Main Article Content
This paper presents the development DNA sensors based on screen-printed gold electrode (SPGE) for specific and rapid detection of synthetic DNA diagnostic. For the objective of this work, one-stepelectrodeposition of polyaniline/polypyrrole/silver nanoparticle/graphene (PANI/PPY/AgNP/GR) was utilized as a new sensing material for enhancing electrochemical signal. The disposable SPGE and cost-effective DNA affinity biosensor based on the single-strand DNA probe tagged with anthraquinone (AQ) as redox indicator and detected the current signal with differential pulse voltammetry (DPV). Briefly, a pretreated SPGE was modified with PANI/PPY/AgNP/GR nanocomposite and immobilized by cross-linking with DNA-AQ probe. The methodology and its efficiency have been proved using cyclic voltammetry (CV). For hybridization between ssDNA-AQ probe and the synthetic target DNA on the SPGE surface was detected by monitoring the current signal from the electron transfer of AQ. Furthermore, SEM observations were performed to observe the surface changes of SPGE after electrochemical deposition. These DNA biosensor showed a good linear target DNA concentration range from 1.0 ´ 10-15 to 1.0 ´ 10-11 M with limit of detection at femtomolar. In addition, the disposable DNA sensor could also be regenerated easily and can be reused 45 times for hybridization studied. The developed DNA sensor was found rapid, cost-effective, good reusability for hybridization detection of the synthetic DNAdiagnostic and can be used as an excellent tool for future prospective clinical applications.