We would also like to thank Xiaoyu Miao and Ben Wilson for developing the most of the methods described within. This work was funded by National Science Foundation (DBI 0454324) and the National Institute of Health (R21 EB005183) and by PHS NRSA T32 GM07270 from NIGMS to ECK.

1. Random Au Nanoparticle Array Fabrication 8,10,12,14
<ol>
	<li>The Au nanoparticle array is formed by first creating a template that is made of a dense layer of randomly adsorbed latex spheres with mean diameter of 454 nm. This is achieved by first evaporating gold on a glass coverslip to a thickness of 20 nm using chromium as the adhesion layer.</li>
	<li>The polystyrene sphere monolayer is then self-assembled by exposing the gold-coated substrate to a mixture of 1-ethyl-3-(3-dimethylaminopropyl) carbo...

<ol>
	<li>Jones, T. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Electromechanics of Particles. , (1995).</li><li>Ashkin, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+trapping+and+manipulation+of+neutral+particles+using+lasers.">Optical trapping and manipulation of neutral particles using lasers.</a> Proc. Natl. Acad. Sci. U.S.A. 94, 4853-4853 (1997).</li><li>Neuman, K. C., Chadd, E. H., Liou, G. F., Bergman, K., Block, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+photodamage+to+Escherichia+coli+in+optical+traps.">Characterization of photodamage to Escherichia coli in optical traps.</a> Biophys. J. 77, 2856-2856 (1999).</li><li>Chiou, P. C., Ohta, A. T., Wu, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Massively+parallel+manipulation+of+single+cells+and+microparticles+using+optical+images.">Massively parallel manipulation of single cells and microparticles using optical images.</a> Nature. 436, 370-370 (2005).</li><li>Hsu, H. Y., Ohta, A. T., Chiou, P. Y., Jamshidi, A., Nealea, S. L., Wua, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Phototransistor-based+optoelectronic+tweezers+for+dynamic+cell+manipulation+in+cell+culture+media.">Phototransistor-based optoelectronic tweezers for dynamic cell manipulation in cell culture media.</a> Lab Chip. 10, 165-172 (2010).</li><li>Righini, M., Ghenuche, P. S., Cherukulappurath, V., Myroshnychenko, F. J., Garcia de Abajo, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quidant+Nano-optical+Trapping+of+Rayleigh+Particles+Escherichia+coli+Bacteria+with+Resonant+Optical+Antennas.">Quidant Nano-optical Trapping of Rayleigh Particles Escherichia coli Bacteria with Resonant Optical Antennas.</a> Nano Letters. 9, 3387-3391 (2009).</li><li>Righini, M., Zelenina, A. S., Girard, C., Quidant, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Parallel+and+Selective+Trapping+in+a+Patterned+Plasmonic+Landscape.">Parallel and Selective Trapping in a Patterned Plasmonic Landscape.</a> Nature Physics. 3, 477-480 (2007).</li><li>Miao, X., Lin, L. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large+dielectrophoresis+force+and+torque+induced+by+localized+surface+plasmon+resonance+of+a+cap-shaped+Au+nanoparticle+array.">Large dielectrophoresis force and torque induced by localized surface plasmon resonance of a cap-shaped Au nanoparticle array.</a> Opt. Lett. 32, 295-297 (2007).</li><li>Wilson, B. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Manipulation of Nanoparticles and Biological Samples through Enhanced Optical Forces [dissertation]. , (2009).</li><li>Miao, X. Y., Wilson, B. K., Pun, S. H., Lin, L. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+manipulation+of+micron/submicron+sized+particles+and+biomolecules+through+plasmonics.">Optical manipulation of micron/submicron sized particles and biomolecules through plasmonics.</a> Optics Exp. 16, 13517-13525 (2008).</li><li>Wilson, B. K., Mentele, T., Bachar, S., Knouf, E., Bendoraite, A., Tewari, M., Pun, S. H., Lin, L. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanostructure-enhanced+laser+tweezers+for+efficient+trapping+and+alignment+of+particles.">Nanostructure-enhanced laser tweezers for efficient trapping and alignment of particles.</a> Optics. Exp. 18, 16005-16013 (2010).</li><li>Miao, X., Wilson, B. K., Cao, G., Pun, S. H., Lin, L. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trapping+and+Rotation+of+Nanowires+Assisted+by+Surface+Plasmons.">Trapping and Rotation of Nanowires Assisted by Surface Plasmons.</a> IEEE Journal of Selected Topics in Quantum Electronics. 15, 1515-1520 (2009).</li><li>Miao, X. Y., Lin, L. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trapping+and+manipulation+of+biological+particles+through+a+plasmonic+platform.">Trapping and manipulation of biological particles through a plasmonic platform.</a> IEEE Journal of Selected Topics in Quantum Electronics. 13, 1655-1662 (2007).</li><li>Miao, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Plasmonics for Micro/Nano Manipulation and Optofluidics [dissertation]. , (2008).</li></ol>

