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.
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.
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DOI：
10.1002/biot.201500428
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发表时间：
2016-06
影响因子：
4.7
通讯作者：
Lai RY
中科院分区：
文献类型：
--
作者：
Wu Y;Lai RY
已知 Ag(I) 通过形成 C-Ag(I)-C 复合物与胞嘧啶 (C) 相互作用。在本研究中，我们利用这一概念设计了六种使用富含 C DNA 探针的电化学 Ag(I) 传感器。使用交流伏安法和循环伏安法来分析传感器。我们的结果表明，需要同时使用 5'- 和 3'- 硫醇化 DNA 探针的双探针传感器不适合该应用，探针方向的差异阻碍了 C-Ag(I)-C 复合物的形成。使用同时含有胸腺嘧啶 (T) 和 C 的 DNA 探针制造的传感器，无论烷硫醇接头的位置如何，也不会响应 Ag(I)；即使存在 Ag(I)，T-T 错配也会破坏双链体的稳定性。然而，由于 C-Ag(I)-C 复合物的形成以及 A 和 Ag(I) 之间其他鲜为人知的相互作用，使用同时含有腺嘌呤 (A) 和 C 的 DNA 探针制造的传感器非常适合此应用。这两种传感器都具有足够的灵敏度、特异性和选择性，可用于 50% 的人类唾液。它们还可用于检测磺胺嘧啶银（一种常用的抗菌药物）。通过进一步优化，这种传感策略可能为环境和临床样本中 Ag(I) 的检测提供一种有前途的方法。
Ag(I) is known to interact with cytosine (C) via the formation C-Ag(I)-C complexes. In this study we 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. Our 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.