Design of an electrochemical DNA-based biosensor for selective determination of cadmium ions using a DNA hybridization indicator
2018
Ebrahimi, Maryam | Raoof, Jahan Bakhsh | Ojani, Reza
A simple electrochemical DNA- based biosensor was designed for determination of Cd²⁺ using ethyl green (EG) as a DNA hybridization indicator on the surface of carbon paste electrode (CPE). The interaction of Cd²⁺ with double strand DNA (dsDNA) led to the destabilizing of dsDNA and the increase in the reduction peak currents of EG. The difference in the values of electrochemical responses of EG before and after DNA helix destabilization in the presence of Cd²⁺ (ΔI) was used for Cd²⁺ determination and was linearly related to the concentration of Cd²⁺ over the ranges of 1.0pM–1.0nM and 10.0nM–1.0μM. Detection limit was achieved as low as 0.3pM using simple and low cost working electrode and without applying any materials for modification of electrode or DNA. The proposed biosensor was utilized successfully to real sample analysis of Cd²⁺.
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