title: Electrochemical studies on the permeable characteristics of thiol-modified double-stranded DNA self-assembled monolayers on gold.
abstract: In this article we studied the permeable characteristics of thiol-modified double-stranded DNA (ds-DNA) self-assembled monolayers (SAMs) on a gold substrate assembled under different NaCl concentrations by electrochemical methods. It was based on the inspection of five important parameters including interfacial capacitance (C), phase angle (Φ(1 Hz)), ions transfer resistance (R(it)*), current density difference (Δj) and electron transfer rate (k(et)) through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Three sections were included: (1) Investigation of the relationships of C, Φ(1 Hz), R(it)*, Δj and k(et) with NaCl concentrations and comparison with the reports from literature. Experimental results showed that ds-DNA-SAMs were permeable films. (2) Construction of a simple model for exploring the permeable characteristics of ds-DNA-SAMs on gold. (3) Confirmation of the simple model by chronocoulometry (CC) and application of the model to explain the permeable mechanism. This study was significant for exploring the mechanism of electron transfer through the interior of ds-DNA duplex helix.
authors.affiliation: School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry, Nanjing University, China.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Li
authors.forename: Tianxing
authors.initials: T
authors.lastname: Niu
authors.forename: Zhenjiang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Ran
authors.initials: R
authors.lastname: Chen
authors.forename: Guiying
authors.initials: G
authors.lastname: Feng
authors.forename: Shuping
authors.initials: S
authors.lastname: Bi
mesh_terms: D004247:DNA / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D013438:Sulfhydryl Compounds; D012965:Sodium Chloride; D006046:Gold; D004247:DNA