Electrochemical biosensor based on nanoporous gold electrode for detection of PML/RARα fusion gene

In this study, a kind of nanoporous gold electrode (NPG) prepared with repetitive square-wave oxidation reduction cycle (SWORC) was reported. The active surface area of the proposed NPG electrode was 9.9 times larger than that of a bare flat one characterized by cyclic voltammetry (CV). An electrochemical DNA biosensor based on NPG electrode was fabricated for detection of promyelocytic leukemia/retinoic acid receptor α (PML/RARα) fusion gene in acute promyelocytic leukemia (APL) by using Methylene Blue (MB) as an electroactive indicator. Differential pulse voltammetry (DPV) was employed to monitor the hybridization reaction on the probe modified electrode. The decrease of the peak current of MB was observed upon hybridization of the probe with target DNA. The results indicated that the peak current was linear with the concentration of complementary strand in the range of 60 pM to 220 pM with a detection limit of 6.7 pM. This new biosensor exhibited excellent sensitivity and selectivity and had been used for an assay of PCR real sample with a satisfactory result.