionalized carbon nanotubes were covalently attached to Cys for the subsequent tethering of antibody against AFB1 (anti-AFB1). Topographical images of the biosensor surface were acquired by atomic force microscopy throughout the modification and assay procedure. Upon exposure to samples containing AFB1, its binding to anti-AFB1 will result in a change in electrical conductivity. The use of CNT warrants enhanced electrical properties, and the charge-transfer resistance (Rct) can be related to the concentration of AFB1. Biosensor selectivity was tested by using samples containing ochratoxin A. The electrode displays a limit of detection as low as 0.79 pg·g−1, and response is linear in the 0.1 to 20 pg·g−1 concentration range. The assay was applied to the determination of AFB1 in contaminated corn flour at concentrations so low that they cannot be quantified by established ELISAs. In our perception, this method represents a viable point-of-care probe for detection of AFB1. Graphical abstractA gold electrode was modified with a cysteine self-assembled layer, and carboxyl-functionalized carbon nanotubes were covalently attached to cysteine for the subsequent tethering of antibody against AFB1. The assay was applied to the determination of AFB1 in contaminated corn flour.

中文翻译：

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使用具有共价固定碳纳米管的半胱氨酸修饰金电极对黄曲霉毒素 B1 进行免疫分析

摘要作者描述了一种基于 CNT 的无标记电化学生物传感器，用于食物致癌物质黄曲霉毒素 B1 (AFB1) 的皮克范围检测。金电极用半胱氨酸 (Cys) 自组装层修饰，羧基功能化的碳纳米管共价连接到 Cys，用于随后连接针对 AFB1 的抗体（抗 AFB1）。在整个修改和分析过程中，通过原子力显微镜获取生物传感器表面的形貌图像。暴露于含有 AFB1 的样品后，其与抗 AFB1 的结合将导致电导率发生变化。CNT 的使用保证了增强的电性能，并且电荷转移电阻 (Rct) 可能与 AFB1 的浓度有关。使用含有赭曲霉毒素 A 的样品测试生物传感器的选择性。该电极的检测限低至 0.79 pg·g-1，响应在 0.1 至 20 pg·g-1 浓度范围内呈线性。该测定用于测定受污染玉米粉中 AFB1 的浓度低到无法通过已建立的 ELISA 进行量化的程度。在我们看来，这种方法代表了一种用于检测 AFB1 的可行的护理点探针。图形摘要用半胱氨酸自组装层修饰金电极，羧基功能化的碳纳米管与半胱氨酸共价连接，用于随后连接针对 AFB1 的抗体。该方法用于测定受污染玉米粉中的AFB1。该测定法用于测定受污染玉米粉中 AFB1 的浓度低到无法通过已建立的 ELISA 进行量化的程度。在我们看来，这种方法代表了一种用于检测 AFB1 的可行的护理点探针。图形摘要用半胱氨酸自组装层修饰金电极，羧基功能化的碳纳米管与半胱氨酸共价连接，用于随后连接针对 AFB1 的抗体。该方法用于测定受污染玉米粉中的AFB1。该测定用于测定受污染玉米粉中 AFB1 的浓度低到无法通过已建立的 ELISA 进行量化的程度。在我们看来，这种方法代表了一种用于检测 AFB1 的可行的护理点探针。图形摘要用半胱氨酸自组装层修饰金电极，羧基功能化的碳纳米管与半胱氨酸共价连接，用于随后连接针对 AFB1 的抗体。该方法用于测定受污染玉米粉中的AFB1。和羧基功能化的碳纳米管与半胱氨酸共价连接，用于随后连接针对 AFB1 的抗体。该方法用于测定受污染玉米粉中的AFB1。和羧基功能化的碳纳米管与半胱氨酸共价连接，用于随后连接针对 AFB1 的抗体。该方法用于测定受污染玉米粉中的AFB1。