Amino Acid-Functionalized MoS₂ Quantum Dots for Selective Antibacterial Activity

The surface functionalization of nanomaterial is relevant in terms of its selectivity toward a bacterial strain. Recently, semiconducting nanomaterials have been gaining much attention in the development of nanomaterial-based alternative antibiotics. Among the various semiconducting materials, molybdenum disulfide (MoS2) has been gaining considerable interest due to its unique electronic, physical, and chemical properties. The semiconducting nature, high colloidal stability, and biocompatibility make it a promising candidate in the field of biomedical research. The development of antibacterial material based on MoS2 quantum dots is still in its infancy. Here, we have explored the effect of hydrophobic amino acid-modified MoS2 quantum dots toward their antibacterial activity. Functionalization enhances the antibacterial activity and selectivity depending on the amino acid residue. MoS2 quantum dots with a leucine-functionalized ligand show selective antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), whereas MoS2 quantum dots with a phenylalanine-functionalized ligand show almost equal antibacterial efficacy against both MRSA and Pseudomonas aeruginosa (PA).