Antibacterial and optical properties of a new water soluble CdSe quantum dots coated by multidentate biopolymer

A facile approach for surface passivation of water-soluble CdSe quantum dots (CdSe QDs) by new water-soluble multidentate biopolymer based on poly ((2-dimethylaminoethyl) methacrylate) grafted onto salep (salep-g-PDMA) is devised. The transmission electron micrographs (TEM) revealed an average size of 4.5 nm for QDs. The Fourier transform infrared spectra (FT-IR) were used to ascertain the functional groups of biopolymers on the surface of QDs. The obtained QDs samples showed significant improvement in their thermal behavior as indicated by thermo gravimetric analysis (TGA). The optimum conditions regarding to monomer concentration, CdSe/salep-g-PDMA ratio and temperature were obtained to achieve the highest FL intensity of the passivated QDs. Lastly, the in vitro antibacterial properties of the obtained optimum sample were investigated against gram-negative and gram-positive bacteria.