Label-free and enhanced DNA sensing platform for PML/RARA fusion gene detection based on nano-ZnO functionalized carbon ionic liquid electrode

A novel electrochemical impedance DNA biosensor for acute promyelocytic leukemia was developed by immobilizing a PML/RARA related 18-mer oligonucleotides ssDNA sequence on carbon ionic liquid electrode modified with nanosized ZnO. The morphology of ZnO nanoparticles was characterized by using scanning electron microscopy. Cyclic voltammetry and electrochemical impedance spectroscopy were performed for the study of decoration of ZnO, immobilization of ssDNA and the hybridization event at the electrode surface. Remarkable change has been observed in the impedance spectra before and after hybridization of probe ssDNA with the target DNA under optimal conditions. As a result, the effective probe immobilization platform, coupled with the ultrasensitive label-free impedance measurement, gave rise to a detection limit of 2.5 × 10−13 mol/L.