Hg2+ Electrochemical Biosensor Based on Target Triggered Exonuclease III-Assisted Dual Cycle Amplification and Tetrahedron DNA Nanostructures as Signal Molecule Carrier. Issue 6 (1st January 2019)

• Record Type: Journal Article
• Authors: Yuan, Yali; Liu, Guangpeng; Yang, Yang; Bai, Ying
• Is Part Of: Journal of the Electrochemical Society. Volume 166:Issue 6(2019)
• Page Start: B336
• Page End: B340
• Publication Date: 2019-01-01
• Subjects: Electroanalytical Electrochemistry -- Dual cycle -- Signal amplification -- Tetrahedron DNA; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0231906jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : A novel Hg 2+ electrochemical assay was presented based on target triggered exonuclease III (Exo III) assisted dual cycle amplification and tetrahedron DNA (TDNA) nanostructures as efficient signal molecules carrier. The thymine bases rich (T-rich) hairpin 1 (HP1) was wisely designed with the significant report DNA (RDNA) sequence in the loop, which could be acted as probes for specially recognizing Hg 2+ with formation of duplex-like structure through T-Hg 2+ -T coordination. This duplex-like structure could be digested by Exo III to release numerous Hg 2+ for next cycle, accompanying with the generation of an important digestion product RDNA for opening hairpin 2 (HP2) on electrode. After the introduction of hairpin 3 (HP3) on electrode via strand displacement reactions, the RDNA could be released again for next cycle, leading to the assembly of large amounts of HP3 for decorating TDNA. Finally, by using the TDNA as carriers for loading substantial signal probe thionine (Thi), a remarkable electrochemical signal could be acquired for quantitative detection of target. As a result, the developed biosensor showed a low detection limit of 33 fM for Hg 2+ determination. This strategy designed a novel electrochemical biosensor, which offered a new way for metal ion detection, showing potential applications in environmental monitoring.