Two-dimensional Janus monolayers of MoSSe as promising sensor towards selected adulterants compounds

Selective detection of different types of adulterants present in food items is necessary and efficient nano sensors for such applications are of vital importance. In this study, recently synthesized two-dimensional (2D) Janus monolayer of MoSSe has been explored to detect various food adulterants like formalin (CH₂O), histamine (C₅H₉N₃) and hydrogen peroxide (H₂O₂). By using first principles density functional theory calculations, we find that the incident adulterants weakly bind with pristine MoSSe, however the adsorption energies (E_ads) are significantly improved upon vacancy defects and foreign elements substitutions. Furthermore, the sensing mechanism is studied in presence of water for the applications in practical working conditions. Energetic evaluation shows that both H₂O₂ and histamine result into stronger E_ads as compared to formalin over defect induced MoSSe; whereas, the presence of water further enhances the adsorption of H₂O₂. In addition to the adsorption characteristics, charge transfer mechanism and electronic structures of pristine and defect induced MoSSe monolayers upon the exposure of studied adulterants have also been studied. Boltzmann thermochemical statistics further verified the explicabilities of pristine and defected MoSSe monolayers for in vitro test of adulterants in food products. Suitable E_ads values and measurable changes in the electronic properties indicate the potential of MoSSe monolayers as efficient nano sensors towards selected adulterants for their applications in food processing, biotechnology, healthcare and medical laboratories.