ABSTRACT
Ethyl butyrate (EB) was identified in recent research as a prominent biomarker of COVID-19, as concentrations of EB were higher in exhaled breath of COVID-19 patients. Electronic sensitivities of pristine, Al- and Si-doped BC3 nanosheets to the EB molecule were investigated in this study using density functional theory. It is found that the pure BC3 was ineffective in sensing EB due to low adsorption energy and sensitivity. Aluminum- and silicon-doped BC3 nanosheets were effective in forming a strong interaction with EB and were also sensitive. Our calculations show that the band gaps of the Al-doped and Si-doped BC3 sheets were significantly decreased upon EB adsorption, which increased the electrical conductance of the sheets and the sensitivity. However, Si-doped BC3 had a recovery time of almost 22 hours, making it less potent than Al-doped BC3, which had a recovery time of just 7.7 minutes. The shorter recovery time of the Al-doped BC3 sheet is due to its moderate adsorption energy of 25.8 kcal mol-1. These results can help facilitate the development of an EB biosensor for COVID-19 testing and other similar applications.