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Updated: Jun 14, 2026
Engineering Molecular Recognition with Bio-mimetic Polymers on Single Walled Carbon Nanotubes
Published on: January 10, 2017
Readily reusable electrochemical DNA hybridization biosensor based on the interaction of DNA with single-walled
Xuzhi Zhang1, Kui Jiao, Shufeng Liu
1Key Laboratory of Eco-Chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, People's Republic of China.
Abstract:
Carboxylic group-functionalized single-walled carbon nanotubes (SWNTs) were assembled vertically on the glassy carbon electrode using ethylenediamine as linking agent to fabricate an aligned electrode (SWNTE). Single-stranded DNA (ssDNA) wrapped around the SWNTs to form ssDNA-wrapped SWNTE structures based on the interaction between ssDNA and SWNT. A sensitive differential pulse voltammetric (DPV) response was obtained at the ssDNA-wrapped SWNTE owing to the electrooxidation of guanine bases. Double-stranded DNA (dsDNA) was formed when ssDNA on the ssDNA-wrapped SWNTE was hybridized with complementary ssDNA (cDNA). The dsDNA was removed from the SWNTs by undergoing a process of preconditioning at -0.6 V. Consequentially, the DPV response of guanine bases decreased. The used SWNTE could be renewed easily via ultrasonically rinsing. On the basis of this mechanism, a label-free and readily reusable electrochemical DNA hybridization biosensor was designed by directly monitoring the current change of guanine bases. Under optimum conditions, the plot of the measurement signal of guanine bases versus the cDNA concentrations was a good straight line in the range of 40-110 nM with a detection limit of 20 nM (3s). The biosensor can be switched to detect different target DNAs easily.
