Application of borophene as catechol sensor: a computational study

Anab initiostudy of catechol sensing in pristine and transition metal decoratedγ-graphyne

Catechol is a toxic biomolecule due to its low degradability to the ecosystem and unpredictable impact on human health. In this work, we have investigated the catechol sensing properties of pristine and transition metal (Ag, Au, Pd, and Ti) decoratedγ-graphyne (GY) systems by employing the density functional theory and first-principles molecular dynamics approach. Simulation results revealed that Pd and Ti atom is more suitable than Ag and Au atom for the decoration of the GY structure with a large charge transfer of 0.29e and 1.54e from valence d-orbitals of the Pd/Ti atom to the carbon-2p orbitals of GY. The GY + Ti system offers excellent electrochemical sensing towards catechol with charge donation of 0.14e from catechol O-p orbitals to Ti-d orbitals, while the catechol molecule is physisorbed to pristine GY with only 0.04e of charge transfer. There exists an energy barrier of 5.19 eV for the diffusion of the Ti atom, which prevents the system from metal-metal clustering. To verify the thermal stability of the sensing material, we have conducted the molecular dynamics simulations at 300 K. We have reported feasible recovery times of 2.05 × 10^-5s and 4.7 × 10²s for sensing substrate GY + Pd and GY + Ti, respectively, at 500 K of UV light.

Catechol sensor based on pristine and transition metal embedded holey graphyne: a first-principles density functional theory study

To develop a highly sensitive and selective biosensor for detecting noxious biomolecules from the environment, we examined catechol (Cc) adsorption in pristine and transition metal (TM = Sc, Cu, and Pd) embedded 2D holey graphyne (hGY) monolayers using the first-principles density functional theory method. The interaction between Cc and the pristine hGY is purely weak, and hence the response of the sensing device will be difficult to detect. Therefore, the TM doping strategy is adopted to improve the sensitivity. According to our findings, Sc binds strongly to the hGY monolayer, with a binding energy of -4.09 eV and a charge transfer of 1.89e from the valence orbitals of Sc to the C 2p orbitals. Later on, the Cc adsorption on the TM-embedded hGY was investigated. The interaction of Cc with the transition metal involves charge transfer from Cc to the metal d orbital. A large binding energy of -3.22 eV and a significant charge transfer of about 0.9e from the O 2p orbitals of Cc to the valence orbital of Sc suggest that the Sc embedded hGY monolayer is a good choice for the efficient sensing of Cc molecules. Furthermore, ab initio MD simulations confirmed the structural stability of the Sc + hGY system at room temperature. We strongly believe that this theoretical work will aid the experimentalists in designing and developing 2D semiconducting nanolayer-based biosensors for commercial purposes.