Peptide and drug functionalized fluorescent quantum dots for enhanced cell internalization and bacterial debilitation

This report illustrates a strategy for designing a nanoconjugate derived vector which efficiently delivers antimicrobial drug directly into bacterial cells. The nanoconjugate comprises of negatively charged CDTe@CdS quantum dot (QD) with its surface functionalized using catioinic BP-100 (KKLFKKILKYL-amide); a known cell penetrating peptide (CPP), via electrostatic approach. The interactions between QD and CPP in QDs functionalized CPPs (QD-CPP) have been well analysed using fluorescence spectroscopy, gel electrophoresis and zeta potential analysis. The QD-CPP conjugate was internalized into Gram-negative (E. coli) as well as Gram positive (S. aureus) bacterial strains with confocal studies exhibiting a strong signal in tested microorganisms. Further, to check the applicability of QD-CPP conjugate, as a delivery vector for generating an effective therapeutics, ampicillin molecules were conjugated on QD-CPP surface to generate QD-CPP-Amp conjugate. The CPP and drug molecules on the surface of QDs were well ...