Zhang Wancun, Zhang Pin, Liang Ying, Cheng Weyland, Li Lifeng, Wang Huanmin, Yu Zhidan, Liu Yan, Zhang Xianwei
Henan Key Laboratory of Children's Genetics and Metabolic Diseases, Zhengzhou Key Laboratory of Precise Diagnosis and Treatment of Children's Malignant Tumors, Children's Hospital Affiliated to Zhengzhou University Zhengzhou 450018 China
Department of Medicine, The First Affiliated Hospital of Zhengzhou University Zhengzhou China
RSC Adv. 2022 May 4;12(21):13448-13455. doi: 10.1039/d2ra01817a. eCollection 2022 Apr 28.
Rapid, simple, sensitive and specific approaches for mercury(ii) (Hg) detection are essential for toxicology assessment, environmental protection, food analysis and human health. In this study, a ratiometric hairpin DNA probe based electrochemical biosensor, which relies on hairpin DNA probes conjugated with water-soluble and carboxyl functionalized quaternary Zn-Ag-In-S quantum dot (QD) on screen-printed gold electrodes (SPGE), referred to as the HP-QDs-SPGE electrochemical biosensor in this study, was developed for Hg detection. Based on the "turn-off" reaction of a hairpin DNA probe binding with a mismatched target and Hg through the formation of T-Hg-T coordination, the HP-QDs-SPGE electrochemical biosensor can rapidly quantify trace Hg with high ultrasensitivity, specificity, repeatability and reproducibility. The conformational change of the hairpin DNA probe caused a significant decrease in electrochemical intensity, which could be used for the quantification of Hg. The linear dynamic range and high sensitivity of the HP-QDs-SPGE electrochemical biosensor for the detection of Hg was studied , with a broad linear dynamic range of 10 pM to 1 μM and detection limits of 0.11 pM. In particular, this HP-QDs-SPGE electrochemical biosensor showed excellent selectivity toward Hg ions in the presence of other metal ions. More importantly, this biosensor has been successfully used to detect Hg in deionized water, tap water, groundwater and urine samples with good recovery rate and small relative standard deviations. In summary, the developed HP-QDs-SPGE electrochemical biosensor exhibited promising potential for further applications in on-site analysis.
快速、简单、灵敏且特异的汞（II）（Hg）检测方法对于毒理学评估、环境保护、食品分析和人类健康至关重要。在本研究中，开发了一种基于比率型发夹DNA探针的电化学生物传感器，该传感器依赖于在丝网印刷金电极（SPGE）上与水溶性和羧基功能化的四元Zn-Ag-In-S量子点（QD）共轭的发夹DNA探针，在本研究中称为HP-QDs-SPGE电化学生物传感器，用于Hg检测。基于发夹DNA探针通过形成T-Hg-T配位与错配靶标和Hg结合的“关闭”反应，HP-QDs-SPGE电化学生物传感器能够以高灵敏度、特异性、重复性和再现性快速定量痕量Hg。发夹DNA探针的构象变化导致电化学强度显著降低，可用于Hg的定量。研究了HP-QDs-SPGE电化学生物传感器检测Hg的线性动态范围和高灵敏度，其线性动态范围为10 pM至1 μM，检测限为0.11 pM。特别是，该HP-QDs-SPGE电化学生物传感器在存在其他金属离子的情况下对Hg离子表现出优异的选择性。更重要的是，该生物传感器已成功用于检测去离子水、自来水、地下水和尿液样品中的Hg，回收率良好，相对标准偏差较小。总之，所开发的HP-QDs-SPGE电化学生物传感器在现场分析的进一步应用中显示出有前景的潜力。
