A Sensitive Electrochemical Genosensor for the Detection of p53, a Tumor Suppressor Gene using A Simple Method for Tag-Free ssDNA Immobilization based on Ceria Nanoparticles

A sensitive electrochemical genosensor was introduced and developed for a tumor suppressor gene, p53, detection. An Au screen-printed electrode coated with polyaniline film and ceria nanoparticles decorated on reduced graphene oxide was employed. To generate the genosensor, a suitable ssDNA probe sequence was immobilized on the modified surface of a glassy carbon electrode without re-quiring any labeling or tagging moieties. The surface properties of the resulting electrodes were evaluated through scanning electron microscopy (SEM) and atomic force microscopy (AFM). Hy-bridization phenomena of the probe and its target sequence were followed by differential pulse voltammetric signal of tris(bipyridine) ruthenium(II) chloride as an electrochemical probe. The detection limit was found to be 1 fM, and the DPV current was pro-portional to the logarithm of the p53 ssDNA concentration from 10 fM to 0.1 nM. The proposed genosensor showed excellent sen-sitivity, high selectivity, and reasonable reproducibility, which can be useful in future cancer di-agnosis microdevice development.