Design of porous S-doped carbon nanostructured electrode sensor for sensitive and selective detection of guanine from DNA samples

The development of electrochemical sensor/biosensor for the sensitive and selective screening of biomolecules is an interesting research topic for diagnosing some diseases. The active interfacial surface of microporous sulfur-doped (S-doped) carbon is fabricated to design sensory protocol for selective guanine (GUA) detection in biological samples with high sensitivity. S-doped carbon nanoparticles (S-CNPs) based electrode acts as a highly active mediator with heterogeneous surfaces and multi-active centers, enabling strong binding to active centers, short distance pathways, facile electron/molecular diffusion, and low surface resistance. Specifically, the surface electrode activities might be related to the actively-doped S atom onto carbon nanosphere morphology, interface vicinity along with stacked and non-stacked particles, nano-/micro-/meso-pores like grooves, and surface heterogeneity with a number of ridges, and holes-like vortexes, and roughness. The designed S-CNP-based sensor of GUA demonstrates fast-response signaling, low detection limit (0.0026 μmol L⁻¹), and a wide linear range (0.005–0.5 μmol L⁻¹). The S-CNP sensory protocol shows a highly sensitive and selective GUA sensor liberated from hydrolyzed and DNA exposed to oxidative stresses. Our finding indicates that the designated S-CNP sensor can be used in DNA-assessing at various physiological conditions and in clinical investigation of human health quality.