Effects of Gold (III) on the Luminescent Properties of Quantum Dots Capped with Mesoporous Silica

ADRIÁN A. HEREDIA; CARLOS E. AGUDELO-MORALES; ANTONIO RIBERA; RAQUEL E. GALIAN ; JULIA PEREZ-PRIETO

Conferencia; 12th Latin American Conference on Physical Organic Chemistry (CLAFQO-12); 2013

Mesoporous silica nanoparticles (m-SiO2) are materials that present regularly spaced pores between 2 and 10 nm in their structure and silanol groups on its surface. This provides materials with unique properties, such as high surface area, large pore volume, easily modified surface properties, good biocompatibility, and multiple applications.1 On the other hand, Quantum Dots (QDs) are semiconductor nanoparticles (2-100 nm) with particular optical properties, such as broad absorption and narrow emission spectra, long time fluorescence, and high photostability.2 Recently, we have shown a thermal reduction of Au(I) and Au(III), assisted by core-shell QDs. The addition of the gold salt caused initially a loss of the QD fluorescence, but it was partially or totally recovered in less than 24 h. This effect was attributed to reduction of the gold cation to Au(0) to on the QDs surface. The QD fluorescence of this hybrid system was enhanced by subsequent irradiation.3 The aim of the present work has been to deposit the gold nanoparticle homogenously on the surface of CdSe/ZnS QDs by using the channels of mesoporous silica, which is used as the QD capping ligand.  The optimization of the preparation of QDs capped with m-SiO2 (QDs@m-SiO2) and their performance in the thermal and photochemical reduction of the gold salts will be discussed.