在这项研究中,我们报告了同时测定五种海洋毒素的多重平台.所提出的生物传感器基于由八个可单独寻址的碳电极组成的一次性电印刷(DEP)微阵列。金纳米颗粒在碳表面上的电沉积提供了高电导率并扩大了电活性面积。巯基化适体在AuNP修饰的碳电极上的固定提供了稳定的,良好的取向和组织的二元自组装单层,用于灵敏和准确的检测。设计了一种基于AuNP的简单电化学多路aptasensor,用于同步检测多种氰基毒素,即,微囊藻毒素-LR(MC-LR),圆柱精子素(CYL),Anatoxin-α,蛇床毒素和冈田酸(OA)。五种毒素的选择是基于它们的广泛存在和对水生生态系统和人类的毒性。利用适体在靶标结合时的构象变化,通过方波伏安法监测所产生的电子转移增加来实现氰毒素检测。在最优条件下,对于所有毒素,所提出的aptasensor的线性范围估计为0.018nM至200nM,除了MC-LR,在0.073至150nM的范围内检测是可能的。MC-LR的检出限为0.0033、0.0045、0.0034、0.0053和0.0048nM,具有出色的灵敏度,CYL,Anatoxin-α,毒素和OA,分别。进行选择性研究以显示五种分析物之间不存在交叉反应性。最后,将多重aptasensor应用于自来水样品显示出与缓冲液中获得的校准曲线非常好的一致性。这种简单而准确的多路复用平台可以为同时检测不同基质中的多种污染物打开窗口。
In this study, we report a multiplexed platform for the simultaneous determination of five marine toxins. The proposed biosensor is based on a disposable electrical printed (DEP) microarray composed of eight individually addressable carbon electrodes. The electrodeposition of gold nanoparticles on the carbon surface offers high conductivity and enlarges the electroactive area. The immobilization of thiolated aptamers on the AuNP-decorated carbon electrodes provides a stable, well-orientated and organized binary self-assembled monolayer for sensitive and accurate detection. A simple electrochemical multiplexed aptasensor based on AuNPs was designed to synchronously detect multiple cyanotoxins, namely, microcystin-LR (MC-LR), Cylindrospermopsin (CYL), anatoxin-α,
saxitoxin and okadaic acid (OA). The choice of the five toxins was based on their widespread presence and toxicity to aquatic ecosystems and humans. Taking advantage of the conformational change of the aptamers upon target binding, cyanotoxin detection was achieved by monitoring the resulting electron transfer increase by square-wave voltammetry. Under the optimal conditions, the linear range of the proposed aptasensor was estimated to be from 0.018 nM to 200 nM for all the toxins, except for MC-LR where detection was possible within the range of 0.073 to 150 nM. Excellent sensitivity was achieved with the limits of detection of 0.0033, 0.0045, 0.0034, 0.0053 and 0.0048 nM for MC-LR, CYL, anatoxin-α,
saxitoxin and OA, respectively. Selectivity studies were performed to show the absence of cross-reactivity between the five analytes. Finally, the application of the multiplexed aptasensor to tap water samples revealed very good agreement with the calibration curves obtained in buffer. This simple and accurate multiplexed platform could open the window for the simultaneous detection of multiple pollutants in different matrices.