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A reagentless DNA‐based electrochemical silver(I) sensor for real time detection of Ag(I) – the effect of probe sequence and orientation on sensor response
Author(s) -
Wu Yao,
Lai Rebecca Y
Publication year - 2016
Publication title -
biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.144
H-Index - 84
eISSN - 1860-7314
pISSN - 1860-6768
DOI - 10.1002/biot.201500428
Subject(s) - cyclic voltammetry , linker , combinatorial chemistry , dna , electrochemistry , electrochemical gas sensor , chemistry , nanotechnology , thymine , materials science , analytical chemistry (journal) , electrode , chromatography , computer science , biochemistry , operating system
Ag(I) is known to interact with cytosine (C) via the formation C‐Ag(I)‐C complexes. The authors have utilized this concept to design six electrochemical Ag(I) sensors using C‐rich DNA probes. Alternating current voltammetry and cyclic voltammetry were used to analyze the sensors. The results show that the dual‐probe sensors that require the use of both 5'‐ and 3'‐thiolated DNA probes are not suitable for this application, the differences in probe orientation impedes formation of C‐Ag(I)‐C complexes. Sensors fabricated with DNA probes containing both thymine (T) and C, independent of the location of the alkanethiol linker, do not response to Ag(I) either; T‐T mismatches destabilize the duplex even in the presence of Ag(I). However, sensors fabricated with DNA probes containing both adenine (A) and C are ideal for this application, owing to the formation of C‐Ag(I)‐C complexes, as well as other lesser known interactions between A and Ag(I). Both sensors are sensitive, specific and selective enough to be used in 50% human saliva. They can also be used to detect silver sulfadiazine, a commonly prescribed antimicrobial drug. With further optimization, this sensing strategy may offer a promising approach for detection of Ag(I) in environmental and clinical samples.