A sensitive electrochemical method for DNA hybridization based on immobilization of DNA probe and [Ru(NH3)5Cl]PF6 complex onto nickel oxide nanomaterials (NiOxnp) modified glassy carbon electrode was developed. Due to strong affinity of NiOxnp for phosphate groups, oligonucleotides probe with a terminal 5′phosphate group was attached to the surface of the modified electrode. DNA immobilization and hybridization were characterized by electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry using K3Fe(CN)6/K4Fe(CN)6 and [Ru(NH3)5Cl]PF6 as probe and indicator, respectively. The Rucomplex current response indicates only the complementary sequence showing an obvious current signal in comparison to noncomplementary and three or single point mismatched sequences. The fabricated biosensor possessed good selectivity and sensitivity for complementary probe, taxon: 32630 tumor necrosis factor (TNF). The linear dynamic range, sensitivity and detection limit of the proposed biosensor were 4×10−10M to 1×10−8 M, 34.32 nAnM−1 and 6.8×10−11 M, respectively. Excellent reproducibility and stability, quite simple and inexpensive preparation are the other advantages of proposed biosensor.
