Abstract

Electrochemical biosensors have a key importance in many areas including clinical, biological, pharmaceutical, forensic, environmental and agricultural applications. They have the advantages of rapid, easy and low cost preparation allowing the localization of biocompound on electrodes of any size with independence of sample turbidity, high sensitivity and high selectivity. Electrochemical devices have attracted considerable interest in the development of DNA hybridization biosensors. They rely on the conversion of hybridization event into a direct electrochemical signal. Many efforts have been carried out in the detection of DNA hybridization for improving the stability, reproducibility and sensitivity.

This review summarizes the advanced electrochemical methodologies involved in nucleic acid hybridization performed by using polymer technology, nanoparticles (NPs), magnetic particles, and carbon nanotubes (CNTs). The preparation of polymer modified electrodes especially including conducting polymers and their applications for DNA hybridization are given with the advantages of electrocatalysis, good electroactivity, high sensitivity and providing suitable matrix for DNA immobilization. The role of various nanomaterials in biosensors with the advantages of high surface area, fast heterogeneous electron transfer, excellent biocompatibility and enhanced signal with a good selectivity are presented. The combination of these techniques is also discussed in details.

Keywords: Biosensor, DNA, Nucleic acid hybridization, Electrochemical DNA biosensor, Polymer, Nanoparticle, Magnetic particle, Carbon nanotube, Label free approach, Label based approach, Conducting Polymers, Metallic Nanoparticles, Semiconductor Nanoparticles, Metal Oxide Nanoparticles, MAGNETIC PARTICLES, Salmonella spp, graphite-epoxy composite (GEC), magneto-GEC electrodes, Human Immunodeficiency virus (HIV), HBV virus, nonfaradic electrochemical impedance spectroscopy (EIS), MWCNT-streptavidin conjugates