Fluorescence quantum efficiency of CdSe/ZnS quantum dots embedded in biofluids: pH dependence

Author(s)

Pilla, Viviane ^[1] ; Alves, Leandro P. ^[2] ; de Santana, Juliana F. ^[1] ; da Silva, Leandro G. ^[3] ; Ruggiero, Reinaldo ^[3] ; Munin, Egberto ^[2]

Affiliation

^[1] Univ Fed Uberlandia, Inst Fis, BR-38400902 Uberlandia, MG - Brazil

^[2] Univ Camilo Castelo Branco UNICASTELO, Ctr Biomed Engn, BR-12247004 Sao Paulo - Brazil

^[3] Univ Fed Uberlandia, Inst Quim, BR-38400902 Uberlandia, MG - Brazil

• Document type: Journal article
• Source: Journal of Applied Physics; v. 112, n. 10 NOV 15 2012.
• Web of Science Citations: 7

Abstract

The radiative quantum efficiency (g) of CdSe/ZnS core-shell quantum dots (QDs) embedded in synthetic oral fluid was measured using a thermal lens (TL) technique. TL transient measurements were performed using the mode-mismatched dual-beam (excitation and probe) configuration. Thermal optical characterization of CdSe/ZnS QDs was performed for two different core sizes (3.9 and 5.1 nm) incorporated into synthetic saliva with different potential of hydrogen (pH 4-8) values. The thermal diffusivity (D) and average emission wavelength (<lambda(em)>) results are approximately independent of the pH of the solutions evaluated. The fractions of absorbed energy converted into heat (phi) and eta are dependent on both the fluid pH and core size of the CdSe/ZnS core-shell QDs. The dependence on pH was also evidenced by fluorescence measurements, which corroborate the results obtained by the thermal lens technique. (C) 2012 American Institute of Physics. {[}http://dx.doi.org/10.1063/1.4767470] (AU)

• FAPESP's process: 06/01277-2 - Nonlinear spectroscopy in quantum dots functionalized for biological applications
• Grantee: Viviane Pilla
• Support Opportunities: Regular Research Grants