title: Single strand DNA functionalized single wall carbon nanotubes as sensitive electrochemical labels for arsenite detection.
abstract: In this work, a simple and sensitive electrochemical strategy for arsenite detection based on the ability of arsenite bound to single-strand DNA (ssDNA) and the signal transduction of single wall carbon nanotubes (SWCNTs) is developed. To realize this purpose, the ssDNA/SWCNTs complexes were formed at first by making ssDNA wrapped around SWCNTs via π-stacking. In the presence of arsenite, the arsenite could strongly bind with the G/T bases of ssDNA and decrease the π-π interaction between ssDNA and SWCNTs, resulting in a certain amount of ssDNA dissociating from the complexes. The separated SWCNTs were selectively assembled on the self-assembled monolayer (SAM) modified Au electrode. Then the SWCNTs onto the SAM-modified Au electrode substantially restored heterogeneous electron transfer that was almost totally blocked by the SAM. The assembled SWCNTs could generate a considerably sensitive and specific tactic for signal transduction, which was related to the concentration of the arsenite. Through detecting the currents mediated by SWCNTs, a linear response to concentration of arsenite ranging from 0.5 to 10ppb and a detection limit of 0.5ppb was readily achieved with desirable specificity and sensitivity. Such a SWCNTs-based biosensor creates a simple, sensitive, nonradioactive route for detection of arsenite. In addition, this demonstration provides a new approach to fabrication of stable biosensors with favorable electrochemical properties believed to be appealing to electroanalytical applications.
authors.affiliation: College of Life Science and Technology, Central South University of Forestry and Technology, 410004 Changsha, China; State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, 410082 Changsha, China. Electronic address: bionano@163.com.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Life Science and Technology, Central South University of Forestry and Technology, 410004 Changsha, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: College of Life Science and Technology, Central South University of Forestry and Technology, 410004 Changsha, China.
authors.forename: Yiqiang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, 410082 Changsha, China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: He
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, 410082 Changsha, China. Electronic address: kmwang@hnu.edu.cn.
authors.forename: Kemin
authors.initials: K
authors.lastname: Wang
mesh_terms: D018053:Arsenites / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D004277:DNA, Single-Stranded / Q000737:chemistry*; D060766:Drinking Water / Q000032:analysis*; D004563:Electrochemistry; D004566:Electrodes; D006801:Humans; D057230:Limit of Detection; D037742:Nanotubes, Carbon / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D018053:Arsenites; D004277:DNA, Single-Stranded; D060766:Drinking Water; D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical; C015001:arsenite
keywords: Arsenite; Biosensor; Electrochemical; SWCNTs; Signal transduction