Highly sensitive lung cancer DNA detection via GO enhancing eATRP signal amplification

Abstract Atom transfer radical polymerization (ATRP) is an effective polymerization technology, and low ppm ATRP attracts unceasing interest in biological field. In this work, a fast and effective electrochemical biosensor based on graphene oxide (GO) via electrochemically mediated ATRP (eATRP) realized the ultrasensitive detection of lung cancer DNA. Peptide nucleic acid (PNA) was used as capture probes to specifically recognize target DNA, GO was connected to PNA/DNA heteroduplexes via phosphate-Zr4+-carboxylate chemistry to introduce eATRP initiators. Under a potentiostatic condition, eATRP was initiated with the help of reducibility of electrons, and numerous monomers labeled with ferrocene moieties were grafted onto GO. GO was synthesized by modified Hummer’s method and was characterized by Fourier transform infra-red spectra (FT-IR) and X-ray diffraction (XRD). The analytical performance of this biosensor was evaluated by square wave voltammetry (SWV) under optimal conditions, its limit of detection (LOD) was 0.213 aM (R2=0.994) with a linear range from 1.0 aM to 100 fM. High selectivity of this biosensor indicated a good application potential of genotyping of single nucleotide polymorphisms (SNPs), and simple operation and highly sensitive analytical performance endowed this biosensor a superior application prospect. More importantly, a novel thinking for material application in biological detection was provided in this work.