An electrochemical DNA biosensor for highly sensitive detection of phosphinothricin acetyltransferase gene sequence based on polyaniline-(mesoporous nanozirconia)/poly-tyrosine film

A highly sensitive method for detection of DNA hybridization and phosphinothricin acetyltransferase (PAT) gene fragment, one of the screening detection genes of the transgenic plants, was developed based on the glassy carbon electrode (GCE) modified with polyaniline-(mesoporous nanozirconia)/poly-tyrosine film. The film exhibited excellent properties for immobilizing DNA probes (ss–DNA) and sensing DNA hybridization. The fabrication processes of the film, the DNA immobilization and hybridization on the film were studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and found that the electron transfer resistance (Ret) of the electrode surface increased with the concentration of the target DNA hybridized with the DNA probes, which could be applied for determination of the DNA hybridization and PAT gene. The dynamic detection range was from 1.0 × 10−13 mol L−1 to 1.0 × 10−6 mol L−1, and the detection limit was 2.68 × 10−14 mol L−1. Compared with the other electrochemical DNA biosensors based on zirconia-based materials, the proposed biosensor showed its own performance of simplicity, good stability, fine selectivity and high sensitivity.