Catalogo de Investigaciones 2018-2019

36 CIENCIAS Ligand Exchange and toxicity of CdSSe quantum dots on chinese hamster ovary cells Quantum dots (QDs) are nanoparticles with diameters in the range of 1-1oo nm. Depending on the material, they have different properties such as high electron density, magnetic moment, phosphorescence, photoluminescence (fluorescence), and/or strong optical absorption. Photoluminescence of the QDs is dependent on the crystal size. QDs have a wide excitation band and a narrow emission band, some of them within the visible spectrum. The layer on the surface (thioglycolic acid) of the CdSSe QDs has a vital role in the synthesis because it allows the stabilization and practical uses on different matrixes. The thioglycolic residues on the CdSSe QD surface can determinate the chemical properties of QDs like dispersity, charge transference, and the interparticle space. Also, it changes their optical and electronic properties. The process by which the native layer is exchanged for new layer is called ligand exchange. In this process, the original ligand is de-adsorbed, and the selected ligand is bound to the QD. Ligand exchange is commonly carried out to incorporate functional groups that alter the solubility of the QD, introduce electron transfer partners, integrate biological receptors or improve the exposure of the QD surface. jury cruz hernández maestría en ciencias con especialidad en química mentor: dr. luis álamo nole quantum dots ligand exchange cdsse cho cells