article · 01/09/2008
Optical trapping of coated microspheres
Résumé
In an optical trap, micron-sized dielectric particles are held by a tightly focused laser beam. The optical force on the particle is composed of an attractive gradient force and a destabilizing scattering force. We hypothesized that using anti-reflection-coated microspheres would reduce scattering and lead to stronger trapping. We found that homogeneous silica and polystyrene microspheres had a sharp maximum trap stiffness at a diameter of around 800 nm-the trapping laser wavelength in water-and that a silica coating on a polystyrene microsphere was a substantial improvement for larger diameters. In addition, we noticed that homogeneous spheres of a correct size demonstrated anti-reflective properties. Our results quantitatively agreed with Mie scattering calculations and serve as a proof of principle. We used a DNA stretching experiment to confirm the large linear range in detection and force of the coated microspheres and performed a high-force motor protein assay. These measurements show that the surfaces of the coated microspheres are compatible with biophysical assays. (c) 2008 Optical Society of America.
Citer cet article
Bormuth, V., Jannasch, A., Ander, M., van Kats, C.-M., van Blaaderen, A., Howard, J., & Schaeffer, E. (2008). Optical trapping of coated microspheres. Opt. Express, 16(18). https://doi.org/10.1364/OE.16.013831@article{Bormuth2008_138,
author = {Bormuth, Volker and Jannasch, Anita and Ander, Marcel and van Kats, Carlos M. and van Blaaderen, Alfons and Howard, Jonathon and Schaeffer, Erik},
year = {2008},
month = {9},
title = {Optical trapping of coated microspheres},
journal = {Opt. Express},
publisher = {OPTICAL SOC AMER},
volume = {16},
number = {18},
address = {2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA},
abstract = {In an optical trap, micron-sized dielectric particles are held by a tightly focused laser beam. The optical force on the particle is composed of an attractive gradient force and a destabilizing scattering force. We hypothesized that using anti-reflection-coated microspheres would reduce scattering and lead to stronger trapping. We found that homogeneous silica and polystyrene microspheres had a sharp maximum trap stiffness at a diameter of around 800 nm-the trapping laser wavelength in water-and that a silica coating on a polystyrene microsphere was a substantial improvement for larger diameters. In addition, we noticed that homogeneous spheres of a correct size demonstrated anti-reflective properties. Our results quantitatively agreed with Mie scattering calculations and serve as a proof of principle. We used a DNA stretching experiment to confirm the large linear range in detection and force of the coated microspheres and performed a high-force motor protein assay. These measurements show that the surfaces of the coated microspheres are compatible with biophysical assays. (c) 2008 Optical Society of America.},
url = {http://www.dx.doi.org/10.1364/OE.16.013831},
doi = {10.1364/OE.16.013831},
issn = {1094-4087},
}TY - JOUR
AU - Bormuth, Volker
AU - Jannasch, Anita
AU - Ander, Marcel
AU - van Kats, Carlos M.
AU - van Blaaderen, Alfons
AU - Howard, Jonathon
AU - Schaeffer, Erik
PY - 2008
DA - 2008/09/01
TI - Optical trapping of coated microspheres
JO - Opt. Express
VL - 16
IS - 18
PB - OPTICAL SOC AMER
SN - 1094-4087
AB - In an optical trap, micron-sized dielectric particles are held by a tightly focused laser beam. The optical force on the particle is composed of an attractive gradient force and a destabilizing scattering force. We hypothesized that using anti-reflection-coated microspheres would reduce scattering and lead to stronger trapping. We found that homogeneous silica and polystyrene microspheres had a sharp maximum trap stiffness at a diameter of around 800 nm-the trapping laser wavelength in water-and that a silica coating on a polystyrene microsphere was a substantial improvement for larger diameters. In addition, we noticed that homogeneous spheres of a correct size demonstrated anti-reflective properties. Our results quantitatively agreed with Mie scattering calculations and serve as a proof of principle. We used a DNA stretching experiment to confirm the large linear range in detection and force of the coated microspheres and performed a high-force motor protein assay. These measurements show that the surfaces of the coated microspheres are compatible with biophysical assays. (c) 2008 Optical Society of America.
DO - 10.1364/OE.16.013831
UR - http://www.dx.doi.org/10.1364/OE.16.013831
ER -