In this study, a thiol-modified aptamer was immobilized on a gold nanoparticle-modified molybdenum disulfide composite material (MoS₂@AuNPs), which could remove the interference of physical adsorption and reduce false positive signals. Furthermore, a non-fluorescent dual-thiol aptamer was immobilized on the surface of MoS₂@AuNPs with a low background signal. After attaching the cocaine using a dual-thiol aptamer immobilized on the surface of MoS₂@AuNPs, cocaine could be detected using a cocaine aptamer with 5-carboxyfluorescein (FAM). The aptamer–cocaine–aptamer complex was used to form a fluorescence signal, which made the signal noise (S/N) relatively high and sensitive to cocaine detection with 0.54 pM. Under optimal conditions, the change in the fluorescence intensity of the sensor was proportional to the concentration of cocaine in the range of 0–0.1 nM. This experiment was carried out in a human serum sample, and results showed that the analysis of cocaine using this sensor was promising.

中文翻译：

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适体-可卡因-适体法对可卡因的高灵敏度检测

在这项研究中，硫醇修饰的适体被固定在金纳米颗粒修饰的二硫化钼复合材料（MoS ₂ @AuNPs）上，可以消除物理吸附的干扰并减少假阳性信号。此外，非荧光双硫醇适体被固定在MoS ₂ @AuNPs的表面上，背景信号低。使用固定在MoS ₂表面的双硫醇适体附着可卡因后@AuNPs，可以使用可卡因适体与5-羧基荧光素（FAM）一起检测可卡因。适体-可卡因-适体复合物用于形成荧光信号，使信号噪声（S / N）相对较高，并且对0.54 pM的可卡因检测敏感。在最佳条件下，传感器荧光强度的变化与可卡因的浓度成正比，范围为0-0.1 nM。该实验是在人血清样本中进行的，结果表明，使用该传感器对可卡因进行分析很有希望。