The significance of these methods of trapping is that they decrease the optical intensity necessary for sustained trapping from somewhere on the order of 103 &mu;W/&mu;m2 to somewhere on the order of 10 &mu;W/&mu;m2.10,11 The limitations on these techniques are that the gold nanoparticle array experiences heating issues that must be overcome. To overcome this issue, a 2D photonic crystal structure that is composed of a dielectric material can be used. Such a structure could the...

<table border="1">
<tr>
<td>Material Name</td>
<td>Type</td>
<td>Company</td>
<td>Catalog Number</td>
<td>Comment</td>
</tr>
<tr>
<td>Axio Imager Microscope</td>
<td>D1M</td>
<td>Zeiss</td>
<td>D1M</td>
<td>Zeiss Axio Imager.D1M</td>
</tr>
<tr>
<td>Microscope Objective</td>
<td>50x/0.55</td>
<td>Zeiss</td>
<td>&nbsp;</td>
<td>LD EC Epiplan - NEOFLUAR 50x/0.55 HD DIC</td>
</tr>
<tr>
<td>Zeiss Microscope Camera</td>
<td>AxioCam MRc</td>
<td>Zeiss</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Helium Neon Laser</td>
<td>35 mW</td>
<td>Research Electro-Optics</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Variable Attenuator</td>
<td>Continuously Variable ND</td>
<td>ThorLabs</td>
<td>NDC-100C-4M</td>
<td>For adjusting microscope intensity</td>
</tr>
<tr>
<td>Zeiss Filter Set</td>
<td>Filter Set #17</td>
<td>Zeiss</td>
<td>488017-9901-000</td>
<td>Filter Set #17</td>
</tr>
<tr>
<td>Microscope Slides</td>
<td>0.5 mm thickness</td>
<td>VWR</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>3T3 mouse cell nuclei</td>
<td>&nbsp;</td>
<td colspan="2">Fred Hutchinson Cancer Research Center</td>
<td>Store as cold as possible</td>
</tr>
<tr>
<td>Acridine Orange dye</td>
<td>&nbsp;</td>
<td colspan="2">Fred Hutchinson Cancer Research Center</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Bovine Serum Albumin</td>
<td>1 to 10 ration in PBS</td>
<td colspan="2">Fred Hutchinson Cancer Research Center</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>454 nm polystyrene latex spheres</td>
<td>&nbsp;</td>
<td> Polysciences, Inc.</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>carbodiimide hydrochloride (EDC)</td>
<td>1-ethyl-3-(3-dimethylaminopropyl)</td>
<td>G-Biosciences</td>
<td>BC25-1</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>gold (for deposition)</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Reflective ruled diffraction grating</td>
<td>&nbsp;</td>
<td>Edmund Optics</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
</tr>
<tr>
<td>Phosphate Buffered Saline (PBS)</td>
<td>Dulbecco&#x2019;s Phosphate-Buffered Saline (D-PBS) (1X)</td>
<td>Invitrogen</td>
<td>14190-144</td>
<td>&nbsp;</td>
</tr>
</table>

utilization of plasmonic and photonic crystal nanostructures for enhanced micro- and nanoparticle manipulation

