Interaction of prednisone with dsDNA at silver nanoparticles/poly(glyoxal-bis(2-hydroxyanil))/dsDNA modified electrode and its analytical application.

This paper reports the fabrication of an electrochemical DNA biosensor for the electrochemical determination of prednisone (PRD), which is a synthetic corticosteroid. For this purpose, silver nanoparticles (AgNPs) and a new polymer film poly(glyoxal-bis(2-hydroxyanil)) (P(GBHA)) were electrochemically deposited on a glassy carbon electrode (GCE), respectively. Then, an electrochemical DNA biosensor was prepared onto this electrode surface (GCE/AgNPs/P(GBHA)) by the immobilization of dsDNA using a chronoamperometry method. The proposed electrode was characterized by FESEM, XPS, and cyclic voltammetry (CV). The interaction between the PRD and dsDNA immobilized on the GCE/AgNPs/P(GBHA) electrode was investigated via a differential pulse voltammetry (DPV) method and UV-Vis spectrophotometry. The experimental factors affecting the interaction between the PRD concentration and dsDNA were optimized. The fabricated biosensor showed a wide linear response in a PRD concentration range of 1.0-50.0 μg mL-1 depending on both the adenine and guanine base signals. The detection limit based on the guanine and adenine signals was 0.3 μg mL-1 and 0.25 μg mL-1, respectively. The sensor exhibited excellent anti-interferential ability, good stability and reproducibility and was satisfactorily employed for the electrochemical assay of PRD in serum samples. The new DNA biosensor can be utilized for the sensitive, accurate and rapid analysis of PRD.