Pan Mengqi, Wang Zhen, Dai Yuxin, Yuan Ruo, Wang Haijun
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, Chongqing Engineering Laboratory of Nanomaterials & Sensor Technologies, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
Anal Chem. 2024 Sep 16. doi: 10.1021/acs.analchem.4c03347.
Herein, CuS colloidal nanocrystals (NCs) with adjustable band gap and good film forming ability have been synthesized as new ECL materials. Furthermore, the band gap and oxygen vacancy (O) content of CuS NCs are regulated by Al doping, which significantly improves the ECL response of CuS NCs. First, the band gap of CuS-Al NCs decreases after doping with Al, which makes it easier for electrons to transition across the band gap. At the same time, the oxygen vacancy of CuS-Al NCs increases, which is conducive to improving the conductivity and promoting charge transfer, thus improving the ECL performance of CuS-Al NCs. Circulating tumor DNA (ctDNA) is an important tumor marker, and its sensitive monitoring is of great significance for tumor diagnosis, treatment, and prognosis detection. Therefore, an ECL biosensor for ultrasensitive detection of circulating tumor DNA (ctDNA) was prepared by using CuS-Al NCs as luminescent material and combining multiple antidromic hybrid chain reaction (anti-HCR) strategy mediated by the target. Compared with the process of target-induced HCR generation, this strategy first forms multiple HCR products and then destroys the already formed HCR products by target-induced destruction, which enhances the sensitivity of target response and improves the reaction efficiency. The constructed biosensor has good detection performance, and the detection limit is as low as 2.74 aM. This work puts forward the luminescence phenomenon of colloidal nanocrystals as new ECL materials, which broadens the application of ECL technology in ultrasensitive biochemical detection.
在此，合成了具有可调带隙和良好成膜能力的硫化铜胶体纳米晶体（NCs）作为新型电化学发光（ECL）材料。此外，通过铝掺杂调节了硫化铜NCs的带隙和氧空位（O）含量，这显著提高了硫化铜NCs的ECL响应。首先，硫化铜-铝NCs掺杂铝后带隙减小，这使得电子更容易跨越带隙跃迁。同时，硫化铜-铝NCs的氧空位增加，这有利于提高导电性并促进电荷转移，从而提高了硫化铜-铝NCs的ECL性能。循环肿瘤DNA（ctDNA）是一种重要的肿瘤标志物，其灵敏监测对于肿瘤诊断、治疗和预后检测具有重要意义。因此，以硫化铜-铝NCs为发光材料，结合由靶标介导的多重反向杂交链式反应（anti-HCR）策略，制备了一种用于超灵敏检测循环肿瘤DNA（ctDNA）的ECL生物传感器。与靶标诱导的HCR生成过程相比，该策略先形成多个HCR产物，然后通过靶标诱导破坏已形成的HCR产物，增强了靶标响应的灵敏度并提高了反应效率。构建的生物传感器具有良好的检测性能，检测限低至2.74 aM。这项工作提出了胶体纳米晶体作为新型ECL材料的发光现象，拓宽了ECL技术在超灵敏生化检测中的应用。
