An electrochemical DNA biosensor based on Oracet Blue as a label for detection of Helicobacter pylori

An innovative method of a DNA electrochemical biosensor based on Oracet Blue (OB) as an electroactive label and gold electrode (AuE) for detection of Helicobacter pylori, was offered. A single-stranded DNA probe with a thiol modification was covalently immobilized on the surface of the AuE by forming an Au-S bond. Differential pulse voltammetry (DPV) was used to monitor DNA hybridization by measuring the electrochemical signals of reduction of the OB binding to double-stranded DNA (ds-DNA). Our results showed that OB-based DNA biosensor has a decent potential for detection of single-base mismatch in target DNA. Selectivity of the proposed DNA biosensor was further confirmed in the presence of non-complementary and complementary DNA strands. Under optimum conditions, the electrochemical signal had a linear relationship with the concentration of the target DNA ranging from 0.3 nmol L-1 to 240.0 nmol L-1, and the detection limit was 0.17 nmol L-1, whit a promising reproducibility and repeatability. (C) 2016 Elsevier B.V. All rights reserved.