Electrochemical detection of enzyme labeled DNA based on disposable pencil graphite electrode


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Kara P. , ERDEM A. , GIROUSI S., OZSOZ M.

JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS, vol.38, no.1, pp.191-195, 2005 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 38 Issue: 1
  • Publication Date: 2005
  • Doi Number: 10.1016/j.jpba.2004.12.011
  • Title of Journal : JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
  • Page Numbers: pp.191-195
  • Keywords: DNA biosensors, alpha-naphthol, alkaline phosphatase, electrochemistry, pencil graphite electrode, ALKALINE-PHOSPHATASE, BIOSENSORS, AMPLIFICATION, HYBRIDIZATION, STREPTAVIDIN, SEQUENCE, SYSTEM, ACID

Abstract

Electrochemical biosensor for the detection of DNA hybridization using the reduction signal of a-naphthol is described. A pencil graphite electrode was used as a working electrode. Capture probes were covalently attached on to the pencil graphite electrode surface (PGE) at the 5' end amino group by using N-(dimethylamino)propyl-N'-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide (NHS) as a coupling agent on to PGE. After capture probe immobilization on to PGE surface; probe was hybridized with complementary biotinylated oligonucleotide. Alkaline phosphatase labeled with extravidin (Ex-AP) binds to biotinylated hybrid via biotin-avidin interaction. alpha-Naphthyl phosphate (alpha-NAP) was added and the reaction between alkaline phosphatase (AP) and alpha-NAP was occurred consequently as a substrate of AP, alpha-NAP reduction signal was obtained from this reaction, at -0.100 V by using differential pulse voltammetry (DPV). Other experimental parameters were studied such as; optimizations of hybridization time, and the concentrations of capture probe, biotinylated oligonucleotide and enzyme. (c) 2005 Elsevier B.V All rights reserved.