Outstanding Performance of Transition-Metal-Decorated Single-Layer Graphene-like BC₆N Nanosheets for Disease...

In the present work, we report highly sensitive and selective nanosensors constructed with metal-decorated graphene-like BC₆N employing nonequilibrium Green's function (NEGF) formalism combined by density functional theory (DFT) toward multiple inorganic and sulfur-containing gas molecules (NO, NO₂, NH₃, CO, CO₂, H₂S, and SO₂) as disease biomarkers from human breath. Monolayer sheets of pristine BC₆N and Pd-decorated BC₆N were evaluated for their gas adsorption properties, electronic property changes, sensitivity, and selectivity toward disease biomarkers. The pristine BC₆N nanosheets exhibited sharp drops in the bandgap when interacted with gases such as NO₂ while barely affected by other gases. However, the nanosecond recovery time and low adsorption energies limit the gas sensing applications of the pristine BC₆N sheet. On the other hand, the Pd-decorated BC₆N-based sensor underwent a semiconductor to metal transition upon the adsorption of NO gas molecules. The conductance change of the sensor's material in terms of I-V characteristics revealed that the Pd-decorated BC₆N sensor is highly sensitive (98.6-134%) and selective (12.3-74.4 times) toward NO gas molecules with a recovery time of 270 s under UV radiation at 498 K while weakly interacting with interfering gases in exhaled breath such as CO₂ and H₂O. The gas adsorption behavior suggests that metal-decorated BC₆N sensors are excellent candidates for analyzing pulmonary disease and cardiovascular biomarkers, among other ailments of the stomach, kidney, and intestine.