Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
Department of Endocrinology, 9 th People's Hospital of Chongqing, Chongqing, 400700, PR China.
Biosens Bioelectron. 2023 Nov 15;240:115607. doi: 10.1016/j.bios.2023.115607. Epub 2023 Aug 16.
In this work, selenium and nitrogen co-doped carbon dots (SeN-CDs) possessing highly efficient electrochemiluminescence (ECL) and excellent biocompatibility were synthesized as a new emitter with SO as a coreactant for constructing a biosensor to detect microRNA-221 (miRNA-221) sensitively. Notably, the SeN-CDs exhibited superior ECL performance compared with the N-doped CDs, in which selenium with excellent redox activity served as a coreaction accelerator for facilitating the electroreduction of SO to significantly improve ECL efficiency. Furthermore, target-induced T7 exonuclease (T7 Exo)-assisted double cycle amplification strategy could convert traces of target miRNA-221 into large amounts of output DNA to capture three-dimensional (3D) nanostructures (DTN-Au NPs-DOX-Fc) loaded with large amounts of ECL signal quencher. The constructed biosensor could realize ultrasensitive detection of miRNA-221 and has a low detection limit reaching 2.3 aM, with a successful application to detect miRNA-221 in lysate of Hela and MHCC97-L cancer cell. This work explored a novel method to strengthen the ECL performance of CDs to construct an ECL biosensing platform with sensitive detecting of biomarkers and disease diagnosis.
在这项工作中，合成了具有高效电致化学发光（ECL）和良好生物相容性的硒和氮共掺杂碳点（SeN-CDs），并将其作为一种新型发射器，以 SO 作为共反应物，构建了一种用于灵敏检测 microRNA-221（miRNA-221）的生物传感器。值得注意的是，与 N 掺杂的 CDs 相比，SeN-CDs 表现出了更优异的 ECL 性能，其中具有优异氧化还原活性的硒可作为共反应加速剂，促进 SO 的电还原，从而显著提高 ECL 效率。此外，目标诱导的 T7 外切酶（T7 Exo）辅助的双循环扩增策略可将痕量的目标 miRNA-221 转化为大量的输出 DNA，从而捕获大量 ECL 信号猝灭剂负载的三维（3D）纳米结构（DTN-Au NPs-DOX-Fc）。所构建的生物传感器可实现对 miRNA-221 的超灵敏检测，检测限低至 2.3 aM，并成功应用于检测 Hela 和 MHCC97-L 癌细胞裂解液中的 miRNA-221。本工作探索了一种新方法来增强 CDs 的 ECL 性能，构建了一个具有生物标志物灵敏检测和疾病诊断功能的 ECL 生物传感平台。
