A printable voltammetric genosensor for tumour suppressor gene screening based on a nanocomposite of Ceria NPs–GO/nano-PANI

Abstract

A novel voltammetric screen printed genosensor has been developed for detecting mutation in a particular sequence of the adenomatous polyposis coli (APC) gene, which is classified as a tumor suppressor gene. This gene prevents uncontrolled growth of cells which can cause cancerous tumors. For this purpose, a screen-printed carbon electrode (SPCE) surface was modified with a nano-polyaniline (nano-PANI) and graphene oxide (GO)-ceria nanocomposite (Ceria NPs–GO/nano-PANI/SPCE). Ceria NPs–GO was a suitable base for label-free immobilizaition of a single strand oligonucleotide probe. The composite was able to catalyze a difference pulse voltammetry (DPV) redox signal of Tris(bipyridine) ruthenium(II) chloride utilized as a redox probe for monitoring the hybridization of DNA. The genosensor displayed excellent performance over the linear range from 1 × 10⁻⁵ to 5 × 10⁻² μmol L⁻¹ with a limit of detection of 5.7 × 10⁻⁶ μmol L⁻¹. Also, it can distinguish a target sequence from three mismatch base sequences successfully.