Voltammetric Determination of Adenovirus Specific DNA Sequence Using Self-Assembled Dimercapto-Succinic acid Monolayer on Gold Electrode

Abstract

A novel electrochemical DNA biosensor for the detection of adenovirus specific DNA sequence is presented in this paper. Dimercapto succinic acid was self-assembled on gold electrode surface and amino group ended single-strand DNA (NH₂-ssDNA) probe was immobilized covalently to carboxylic group of dimercapto succinic acid monolayer in the presence of 1-ethyl-3-(3- dimethylamino-propyl)carbodiimide and N-hydroxysulfosuccinimide sodium salt as linker. The NH₂-ssDNA probe was hybridized with complementary ssDNA in solution. Meanwhile, Co(phen)₃³⁺ as electrochemical hybridization indicator was intercalated into double stranded DNA (dsDNA) to form a dsDNA/Co(phen)₃³⁺ system on the gold surface. Differential pulse voltammetry was utilized to detect an increase of redox peak current of Co(phen)₃³⁺ on dsDNA/ Au electrode. Using this method, an adenovirus specific DNA sequence could be quantified over the range from 1.03 × 10^-9-2.06 × 10^-7 mol/L^-1. The detection limit is 5.23 × 10^-10 mol/L^-1.