Work

Ultrasmall Monodisperse NaYF 4 :Yb 3+ /Tm 3+ Nanocrystals with Enhanced Near-Infrared to Near-Infrared Upconversion Photoluminescence

Year: 2010

Type: article

Abstract: Photoluminescent NaYF(4):Yb(3+)/Tm(3+) nanocrystals are ideally suited for in vitro and in vivo photoluminescence (PL) bioimaging due to their virtue of near-infrared to near-infrared (NIR-to-NIR) upconversion (UC); they display PL with a peak at approximately 800 nm if excited at approximately 980 nm. Here, we report the synthesis of monodisperse NaYF(4):Yb(3+)/Tm(3+) nanocrystals of ultrasmall size (7-10 nm) with high UC efficiency. The intensity of their NIR UC emission was demonstrated to increase by up to 43 times along with an increase in the relative content of Yb(3+) ions from 20 to 100%, with a corresponding decrease in the Y(3+) content from 80 to 0%. The achieved ultrasmall NaYbF(4):2% Tm(3+) nanocrystals manifest NIR PL emission, which is 3.6 times more intense than that from 25-30 nm sized NaYF(4):20% Yb(3+)/2% Tm(3+) nanocrystals, previously synthesized and used for in vitro and in vivo bioimaging. An optimization of both size and UC PL efficiency of NIR-to-NIR nanocrystals provides us with highly efficient optical imaging probes for bioapplications.

Source: ACS Nano

DOI: 10.1021/nn100457j

Authors: Guanying Chen, Tymish Y. Ohulchanskyy, Rajiv Kumar, Hans Ågren, Prasas N. Prasad

Institutions: University at Buffalo, State University of New York, KTH Royal Institute of Technology

Language: English

Topic: Luminescence Properties of Advanced Materials

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funder: National Cancer Institute

Awards: Novel Cancer Nanotechnology Platforms for Photodynamic Therapy and Imaging, Application of Nanotechnology in Photodynamic Therapy