Share Email Print

Proceedings Paper

Improved antireflection coated microspheres for biological applications of optical tweezers
Author(s): Valentina Ferro; Aaron Sonnberger; Mohammad K. Abdosamadi; Craig McDonald; Erik Schäffer; David McGloin
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

The success of optical tweezers in cellular biology1 is in part due to the wide range of forces that can be applied, from femto- to hundreds of pico-Newtons; nevertheless extending the range of applicable forces to the nanoNewton regime opens access to a new set of phenomena that currently lie beyond optical manipulation.

A successful approach to overcome the conventional limits on trapping forces involves the optimization of the trapped probes. Jannasch et al.2 demonstrated that an anti-reflective shell of nanoporous titanium dioxide (aTiO2, nshell = 1.75) on a core particle made out of titanium dioxide in the anatase phase (cTiO2, ncore = 2.3) results in trappable microspheres capable to reach forces above 1 nN.

Here we present how the technique can be further improved by coating the high refractive index microspheres with an additional anti-reflective shell made out of silica (SiO2). This external shell not only improves the trap stability for microspheres of different sizes, but also enables the use of functionalization techniques already established for commercial silica beads in biological experiments.

We are also investigating the use of these new microspheres as probes to measure adhesion forces between intercellular adhesion molecule 1 (ICAM-1) and lymphocyte function-associated antigen 1 (LFA-1) in effector T-Cells and will present preliminary results comparing standard and high-index beads.

Paper Details

Date Published: 16 September 2016
PDF: 8 pages
Proc. SPIE 9922, Optical Trapping and Optical Micromanipulation XIII, 99222T (16 September 2016); doi: 10.1117/12.2239025
Show Author Affiliations
Valentina Ferro, Univ. of Dundee (United Kingdom)
Aaron Sonnberger, Eberhard Karls Univ. Tübingen (Germany)
Mohammad K. Abdosamadi, Eberhard Karls Univ. Tübingen (Germany)
Craig McDonald, Univ. of Dundee (United Kingdom)
Erik Schäffer, Eberhard Karls Univ. Tübingen (Germany)
David McGloin, Univ. of Dundee (United Kingdom)

Published in SPIE Proceedings Vol. 9922:
Optical Trapping and Optical Micromanipulation XIII
Kishan Dholakia; Gabriel C. Spalding, Editor(s)

© SPIE. Terms of Use
Back to Top