Diagnosis of Helicobacter pylori bacterial infections using a voltammetric biosensor

Abstract

The voltammetric assay of Helicobacter pylori DNA was investigated using a bismuth-immobilized carbon nanotube electrode (BCNE). The analytical cyclic voltammetry (CV) peak potential was obtained at a 0.4 V reduction scan, where the diagnostic optimum square-wave (SW) stripping working range was achieved at 0.72-7.92 mu g/mL H. pylori DNA (11 points). A relative standard deviation of 1.68% (RSD, n = 5) was obtained with 3.2 mg/mL H. pylori DNA using a 240 s accumulation time. Under optimum conditions, detection limit was 0.06 mu g/mL The developed sensors can be used for clinical application in the 15th doubted human gastric tissues, since the patient's peak current increased a hundred times more than the negative healthy tissue did. The sensing time obtained was only two minutes, and the process was simpler compared to common PCR amplification and electrophoresis photometric detection systems. (C) 2011 Elsevier B.V. All rights reserved.