Molecular Science and Biomedicine Laboratory, State Key Laboratory for Chemo/Bio-Sensing and Chemometrics, College of Material Science and Engineering, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
Hunan Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China.
ACS Appl Mater Interfaces. 2024 Oct 23;16(42):56902-56909. doi: 10.1021/acsami.4c14358. Epub 2024 Oct 14.
This study constructed an electrochemiluminescence (ECL) biosensor for ultrasensitive detection of Pb in a ternary system by employing DNAzyme. The ternary system is composed of a potassium-neutralized perylene derivative (KPTC) as the ECL emitter, KSO as the coreactant, and neodymium metal-organic frameworks (Nd-MOFs) as the coreaction accelerators. Nd-MOFs immobilize DNAzymes and enhance the luminescence intensity of the KPTC/KSO system. As part of this system, KPTC enhances the ECL signal in solution and supports Pb detection. The sequence of ferrocene (Fc)-linked DNA (DNA-Fc) is catalytically cleaved by DNAzymes in the presence of Pb. This causes the removal of DNA1-Fc from the electrode surface to recover the ECL signal. As a result, the as-prepared ECL biosensor can quantify Pb with a detection limit (LOD) of 4.1 fM in the range of 1 μM to 10 fM. The ECL biosensor displays high specificity, good stability, excellent reproducibility, and desirable practicality for Pb detection in tap water. Moreover, by simply changing the sequence of the DNAzyme, new biosensors can be designed for ultrasensitive detection of different heavy metal ions, offering an excellent approach for monitoring water quality safety.
本研究构建了一种基于 DNA 酶的电化学发光（ECL）生物传感器，用于在三元体系中对 Pb 进行超灵敏检测。该三元体系由钾中和的苝衍生物（KPTC）作为 ECL 发射器、KSO 作为共反应物以及钕金属有机骨架（Nd-MOFs）作为共反应加速剂组成。Nd-MOFs 固定化 DNA 酶并增强 KPTC/KSO 体系的发光强度。在该体系中，KPTC 增强了溶液中的 ECL 信号，并支持 Pb 检测。在 Pb 存在的情况下，连接有二茂铁（Fc）的 DNA（DNA-Fc）序列被 DNA 酶催化切割。这导致 DNA1-Fc 从电极表面去除，从而恢复 ECL 信号。因此，所制备的 ECL 生物传感器可以在 1 μM 至 10 fM 的范围内定量检测 Pb，检测限（LOD）为 4.1 fM。ECL 生物传感器表现出高特异性、良好的稳定性、出色的重现性和良好的实际应用潜力，可用于检测自来水中的 Pb。此外，通过简单改变 DNA 酶的序列，可以设计用于检测不同重金属离子的新型生物传感器，为监测水质安全提供了一种优异的方法。
