Deng Kai, Zhang Yining, Xiao Hang, Hou Yujiao, Xu Qingbin, Li Ying, Kong Weijun, Ma Li
School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China.
Laboratory for Clinical Medicine, Capital Medical University, Beijing 100069, China.
ACS Omega. 2024 Feb 13;9(8):8754-8762. doi: 10.1021/acsomega.3c04619. eCollection 2024 Feb 27.
The ubiquitous aflatoxin B (AFB) contamination in foods and other complex matrices has brought great challenges for onsite monitoring. In this study, an ultrasensitive Nafion-immobilized functionalized multiwalled carbon nanotube (MWCNT)-based electrochemical (EC) immunosensor was developed for trace AFB detection. The introduced Nafion film could steadily stabilize functionalized MWCNTs with uniform distribution and tiling on the surface of a Au electrode. Functionalized MWCNTs with a large specific surface area, numerous active sites to couple with abundant anti-AFB monoclonal antibodies (mAbs), and high conductivity served as the signal amplifier for remarkably enhancing the sensing performance of the immunosensor. In the presence of AFB, it was specifically captured by mAbs to reduce the amplified current signals, which were recorded by differential pulse voltammetry for the accurate quantitation of AFB. Because of the synergistic effects of Nafion on the stabilization of functionalized MWCNTs as signal enhancers, the developed EC immunosensor exhibited an extremely high selectivity, excellent sensitivity with a limit of detection as low as 0.021 ng/mL, and a wide dynamic range of 0.05-100 ng/mL, besides fascinating merits of easy construction, low cost, good stability in 7 days, and good reusability. The anti-interference ability of the immunosensor was verified against three other mycotoxins, and the practicability and accuracy were confirmed by measuring AFB in fortified malt, lotus seed, and hirudo samples with a satisfactory recovery of 92.08-104.62%. This novel immunosensing platform could be extended to detect more mycotoxins in complex matrices to ensure food safety.
食品及其他复杂基质中普遍存在的黄曲霉毒素B（AFB）污染给现场监测带来了巨大挑战。在本研究中，开发了一种基于超灵敏的固定有Nafion的功能化多壁碳纳米管（MWCNT）的电化学（EC）免疫传感器，用于痕量AFB检测。引入的Nafion膜可以稳定地固定功能化MWCNT，使其均匀分布并平铺在金电极表面。功能化MWCNT具有大的比表面积、众多可与丰富抗AFB单克隆抗体（mAb）偶联的活性位点以及高导电性，作为信号放大器显著增强了免疫传感器的传感性能。在AFB存在的情况下，它被mAb特异性捕获，从而降低放大的电流信号，通过差分脉冲伏安法记录该信号以准确定量AFB。由于Nafion对功能化MWCNT作为信号增强剂的稳定作用具有协同效应，所开发的EC免疫传感器表现出极高的选择性、优异的灵敏度，检测限低至0.021 ng/mL，宽动态范围为0.05 - 100 ng/mL，此外还具有易于构建、成本低、7天内稳定性好以及良好的可重复使用性等优点。验证了该免疫传感器对其他三种霉菌毒素的抗干扰能力，并通过测定强化麦芽、莲子和水蛭样本中的AFB证实了其实用性和准确性，回收率令人满意，为92.08 - 104.62%。这种新型免疫传感平台可扩展用于检测复杂基质中的更多霉菌毒素，以确保食品安全。
