Jarczewska M, Kierzkowska E, Ziółkowski R, Górski L, Malinowska E. Electrochemical oligonucleotide-based biosensor for the determination of lead ion.
Bioelectrochemistry 2014;
101:35-41. [PMID:
25042900 DOI:
10.1016/j.bioelechem.2014.06.013]
[Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 06/30/2014] [Accepted: 06/30/2014] [Indexed: 01/25/2023]
Abstract
The possibility of utilization of gold electrodes modified with short guanine-rich ssDNA probes for determination of Pb(2+) was examined. Interaction between guanine residues and lead ion followed by formation of G-quadruplex structures was confirmed by electrochemical impedance spectroscopy investigations. An external cationic redox label, methylene blue, was employed in voltammetric measurements for analytical signal generation. It was shown that due to the G-quadruplex formation, the oligonucleotides in the recognition layer fold, which enhances the electron transfer between methylene blue and the electrode surface. The MB current signal rises proportionally to the lead ion concentration in the range from 0.05 to 1μmol/L. The developed biosensor demonstrated high selectivity towards Pb(2+) ion, with only minor response towards interfering metal cations. The calculated limit of detection was of 34.7nmol/L. The utilization of the biosensor for Pb(2+) determination in real samples of water was also tested.
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