Nanojet Trapping of a Single Sub-10 nm Upconverting Nanoparticle in the Full Liquid Water Temperature Range

• Upconverting nanoparticles (UCNPs) have been used as optical probes in a great variety of scenarios ranging from cells to animal models. When optically trapped, a single UCNP can be remotely manipulated making possible, for instance, thermal scanning in the surroundings of a living cell. When conventional optics is used, the stability of an optically trapped UCNP is very limited. Its reduced size leads to optical potentials comparable to thermal energy, and up to now, stable optical trapping of a UCNP has been demonstrated only close to room temperature. This fact limits their use above room temperature, for instance, the use to investigate protein denaturalization that occurs in the 40–50 °C range. In this work, stable optical trapping of a single UCNP in the 20–90 °C range has been demonstrated by using a photonic nanojet. The use of an optically trapped microsphere makes it possible to overcome the diffraction limit producing another optical trap of smaller size and enhanced strength. This simple strategy leads not only to an improvement in the thermal stability of the optical trap but also to an enhancement of the emission intensity generated by the optically trapped UCNP. 

Ämnesord

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

Nyckelord

nanoparticles

optical trapping

photonic nanojet

thermal stability

upconversion

Diffraction

Thermodynamic stability

Animal model

Diffraction limits

Emission intensity

Optical potential

Optical probe

Opticaltrapping

Upconverting nanoparticles

nanoparticle

water

animal

optical tweezers

photon

temperature

Animals

Photons

Publikations- och innehållstyp

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art (ämneskategori)