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.
Anal Chem. 2023 Sep 19;95(37):13897-13903. doi: 10.1021/acs.analchem.3c02201. Epub 2023 Sep 8.
Despite the fact that electrochemiluminescent (ECL) performance of carbon dots (CDs) could be improved by modulating their surface defects, they are still restricted by inferior controllability and poor reproducibility. In this work, we disclosed a new approach for synthesizing luminescent groups rich in CDs (Lu-CDs) by engineering the luminol as molecular emission centers into the CDs, which exhibited an 80-fold stronger ECL intensity at an ECL onset potential of 0.6 V than the CDs without pre-implanted luminol. Different from the significant deviation between the ECL and fluorescence emission of other surface state-dominated CDs, the ECL emission of Lu-CDs was nearly consistent with its fluorescence emission at 465 nm, which was defined as the molecular emission dominated-ECL CDs herein. To prove this principle, the Lu-CDs were employed to construct an ECL biosensor for MCF-7 cell analysis based on the cell direct recognition and amplification strategy, which made the MCF-7 cells as nanomachines specific binding with aptamer signal probes on the DNA triangular scaffold. The proposed biosensor displayed a wide detection range from 10 to 10 cell mL and a low detection limit of 8.91 cells mL. Overall, this work not only presents a new strategy for preparing CDs with high controllability and excellent reproducibility but also provides a platform for tumor cell sensing.
尽管通过调节碳点 (CDs) 的表面缺陷可以改善其电化学发光 (ECL) 性能，但它们仍然受到较差的可控性和较差的重现性的限制。在这项工作中，我们通过将发光分子鲁米诺设计为 CDs 中的分子发射中心，揭示了一种合成富含发光团的 CDs (Lu-CDs) 的新方法，与没有预先植入的鲁米诺的 CDs 相比，其在 0.6 V 的 ECL 起始电位下表现出 80 倍更强的 ECL 强度。与其他表面态主导的 CDs 的 ECL 和荧光发射之间存在显著偏差不同，Lu-CDs 的 ECL 发射与在 465nm 的荧光发射几乎一致，这被定义为本文中的分子发射主导-ECL CDs。为了证明这一原理，我们使用 Lu-CDs 构建了一种基于细胞直接识别和放大策略的 MCF-7 细胞分析 ECL 生物传感器，该策略使 MCF-7 细胞作为纳米机器，特异性结合 DNA 三角支架上的适体信号探针。所提出的生物传感器的检测范围从 10 到 10 细胞 mL ，检测限低至 8.91 细胞 mL。总体而言，这项工作不仅提出了一种制备具有高可控性和优异重现性的 CDs 的新策略，而且还为肿瘤细胞传感提供了一个平台。