A method to manipulate the position and orientation of submicron particles nondestructively would be an incredibly useful tool for basic biological research. Perhaps the most widely used physical force to achieve noninvasive manipulation of small particles has been dielectrophoresis(DEP).1 However, DEP on its own lacks the versatility and precision that are desired when manipulating cells since it is traditionally done with stationary electrodes. Optical tweezers, which utilize a three dimensional electromagnetic field gradient to exert forces on small particles, achieve this desired versatility and precision.2 However, a major drawback of this approach is the high radiation intensity required to achieve the necessary force to trap a particle which can damage biological samples.3 A solution that allows trapping and sorting with lower optical intensities are optoelectronic tweezers (OET) but OET's have limitations with fine manipulation of small particles; being DEP-based technology also puts constraint on the property of the solution.4,5
This video article will describe two methods that decrease the intensity of the radiation needed for optical manipulation of living cells and also describe a method for orientation control. The first method is plasmonic tweezers which use a random gold nanoparticle (AuNP) array as a substrate for the sample as shown in Figure 1. The AuNP array converts the incident photons into localized surface plasmons (LSP) which consist of resonant dipole moments that radiate and generate a patterned radiation field with a large gradient in the cell solution. Initial work on surface plasmon enhanced trapping by Righini et al and our own modeling have shown the fields generated by the plasmonic substrate reduce the initial intensity required by enhancing the gradient field that traps the particle.6,7,8 The plasmonic approach allows for fine orientation control of ellipsoidal particles and cells with low optical intensities because of more efficient optical energy conversion into mechanical energy and a dipole-dependent radiation field. These fields are shown in figure 2 and the low trapping intensities are detailed in figures 4 and 5. The main problems with plasmonic tweezers are that the LSP's generate a considerable amount of heat and the trapping is only two dimensional. This heat generates convective flows and thermophoresis which can be powerful enough to expel submicron particles from the trap.9,10 The second approach that we will describe is utilizing periodic dielectric nanostructures to scatter incident light very efficiently into diffraction modes, as shown in figure 6.11 Ideally, one would make this structure out of a dielectric material to avoid the same heating problems experienced with the plasmonic tweezers but in our approach an aluminum-coated diffraction grating is used as a one-dimensional periodic dielectric nanostructure. Although it is not a semiconductor, it did not experience significant heating and effectively trapped small particles with low trapping intensities, as shown in figure 7. Alignment of particles with the grating substrate conceptually validates the proposition that a 2-D photonic crystal could allow precise rotation of non-spherical micron sized particles.10 The efficiencies of these optical traps are increased due to the enhanced fields produced by the nanostructures described in this paper.

Watch this Scientific Journal Video about Utilization of Plasmonic and Photonic Crystal Nanostructures for Enhanced Micro- and Nanoparticle Manipulation at JoVE.com

Utilization of Plasmonic and Photonic Crystal Nanostructures for Enhanced Micro- and Nanoparticle Manipulation

Plasmonic tweezers and photonic crystal nanostructures are shown to produce useful enhancements in the efficiency and orientation control of optically trapping micro- and nano-particles.

A method to manipulate the position and orientation of submicron particles nondestructively would be an incredibly useful tool for basic biological ...

utilization-plasmonic-photonic-crystal-nanostructures-for-enhanced

Research

JoVE Journal

Bioengineering

12.2K visualizações.  University of Washington. Pinças plasmonic e nanoestruturas de cristal fotônico são mostradas para produzir melhorias útil no controle da eficiência e orientação dos opticamente prendendo micro e nano-partículas.