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Assessing Single Upconverting Nanoparticle Luminescence by Optical Tweezers
P Rodríguez-Sevilla1, H Rodríguez-Rodríguez1, M Pedroni2
1†Fluorescence Imaging Group, Departamento de Física de Materiales, Modulo 4, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente 7, Madrid 28049, Spain.
Nano Letters
|June 30, 2015
Summary
We achieved stable trapping of single upconverting fluorescent nanoparticles (UCNPs) using optical trapping. Unexpectedly, single UCNP emission differs from nanoparticle assemblies due to radiation-trapping effects.
Area of Science:
- Nanotechnology
- Optical Physics
- Spectroscopy
Background:
- Colloidal nanoparticles offer unique optical properties.
- Upconverting fluorescent nanoparticles (UCNPs) are promising for various applications.
- Controlling and understanding single nanoparticle behavior is crucial.
Purpose of the Study:
- To achieve stable, long-term optical trapping of single UCNPs.
- To investigate the optical emission characteristics of single UCNPs.
- To understand the influence of trapping on UCNP emission.
Main Methods:
- Optical trapping using a single infrared laser beam.
- Spectroscopic analysis of single and assembled UCNPs.
- Theoretical modeling to explain observed phenomena.
Main Results:
- Stable, long-term immobilization of single Er(3+)/Yb(3+) codoped UCNPs was achieved.
- Single UCNP emission spectra were found to differ from those of nanoparticle assemblies.
- Radiation-trapping effects were identified as the cause of emission modulations.
Conclusions:
- Optical trapping enables precise manipulation of single UCNPs.
- Radiation-trapping significantly impacts single UCNP emission, contrary to previous assumptions.
- This finding is relevant for applications utilizing UCNP luminescence.
