Graphdiyne-enhanced impedimetric detection of virus-induced infections

Accurate detection, scaled-up testing and on-site monitoring are key attributes in effective and efficient management of pandemic outbreaks. In response to the urgent need for rapid and reliable detection of viral infections, this study investigates the use of graphdiyne—a novel two-dimensional carbon allotrope—as a platform for label-free electrochemical biosensing. The RNA-dependent RNA polymerase (RdRp) fragment, immobilized on the graphdiyne surface, served as the probe for capturing the target gene specific to SARS-CoV-2. This biorecognition event was subsequently detected through electrochemical impedance spectroscopy. The graphdiyne material demonstrated a strong adsorption ability with DNA molecules, which enabled a high selectivity in distinguishing the target sequence from mutant and non-complementary sequences, making the resulting genosensor applicable even when the detected virus undergoes mutations over time. A limit of detection in the nanomolar range was achieved, with a linear dynamic range of the response between 10−9 M to 10−5 M. Coupled with the disposable printed electrodes that are portable and miniaturized sensing platforms, our developed approach can enable label-free detection to be mass-performed outside of routine laboratories.