An efficient DNA electrochemical biosensor, based on the gold nanoparticles (GNPs) in situ synthesized at the surface of multiwalled carbon nanotubes (MWCNTs), cerium dioxide (CeO2) and chitosan (Chits) composite membrane, was developed for the detection of BCR/ABL fusion gene in chronic myelogenous leukemia (CML). The capture probe was attached onto the nanocomposite membrane modified glassy carbon electrode (GCE) through the conjugated structure. Owing to the synergistic effects of CeO2 nanoparticles with a strong adsorption ability and MWCNTs with a large surface area and excellent electron transfer ability, the prepared composite membrane was demonstrated an efficient electron transfer ability. The biosensor was electrochemically characterized by cyclic voltammogram (CV) and differential pulse voltammetry (DPV), and the decrease of the peak currents upon hybridization was observed using methylene blue (MB) as the electroactive indicator. Under the optimized conditions, peak currents were linear over the range from 1 × 10(-9) M to 1 × 10(-)(12) M, with a detection limit of 5 × 10(-)(13) M (based on the 3σ). And the proposed method was successfully applied for the detection of PCR real samples with satisfactory results. Furthermore, the developed DNA biosensor was demonstrated a good selectivity, a reasonable stability and a favorable reproducibility, which could be regenerated easily.
Keywords: BCR/ABL fusion gene; Cerium dioxide; Electrochemical DNA biosensor; In situ synthesis; Methylene blue.
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