Defect-Engineered Functionalized MoS₂ Quantum Dots with Enhanced Antibacterial Activity

Abstract

The rapid development of multidrug-resistant bacterial strains creates a global threat and warrants advanced strategies to control infectious diseases. Surface-modified two-dimensional molybdenum disulfide (MoS2) nanomaterials have great potential to eradicate pathogenic bacteria. In MoS2 nanosheets, the presence of atomic defects plays a crucial role in determining their physical and electronic properties. The presence of defects not only improves the extent of surface modification but also affects the generation of reactive oxygen species (ROS), which play a pivotal role in antibacterial activity. Hence, the facile preparation of MoS2 nanomaterials with a controlled degree of defects would prompt their utilization as an efficient antibacterial agent. Herein, we have demonstrated the preparation of different defect-engineered MoS2 quantum dots (QDs), followed by surface modification with thiol ligands. The extent of ligand conjugation on the MoS2 QDs highly depends on the degree of defects, and that can also enhance the aqueous stability. The functionalized MoS2 QDs possessing a higher degree of defects showed remarkably high antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) compared to the lower defect-containing MoS2 QDs. This is due to the generation of a large amount of ROS along with the increased cellular interactions of functionalized MoS2 QDs. This could potentially disrupt the bacterial cell membrane integrity to show enhanced bactericidal activity. The MRSA bacterial growth has been completely suppressed in the presence of only 0.65 μg/mL of functionalized MoS2 QDs.

Unveiling the antibacterial strategies and mechanisms of MoS2: a comprehensive analysis and future directions

“…0D MoS 2 nanoparticles exhibit a high surface area, allowing effective contact with bacteria. 61 Their small size enhances the antimicrobial activity, making them suitable for applications in targeted drug delivery and surface disinfection. However, their stability and controlled release face challenges in some cases.…”

Electronic and optical properties of chemically modified 2D GaAs nanoribbons

“…Decreasing the size of a material in a quantum dot leads to an increase in its electronic and optical energy gap 27 – 30 . Furthermore, the application potential of 2D-QDs can be significantly enhanced through chemical functionalization, which involves processes such as doping 31 , introducing vacancies 32 , 33 , or attaching chemical groups 34 – 37 . The ability to tailor the physical and chemical properties of these nanodots using these approaches has greatly expanded their range of applications.…”

Electronic and Optical Properties of Finite Gallium Sulfide Nano Ribbons: A First-Principles Study

“…In these nanodots, the electronic and optical properties can be tuned by tuning the size, where decreasing the size of a material increases its electronic and optical energy gap [48][49][50][51][52]. Another important factor that can improve the properties of quantum dots toward the required application is chemical functionalization which can be achieved by doping [53], vacancies [54,55], or attaching chemical groups [56][57][58][59]. The capacity to control the physical and chemical properties using these factors has greatly widened the application range of 2DQDs.…”