Direct Detection of DNA below ppb Level Based on Thionin-Functionalized Layered MoS2 Electrochemical Sensors

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• 作者：Tanyuan Wang ; Ruizhi Zhu ; Junqiao Zhuo ; Zhiwei Zhu ; Yuanhua Shao ; Meixian Li
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：December 16, 2014
• 年：2014
• 卷：86
• 期：24
• 页码：12064-12069
• 全文大小：399K
• ISSN：1520-6882

文摘

A layered MoS₂鈥搕hionin composite was prepared by sonicating their mixture in an ionic liquid and gradient centrifugation. Because DNA is rarely present in single-stranded form, either naturally or after PCR amplification, the composite was used for fabrication of a double-stranded DNA (dsDNA) electrochemical biosensor due to stable electrochemical response, intercalation, and electrostatic interaction of thionin with DNA. The linear range over dsDNA concentration from 0.09 ng mL^鈥? to 1.9 ng mL^鈥? is obtained, and moreover, it is suitable for the detection of single-stranded DNA (ssDNA). The biosensor has been applied to the detection of circulating DNA from healthy human serum, and satisfactory results have been obtained. The constructed DNA electrochemical biosensor shows potential application in the fields of bioanalysis and clinic diagnosis. Furthermore, this work proposes a new method to construct electrochemical biosensors based on MoS₂ sheets.