3d.FAB, Université Lyon1, CNRS, INSA, CPE-Lyon, ICBMS, UMR 5246, 43, Bd du 11 november 1918, 69622, Villeurbanne cedex, France; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India; CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi, 110012, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India; CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi, 110012, India.
Talanta. 2021 Jan 15;222:121578. doi: 10.1016/j.talanta.2020.121578. Epub 2020 Aug 24.
This work reports the development of an electrical and optical biosensing for label-free detection of Aflatoxin B (AFB) using gold (Au) nanobipyramids (NBPs). AuNBPs were synthesized through a two-step seed-mediated growth process followed by an exchange of capping agent from surfactant to lipoic acid. Pure and monodispersed AuNBPs of 70 nm base length were obtained and deposited on indium tin oxide (ITO)-coated glass substrate modified with self-assembled (3-Aminopropyl) triethoxysilane (APTES) film. The characterization of the obtained surfaces using spectroscopy, microscopy and diffractometry confirms the formation of AuNBPs, the conjugation to ITO electrode substrate and the immobilization of anti-AFB antibodies. AuNBPs modified ITO substrates were used for both electrochemical and Surface Plasmon Resonance biosensing studies. Localized Surface Plasmon Resonance (LSPR) local field enhancement was demonstrated. SPR based AFB detection was found to be linear in the 0.1-500 nM range with a limit of detection of 0.4 nM, whereas, impedimetric AFB detection was shown to be linear in the 0.1-25 nM range with a limit of detection of 0.1 nM. The practical utility of the impedimetric sensor was tested in spiked maize samples and 95-100% recovery percentage was found together with low relative standard deviation, proof of the robustness of this AFB sensor.
本工作报道了一种基于金纳米棒（AuNBPs）的无标记电致化学发光和光学生物传感用于检测黄曲霉毒素 B（AFB）的方法。AuNBPs 通过两步种子介导生长法合成，然后通过表面活性剂到硫辛酸的配体交换来进行。得到了 70nm 基底长度的纯单分散 AuNBPs，并将其沉积在经过（3-氨丙基）三乙氧基硅烷（APTES）自组装修饰的氧化铟锡（ITO）涂层玻璃基底上。使用光谱学、显微镜和衍射仪对获得的表面进行的表征证实了 AuNBPs 的形成、与 ITO 电极基底的结合以及抗 AFB 抗体的固定化。AuNBPs 修饰的 ITO 基底用于电化学和表面等离子体共振（SPR）生物传感研究。证明了局部表面等离子体共振（LSPR）局域场增强。基于 SPR 的 AFB 检测在 0.1-500nM 范围内呈线性，检测限为 0.4nM，而基于阻抗的 AFB 检测在 0.1-25nM 范围内呈线性，检测限为 0.1nM。在经过 AFB 污染的玉米样品中测试了阻抗传感器的实际应用，发现回收率为 95-100%，相对标准偏差较低，证明了这种 AFB 传感器的稳健性。
