Introduction of New Electrochemical Biosensor for Detection of DNA Hybridization

The development of DNA biosensors has recently attracted significant attentions in connection with research efforts directed at gene analysis, tissue matching, the detection of genetic disordersand forensic applications [1, 2]. To date, various sensing strategies for DNA detection such asfluorescence [3], quartz crystal microbalance [4], surface plasmon resonance spectroscopy , surface-enhanced Raman scattering and electrochemical have been employed. In this work, weintroduced a novel electrochemical DNA sensor for the detection of DNA hybridization. The new electrochemical biosensor was fabricated by modifying a screen printed graphite electrode (SPE) with gold nanoparticles decorated on graphene (AuNPs/G). The whole DNA biosensorfabrication process was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques. The probe DNA immobilization and its hybridization on the modified electrode were further studied with CV and differential pulse voltammetry(DPV). Under optimum conditions, the developed biosensor showed a good linear relationship between the current value and logarithm of the target DNA concentration ranging from 0.5 fM to 0.05 nM with a detection limit of 3.64×10−16 M. Moreover the biosensor could effectively recognize the complementary target DNA from single base mismatched and non complementary target sequences.

Keywords:

Screen printed electrode , Graphene nanosheets , DNA hybridization , and Differential pulse voltammetry