Biosensor National Special Laboratory, Key Laboratory of Biomedical Engineering of Ministry of Education, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, China.
Innovation Center for Smart Medical Technologies & Devices, Binjiang Institute of Zhejiang University, Hangzhou, 310053, China.
Analyst. 2022 Nov 21;147(23):5314-5323. doi: 10.1039/d2an01394k.
PbTx-2 and okadaic acid (OA) are two typical marine toxins that are highly toxic and harmful to human health. The approach based on citrate-capped gold nanoparticles (Cit-AuNPs) and specific aptamers to construct label-free colorimetric sensors is a widely used method for marine toxin detection. However, the potential interactions between Cit-AuNPs and target molecules have always been ignored, which may result in wrong analytical results due to shortcomings in the Cit-AuNPs. To overcome these shortfalls, in this work, AuNPs were synthesized using tyrosine as a reducing and capping agent, and a robust colorimetric aptasensor based on tyrosine-capped AuNPs (Tyr-AuNPs) was constructed for the label-free detection of marine toxins. Tyr-AuNPs presented better stability compared to Cit-AuNPs due to the stronger binding of amine groups on tyrosine to AuNPs through the Au-N bond. Interactions between Tyr-AuNPs and PbTx-2 were analyzed through UV-vis and isothermal titration calorimetry methods and the results validated the robustness of the Tyr-AuNPs. Colorimetric aptasensors were established for PbTx-2 and OA detection with a linear range of 0.05-4 ppm and limits of detection of 2.25 ppb and 5.19 ppb, respectively. These results demonstrate that the developed colorimetric aptasensor can be a robust and promising method for marine toxin detection.
PbTx-2 和 okadaic 酸（OA）是两种典型的海洋毒素，对人类健康具有高度毒性和危害性。基于柠檬酸包覆的金纳米粒子（Cit-AuNPs）和特定适配体构建无标记比色传感器的方法是一种广泛用于海洋毒素检测的方法。然而，Cit-AuNPs 与目标分子之间的潜在相互作用一直被忽视，这可能由于 Cit-AuNPs 的缺点而导致错误的分析结果。为了克服这些缺点，在这项工作中，使用酪氨酸作为还原剂和封端剂合成了 AuNPs，并构建了基于酪氨酸封端的 AuNPs（Tyr-AuNPs）的强大比色适体传感器，用于无标记检测海洋毒素。与 Cit-AuNPs 相比，Tyr-AuNPs 具有更好的稳定性，因为酪氨酸上的氨基通过 Au-N 键与 AuNPs 更强地结合。通过紫外-可见和等温滴定微量热法分析了 Tyr-AuNPs 与 PbTx-2 之间的相互作用，结果验证了 Tyr-AuNPs 的稳健性。建立了用于检测 PbTx-2 和 OA 的比色适体传感器，线性范围分别为 0.05-4 ppm，检测限分别为 2.25 ppb 和 5.19 ppb。这些结果表明，所开发的比色适体传感器可以成为一种强大且有前途的海洋毒素检测方法。
