In this study, a signal-on electrochemiluminescence (ECL) aptasensor for ultrasensitive detection of sulfadimethoxine (SDM) was constructed based on a competitive aptamer strategy. Specifically, cerium-metal-organic framework (Ce-MOF) with large specific surface area and excellent electrical conductivity was combined with gold nanoparticles (AuNPs) to form a substrate, followed by the immobilisation of double-stranded DNA (dsDNA) via AuN bonds. In the presence of SDM, the aptamer tended to form an aptamer-SDM complex, which caused dsDNA to dissociate. After release of the aptamer, the capture probe (CP) combined with the tracer label to enhance the ECL signal. As expected, the prepared sensor displayed an ideal linear response range from 10.0 fg mL⁻¹ to 100 ng mL⁻¹ with a limit of detection (LOD) of 1.28 fg mL⁻¹ and successfully detected SDM in milk and quality control samples.

在本研究中，基于竞争性适体策略构建了一种用于超灵敏检测磺胺二甲氧嘧啶（SDM）的信号电化学发光（ECL）适体传感器。具体来说，将具有大比表面积和优异导电性的铈金属有机框架（Ce-MOF）与金纳米颗粒（AuNPs）结合形成基底，然后通过Au N固定双链DNA（dsDNA）债券。在 SDM 存在的情况下，适体倾向于形成适体-SDM 复合物，从而导致 dsDNA 解离。适配体释放后，捕获探针 (CP) 与示踪标记结合以增强 ECL 信号。^{正如预期的那样，所制备的传感器显示出从 10.0 fg mL -1}到 100 ng mL ^-1的理想线性响应范围，检测限 (LOD) 为 1.28 fg mL ^-1，并成功检测到牛奶和质量控制样品中的 SDM。