Related Experiment Video
Updated: Jun 13, 2026
13:39
Optical Trapping of Nanoparticles
Published on: January 15, 2013
27.3K
Sensing with (One or Many) Upconverting Nanoparticles
Fernando E Maturi1,2, Erving Ximendes1,2, Antonio Benayas1,2,3
1Nanomaterials for Bioimaging Group, Departamento de Física de Materiales, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
Accounts of Chemical Research
|April 30, 2026
Summary
Lanthanide-doped upconverting nanoparticles (UCNPs) offer unique intracellular thermometry and single-particle manipulation capabilities. Their performance in biological environments and optical traps depends heavily on surrounding conditions, requiring further study for reliable nanoscale sensing.
Area of Science:
- Nanotechnology and Materials Science
- Biophysics and Chemical Biology
Background:
- Lanthanide-doped upconverting nanoparticles (UCNPs) convert near-infrared (NIR) light to visible emission, enabling applications in biological sensing and single-particle studies.
- UCNPs are practical for intracellular thermometry due to their narrow emission lines, photobleaching resistance, and thermal coupling, measurable with standard microscopy.
- However, the complex intracellular environment can alter UCNP emission properties, affecting thermometry reliability.
Purpose of the Study:
- To investigate the stability and reliability of UCNP thermometry within living cells.
- To analyze the balance between nanoparticle confinement and laser-induced heating in optical trapping experiments.
- To understand the influence of the surrounding environment on UCNP optical properties for improved sensing and manipulation.
Main Methods:
- Utilized UCNPs for intracellular thermometry measurements under varying cytoplasmic conditions.
- Employed optical trapping techniques to study single UCNP behavior, including spectral changes and rotational dynamics.
- Investigated the impact of dopant concentration and laser power on trapping stability and thermal load.
Main Results:
- Intracellular chemical complexity (pH, ions, viscosity, crowding) can significantly alter UCNP emission, impacting thermometric accuracy.
- Optical trapping of UCNPs is challenged by modest forces and laser-induced heating, necessitating careful balancing of confinement and thermal effects.
- Single-particle measurements reveal insights into light-matter interactions and mechanical properties not observable in ensemble studies.
Conclusions:
- UCNPs show promise for nanoscale temperature and mechanical measurements but require careful consideration of environmental influences for quantitative applications.
- Optimizing UCNP performance in optical traps involves managing the trade-off between nanoparticle confinement and laser-induced heating.
- Further research into UCNP surface chemistry and environmental interactions is crucial for developing robust intracellular sensing and manipulation tools.
