Optimum quantum dot size for highly efficient fluorescence bioimaging

Martinez Maestro, L; Jacinto, C; Rocha, U; Iglesias-de la Cruz, MC; Sanz-Rodriguez, F; Juarranz, A; Garcia Sole, J; Jaque, D

Abstract

Semiconductor quantum dots of few nanometers have demonstrated a great potential for bioimaging. The size determines the emitted color, but it is also expected to play an important role in the image brightness. In this work, the size dependence of the fluorescence quantum yield of the highly thermal sensitive CdTe quantum dots has been systematically investigated by thermal lens spectroscopy. It has been found that an optimum quantum yield is reached for 3.8-nm quantum dots. The presence of this optimum size has been corroborated in both one-photon excited fluorescence experiments and two-photon fluorescence microscopy of dot-incubated cancer cells. Combination of quantum yield and fluorescence decay time measurements supports that the existence of this optimum size emerges from the interplay between the frequency-dependent radiative emission rate and the size-dependent coupling strength between bulk excitons and surface trapping states.

Citation

Martinez Maestro, L., Jacinto, C., Rocha, U., Iglesias-de la Cruz, M., Sanz-Rodriguez, F., Juarranz, A., …Jaque, D. (2012). Optimum quantum dot size for highly efficient fluorescence bioimaging. Journal of Applied Physics, 111(2), 023513. https://doi.org/10.1063/1.3676251

• Journal Article Type: Article
• Acceptance Date: Dec 12, 2011
• Online Publication Date: Jan 25, 2012
• Publication Date: Jan 25, 2012
• Deposit Date: Dec 5, 2019
• Publicly Available Date: Dec 5, 2019
• Journal: Journal of Applied Physics
• Print ISSN: 0021-8979
• Electronic ISSN: 1089-7550
• Publisher: AIP Publishing
• Volume: 111
• Issue: 2
• Pages: 023513
• DOI: https://doi.org/10.1063/1.3676251
• Publisher URL: https://doi.org/10.1063/1.3676251
• Additional Information: Funders : Universidad Auto´noma de Madrid;Comunidad Autonoma de Madrid;Spanish Ministerio de Educacion y Ciencia;Banco Santander CEAL-UAM;Brazilian agencies CAPES, CNPq, and FAPEAL