A comparative DFT study of drug delivery system based on Pt-doped and Au-modified MoS2 nanosheets for β-lapachone drug

Abstract

This study analyzed the interaction of β-lapachone (C₁₅H₁₄O₃) drug onto the pristine, Pt-doped, and Au-modified MoS₂ nanosheets using density functional theory (DFT). Pristine MoS₂ was found not to be strongly connected to the β-lapachone molecule and thus was not conductive to propose promising drug sensing system. The thermodynamic stability of both Pt-doped and Au-modified MoS₂ nanosheets was described using the calculated negative formation energies. On the other hand, Pt-doped and Au-modified MoS₂ exhibited higher binding energy and strength towards β-lapachone drugs. Pt-doped MoS₂ showed stronger interaction with β-lapachone drugs than Au-modified MoS₂ thanks to stronger orbital interactions and adsorption capacity. Both Pt-doped and Au-modified MoS₂ systems exposed semiconductor character based on band structure analysis. The charge density difference diagrams show the great accumulation of charge densities on the adsorbed β-lapachone drug. Due to the better conductivity, the drug carrier ability of the Au-modified and Pt-doped MoS₂ substrates are improved over the intrinsic MoS₂. The significant overlaps in the PDOS plots of Pt and O atoms indicate sufficient hybridization between them to form chemical bonds. The addition of noble metals such as Au and Pt may suggest a promising MoS₂-based biosensor towards adsorption and detection of β-lapachone drugs for the design of effective drug delivery systems.