Journal of Chongqing University (English Edition) [ISSN 1671-8224]
Vol. 9 No. 2
June 2010
100
Article ID: 1671-8224(2010)02-0100-05
To cite this article: ZHANG Hao-bo, LI Jin-du, ZHAO Jun, YANG Xi. Electrochemical investigation of DNA hybridization to ferrocene-labelled peptide nucleic acid on gold
electrodes [J]. J Chongqing Univ: Eng Ed [ISSN 1671-8224], 2010, 9(2): 100-104.
Electrochemical investigation of DNA hybridization with ferrocene-
labelled peptide nucleic acid on gold electrodes
ZHANG Hao-bo
1,†
, LI Jin-du
2
, ZHAO Jun
1
, YANG Xi
1,‡
1
College of Science, Gansu Agricultural University, Lanzhou 730070, P. R. China
2
Shandong Xinhua Pharmaceutical Company Limited, Zibo 255005, Shandong Province, P. R. China
Received 30 March 2010; received in revised form 12 May 2010
Abstract: An electrochemical DNA sensor based on ferrocene-labelled peptide nucleic acid (PNA-Fc) was prepared. The
hybridization between PNA-Fc and DNA immobilized on a gold electrode was examined by cyclic voltammetry (CV) and
differential pulse voltammetry (DPV). PNA-Fc shows a good electrochemically activity and has a redox potential of 170 mV
verus Ag/AgCl electrode after hybridization, representing the characteristic of ferrocene/ferrocenium (Fc/Fc+) transformation.
The results illustrate that PNA-Fc can be used as an effective electrochemical DNA probe sensor.
Keywords: peptide nucleic acid; ferrocene; electrochemical sensor
CLC number: O646.54 Document code: A
1 Introduction
a
Genetic testing is one of the foremost topics in
current biochemical research. However, traditional
methods of detecting DNA hybridization like gel
electrophoresis and membrane blots are too slow and
labor intensive. Many different approaches have been
proposed for genetic tests [1] including the DNA
hybridization sensor, which, in particular, is one of the
fastest growing areas in genetic testing technology and
has attracted increasing attention of applications in
clinical diagnostics, environmental protection, food
quality control, and forensic science [2-3]. DNA
sensors are small analytical devices. They form a
nucleic acid recognition layer immobilized on a
physical transducer to recognize by hybridization its
complementary target sequence and convert the DNA
hybridization event into a useful analytical signal.
Because electrochemical analytical devices are rapid,
†
ZHANG Hao-bo (张浩波): zhanghb@gsau.edu.cn.
‡
Corresponding author, YANG Xi (杨晰): lily_yang0908@sina.com.
easy-to-use, inexpensive and miniaturized, electro-
chemical methods are a better choice than many other
methods. One electrochemical method using peptide
nucleic acid (PNA) is broadly applied to DNA research.
In addition, electrochemistry offers innovative routes
for interfacing the nucleic acid recognition system with
the signal-generating element and amplifying electrical
signals. Thereby, electrochemical methods have drawn
great attention in the last few decades. They use small
electroactive DNA-intercalating or groove-binding
substances as the indicators, which have a much higher
affinity for resulting hybrids than a single-stranded
probe. The increasing interest in electrochemical
methods for hybridization detection arises from the
high sensitivity. A current strategy of monitoring DNA
hybridization with a complementary strand is based on
the change of the electrochemical response of labeling
DNA with metal complexes or electroactive
compounds. Ferrocene or its derivatives are very good
redox-active molecules with excellent redox
reversibility and the advantages of being chemically
stable, easily functionalized and electrochemically
reversible [3-7].
Ferrocenylated oligodeoxynucleotides used as