Application of tungsten disulfide quantum dot-conjugated antimicrobial peptides in bio-imaging and antimicrobial therapy

Two-dimensional (2D) tungsten disulfide (WS2) quantum dots offer numerous promising applications in materials and optoelectronic sciences. Additionally, the catalytic and photoluminescence properties of ultra-small WS2 nanoparticles are of potential interest in biomedical sciences. Addressing the use of WS2 in the context of infection, the present study describes the conjugation of two potent antimicrobial peptides with WS2 quantum dots, as well as the application of the resulting conjugates in antimicrobial therapy and bioimaging. In doing so, we determined the three-dimensional solution structure of the quantum dot-conjugated antimicrobial peptide by a series of high-resolution nuclear magnetic resonance (NMR) techniques, correlating this to the disruption of both model lipid and bacterial membranes, and to several key biological performances, including antimicrobial and anti-biofilm effects, as well as cell toxicity. The results demonstrate that particle conjugation enhances the antimicrobial and anti-biofilm potency of these peptides, effects inferred to be due to multi-dendate interactions for the conjugated peptides. As such, our study provides information on the mode-of-action of such conjugates, laying the foundation for their potential use in treatment and monitoring of infections.