Manipulation of cells with laser microbeam scissors and optical tweezers: a review

Greulich, Karl Otto

doi:10.1088/1361-6633/80/2/026601

Cited by 38 publications

(51 citation statements)

References 157 publications

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“…The intense illumination at their focus and the freedom to manipulate objects make optical tweezers an ideal tool for spatially‐resolved, subwavelength photochemistry. Microsurgery is a prime example of it . Pioneered in 1991, the technique relies on a pair of lasers at different wavelengths.…”

Section: Fields Of Applicationmentioning

confidence: 99%

Nanoscale Optical Trapping: A Review

Bradac

2018

Advanced Optical Materials

113

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The First TrapIn 1969, a "back-of-the-envelope" calculation inspired Ashkin to conduct a simple experiment and determine whether it was feasible to use light radiation pressure to accelerate objects to practical speeds. Photons carry momentum hν/c (with h, ν and c being the Planck's constant, the frequency of the photon and the speed of light, respectively). If light from a source with power P shines on a mirror, P/hν photons hit the surface every second and transfer a total momentum of (2P/hν)(hν/c) = 2P/c onto it. A perfectly reflecting mirror should therefore-due to conservation-acquire an equal momentum in the same direction light propagates.Based on this crude calculation, Ashkin predicted that a light source of power P = 1 W, would produce a force (on an ideally reflecting mirror) of ≈10 nN-indeed small in absolute terms. [3] Nevertheless, if a laser beam is used as the light source and is focused on a spot of ≈1 µm 2 to hit a particle ≈1 µm in diame ter, the resulting force does become relevant. Assuming the particle is perfectly reflective and has a density of 1 g cm −3 , the calculated acceleration is ≈10 9 cm s −2 , i.e., roughly 10 6 times the acceleration of gravity. In the experiment, Ashkin conducted to test his hypotheses, [2] a cw argon laser (wavelength λ = 514.5 nm, waist radius w 0 = 6.2 µm at the focal point) was employed to accelerate latex spheres (diameter 0.59, 1.31, and 2.68 µm), which were freely suspended in water, in a glass chamber. With just milliwatts of laser power, Ashkin observed that the particles were pushed in the direction of the mildly focused Gaussian laser beam, with values for the acceleration consistent with his rough predictions. Interestingly, he also observed an unanticipated phenomenon. Particles located in the fringes of the beam were drawn toward the beam axiswhere the light intensity is the highest-before being accelerated and pushed with ≈µm s −1 speeds toward the back of the chamber. They would disperse by Brownian motion away from the beam axis once the laser was switched off, yet they would be drawn again toward the center of the beam upon turning the laser back on-as the radiation pressure had a transverse component to the force, as well as the predicted longitudinal one.The origin of both the transversal and longitudinal force is usually understood by considering two distinct regimes, depending on the relative size of the particles to the wavelength of the laser beam: the geometrical (ray optics) regime and the Rayleigh (dipole approximation) regime.Optical trapping is the craft of manipulating objects with light. Decades after its first inception in 1970, the technique has become a powerful tool for ultracold-atom physics and manipulation of micron-sized particles. Yet, optical trapping of objects at the intermediate-nanoscale-range is still beyond full grasp. This matters because the nanometric realm is where several promising advances, from mastering single-molecule experiments in biology, to fabricating hybrid devices for nanoelectronics and photonics, a...

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Section: Fields Of Applicationmentioning

confidence: 99%

Nanoscale Optical Trapping: A Review

Bradac

2018

Advanced Optical Materials

113

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“…No changes were found when the TNTs bearing no particles or bare FNDs were irradiated under the same conditions for more than 6min ( Figure S9 and Videos S3, S4). To obtain T m of the local heating, we took as hotgun approach by measuring the TNT membrane temperature (that is,r oom temperature + DT membrane )f or more than 10 GNR-FNDs situated close to the centers of the nanotubes at the same laser power (for example,330 mW) and simultaneously observing whether the heated TNTs ruptured/retracted or remained stable.W e intentionally kept the laser power low to avoid overheating of the TNTs as well as rupturing of the TNTs by radiation pressure [34] and other chemical, thermal, and mechanical effects via free electron generation. [35] Thes uccessful rate of such local heating was 20 %orless.W edetermined the TNT membrane temperature rise (DT membrane )f rom the measured DT FND and r according to Equation (1), and found that T m = 28 AE 2 8 8Cfor the GFP-transduced HEK293T cells (Figure 3e).…”

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confidence: 99%

Measuring Nanoscale Thermostability of Cell Membranes with Single Gold–Diamond Nanohybrids

et al. 2017

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Much of the current understanding of thermal effects in biological systems is based on macroscopic measurements. There is little knowledge about the local thermostability or heat tolerance of subcellular components at the nanoscale. Herein, we show that gold nanorod-fluorescent nanodiamond (GNR-FND) hybrids are useful as a combined nanoheater/nanothermometer in living cells. With the use of a 594 nm laser for both heating and probing, we measure the temperature changes by recording the spectral shifts of the zero-phonon lines of negatively charged nitrogen-vacancy centers in FNDs. The technique allows us to determine the rupture temperatures of individual membrane nanotubes in human embryonic kidney cells, as well as to generate high temperature gradients on the cell membrane for photoporation and optically controlled hyperthermia. Our results demonstrate a new paradigm for hyperthermia research and application.

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“…To obtain T m of the local heating, we took a shotgun approach by measuring the TNT membrane temperature (that is, room temperature+Δ T membrane ) for more than 10 GNR‐FNDs situated close to the centers of the nanotubes at the same laser power (for example, 330 μW) and simultaneously observing whether the heated TNTs ruptured/retracted or remained stable. We intentionally kept the laser power low to avoid overheating of the TNTs as well as rupturing of the TNTs by radiation pressure and other chemical, thermal, and mechanical effects via free electron generation . The successful rate of such local heating was 20 % or less.…”

Section: Figurementioning

confidence: 96%

Measuring Nanoscale Thermostability of Cell Membranes with Single Gold–Diamond Nanohybrids

et al. 2017

View full text Add to dashboard Cite

Much of the current understanding of thermal effects in biological systems is based on macroscopic measurements. There is little knowledge about the local thermostability or heat tolerance of subcellular components at the nanoscale. Herein, we show that gold nanorod–fluorescent nanodiamond (GNR‐FND) hybrids are useful as a combined nanoheater/nanothermometer in living cells. With the use of a 594 nm laser for both heating and probing, we measure the temperature changes by recording the spectral shifts of the zero‐phonon lines of negatively charged nitrogen‐vacancy centers in FNDs. The technique allows us to determine the rupture temperatures of individual membrane nanotubes in human embryonic kidney cells, as well as to generate high temperature gradients on the cell membrane for photoporation and optically controlled hyperthermia. Our results demonstrate a new paradigm for hyperthermia research and application.

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Manipulation of cells with laser microbeam scissors and optical tweezers: a review

Cited by 38 publications

References 157 publications

Nanoscale Optical Trapping: A Review

Nanoscale Optical Trapping: A Review

Measuring Nanoscale Thermostability of Cell Membranes with Single Gold–Diamond Nanohybrids

Measuring Nanoscale Thermostability of Cell Membranes with Single Gold–Diamond Nanohybrids

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