Development of novel and highly specific ssDNA-Aptamer-based electrochemical biosensor for rapid detection of Mercury (II) and Lead (II) ions in water

ABU-ALI, Hisham, NABOK, Alexei and SMITH, Thomas J. (2019). Development of novel and highly specific ssDNA-Aptamer-based electrochemical biosensor for rapid detection of Mercury (II) and Lead (II) ions in water. Chemosensors, 7 (2), e27.

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Abstract

In this work, we report on the development of an electrochemical biosensor for high selectivity and rapid detection of Hg2+ and Pb2+ ions using DNA-based specific aptamer probes labeled with ferrocene (or methylene blue) and thiol groups at their 5′ and 3′ termini, respectively. Aptamers were immobilized onto the surface of screen-printed gold electrodes via the SH (thiol) groups, and then cyclic voltammetry and impedance spectra measurements were performed in buffer solutions with the addition of HgCl2 and PbCl2 salts at different concentrations. Changes in 3D conformation of aptamers, caused by binding their respective targets, e.g., Hg2+ and Pb2+ ions, were accompanied by an increase in the electron transfer between the redox label and the electrode. Accordingly, the presence of the above ions can be detected electrochemically. The detection of Hg2+ and Pb2+ ions in a wide range of concentrations as low as 0.1 ng/mL (or 0.1 ppb) was achieved. The study of the kinetics of aptamer/heavy metal ions binding gave the values of the affinity constants of approximately 9.10−7 mol, which proved the high specificity of the aptamers used.

Item Type:	Article
Additional Information:	** From MDPI via Jisc Publications Router ** Licence for this article: https://creativecommons.org/licenses/by/4.0/ **Journal IDs: eissn 2227-9040 **History: published 04-06-2019; accepted 28-05-2019
Uncontrolled Keywords:	aptamer sensors, electrochemical sensors, heavy metal ions, cyclic voltammetry, impedance spectroscopy, binding kinetics
Identification Number:	https://doi.org/10.3390/chemosensors7020027
Page Range:	e27
SWORD Depositor:	Louise Beirne
Depositing User:	Louise Beirne
Date Deposited:	06 Jun 2019 08:16
Last Modified:	18 Mar 2021 05:12
URI:	https://shura.shu.ac.uk/id/eprint/24664

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