Designing a novel DNA-based electrochemical biosensor to determine of Ba2+ ions both selectively and sensitively

Abstract

This work describes a novel electrochemical biosensor based on G-quadruplex (G4) DNA for the sensitive and selective detection of Ba²⁺ ions using a Carbon Paste Electrode modified with Ag nanoparticles incorporated in reduced Graphene Oxide via a simple wet chemical method (Ag-rGO/CPE), in the presence of carmoisine (CA) as a new electrochemical indicator. The peak current of CA increased with increasing Ba²⁺ ions concentration and the DNA-based sensor showed linear ranges of 0.06-0.80 nM and 1.0-80 nM and a Limit of Detection (LOD) of 0.045 nM. The proposed biosensor showed a good selectivity toward Ba²⁺ ions in the presence of other metal ions such as Ag⁺, Hg²⁺, K⁺ and Na⁺ and was applied to the analysis of natural samples showing appropriate results.

Keywords: Ba(2+) ions; Carmoisine; DNA-Based biosensor; Modified carbon paste electrode.