A highly parallel DTT/MB-DNA/Au electrochemical biosensor for trace Hg monitoring by using configuration occupation approach and SECM

Ecotoxicology and Environmental Safety

Yang Tang¹  Wei Gu²  Xinyue Li²  Jinping Li²  Meihua Yang³  Xuegang Guo³  Yonggui Ma⁴  Ming Sui⁵  Dandan Kong⁵  Gaofeng Wang⁵ 

[1] Corresponding authors.;Peking Union Medical College, Beijing 100193, PR China;Academy of Plateau Science and Sustainability, Qinghai Normal University / Key Laboratory of medicinal animal and plant resources of Qinghai Tibet Plateau, Xining, Qinghai 810008, PR China;Institute of Applied Electrochemistry, Beijing University of Chemical Technology, Beijing 100029, PR China;;Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences &

关键词: DTT/MB-DNA/Au;    Hg;    Steric-hinerance effect;    SECM;    Plants and medical products;   

DOI  :  

来源: DOAJ

【 摘 要 】

Environmental pollution and medicine safety have aroused increasing public concerns due to human health. Amongst various contaminants, mercury is of special attention owing to their environmental persistence and biogeochemical recycling and ecological risks. Herein, a simple and highly parallel electrochemical biosensor for Hg determination was designed and investigated. The proposed biosensor was prepared and compared between (1) DTT/MB-DNA/Au with configuration occupation approach and (2) MCH/MB-DNA/Au with passivation approach. According to the combined results of scanning electrochemical microscope (SECM) and Randles-Sevcik equation, the DTT modified electrode exhibited high uniformity on DNA distribution and superb stability on electron transfer in Hg2+ detection. Evidentially, the response value of proposed DTT/MB-DNA/Au was increased from 57.518% to 97.607%, while RSD% between duplicate runs had dropped from 22.658% to 0.223% (n = 3). Moreover, the increased proportion of effective working area was 467.380% compared with general sensors. Besides, DTT concentration, DNA concentration as well as assembly time were optimized, utilizing electrochemical impedance spectroscopy (EIS), Cyclic Voltammetry (CV) and Square Wave Anode Stripping Voltammetry (SWASV). This optimized biosensor exhibited an excellent selectivity toward Hg2+ over Cu2+, As2+, Cd2+, Pb2+, Cr3+, Ni2+ and Zn2+ etc., and the stability of DTT/MB-DNA/Au were at least two times better even after 3 days under room temperature. Also, a linear relation was observed between the peak current and Hg2+concentrations in a range from 0.25 nM to 2.00 μM with a detection limit of 53.00 pM under optimal conditions. Finally, DTT/MB-DNA/Au was applied for plants and medical products analysis. In all, this optimized DTT/MB-DNA/Au with advantages of high repeatability and sensitivity would provide a new insight into the design and application of biosensor for reliable sensing in safeguarding plant protection and medicinal safety.

【 授权许可】

Unknown