Electrochemical Detection of Global DNA Methylation Using Biologically Assembled Polymer Beads

DNA methylation is a cell-type-specific epigenetic marker that essential for transcriptional regulation, silencing of repetitive and genomic imprinting. It also responsible the pathogenesis many diseases, including cancers. Herein, we present simple approach quantifying global in ovarian cancer patient plasma samples based on new class biopolymer nanobeads. Our utilises immune capture target electrochemical quantification level within targets three-step strategy involves (i) initial preparation single-stranded (ss-DNA) from patients’ samples, (ii) direct adsorption polymer nanobeads surface bare screen-printed gold electrode (SPE-Au) followed by immobilisation 5-methylcytosine (5mC)-horseradish peroxidase (HRP) antibody, (iii) ss-DNA onto electrode-bound PHB/5mC-HRP antibody conjugates their subsequent qualification using hydrogen peroxide/horseradish peroxidase/hydroquinone (H2O2/HRP/HQ) redox cycling system. In presence methylated DNA, enzymatically produced (in situ) metabolites, i.e., benzoquinone (BQ), binds irreversibly to cellular resulting unstable formation adducts induced oxidative strand breakage. These events reduce available BQ system support process sequel saturation platform, subsequently causing high Coulombic repulsion between negatively charged nucleotide strands. Thus, increase levels inversely proportional current response. The method could successfully detect as low 5% level. addition, assay showed good reproducibility (% RSD ≤ 5%) specificity analysing various cell lines patients with cancer. We envision our bioengineered modification versatility be useful alternative platform detection varying molecular biomarkers.