Thesis
Propiedades Ópticas de puntos cuánticos de CdSe/ZnS conjugados con biomoléculas
Autor
Ing. López de la Luz, Oscar Saúl
Institución
Resumen
The optical properties of core/shell CdSe/ZnS quantum dots non conjugated and bioconjugated with antibody molecules Interleukin (IL 10) have been investigated. At the first QD emission with the peaks at 605nm, 655nm, 705nm and 800nm wavelength is studied by the photoluminescence spectroscopy. Then the Raman scattering spectra of mentioned QDs are studied.
It was revealed the variation of QD photoluminescence spectra at the bioconjugation of QDs with IL 10 antibodies. This variation is attributed to the quantum confinement Stark effect that occurs when an electric field is applied to the bioconjugated QDs. This electric field related to the electrical dipole moments of biomolecules. The Stark effect causes the band gap increases, which leads to the shift of PL peak of bioconjugated QDs into high energy range that accompanied by the asymmetry of PL bands as well. This effect has been studied in core/shell CdSe/ZnS QDs and compared with one in core/shell CdSeTe/ZnS QDs.
Raman scattering spectroscopy allowed us i) to estimate the composition of allows in CdSeTe/ZnS QDs and ii) to confirme the existence of electrical dipole moments in bioconjugated QDs. It were identified in non conjugated QDs the characteristic Raman peaks of CdSe and CdSeTe cores, ZnS shells, and amino PEG polymer. In bioconjugated quantum dots the new lines related to organic compounds in IL 10 antibodies were identified.