Name: production of metal nanoparticles by pulsed laser-ablation in liquids: a tool for studying the antibacterial properties of nanoparticles
Uploaded: 2017-06-02T13:00:00
Description: Watch this Scientific Journal Video about Production of Metal Nanoparticles by Pulsed Laser-ablation in Liquids: A Tool for Studying the Antibacterial Properties of Nanoparticles at JoVE.com

This work was supported by the National Science Foundation (NSF awards CMMI-0922946 to D.B., CMMI-1300920 to D.B. and S.O'M., and CMMI-1531789 to S.O'M., D.B., and E.A.K.) and a Busch Biomedical Research Grant to E.A.K. and S.O'M.

1. Focusing the Nanosecond Laser and Measuring Fluence
<ol>
	<li>Assemble the ablation apparatus by placing a magnetic stir bar and a porous ablation stage inside a 50 mL glass beaker. 
	NOTE: The ablation stage consists of a 3.81 cm diameter, 1.6 mm thick stainless steel platform with ten 0.65 cm diameter holes and six 0.50 cm diameter holes drilled in the pattern illustrated in Figure 1. The purpose of these holes is to allow the liquid to move across the target so ...

<ol>
	<li>Amendola, V., Meneghetti, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=What+controls+the+composition+and+the+structure+of+nanomaterials+generated+by+laser+ablation+in+liquid+solution?.">What controls the composition and the structure of nanomaterials generated by laser ablation in liquid solution?.</a> Phys Chem Chem Phys. 15 (9), 3027-3046 (2013).</li><li>Anastas, P., Eghbali, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Green+chemistry:+principles+and+practice.">Green chemistry: principles and practice.</a> Chem Soc Rev. 39 (1), 301-312 (2010).</li><li>Mafune, F., Kohno, J. Y., Takeda, Y., Kondow, T., Sawabe, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+Gold+Nanoparticles+by+Laser+Ablation+in+Aqueous+Solution+of+Surfactant.">Formation of Gold Nanoparticles by Laser Ablation in Aqueous Solution of Surfactant.</a> J Phys Chem B. 105 (22), 5114-5120 (2001).</li><li>Rao, S. V., Podagatlapalli, G. K., Hamad, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrafast+laser+ablation+in+liquids+for+nanomaterials+and+applications.">Ultrafast laser ablation in liquids for nanomaterials and applications.</a> J Nanosci Nanotechnol. 14 (2), 1364-1388 (2014).</li><li>Tsuji, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+silver+nanoparticles+by+laser+ablation+in+polyvinylpyrrolidone+solutions.">Preparation of silver nanoparticles by laser ablation in polyvinylpyrrolidone solutions.</a> Appl Surf Sci. 254 (16), 5224-5230 (2008).</li><li>Zeng, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanomaterials+via+laser+ablation/irradiation+in+liquid:+a+review.">Nanomaterials via laser ablation/irradiation in liquid: a review.</a> Adv Funct Mater. 22 (7), 1333-1353 (2012).</li><li>Naddeo, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antibacterial+Properties+of+Nanoparticles:+A+Comparative+Review+of+Chemically+Synthesized+and+Laser-Generated+Particles.">Antibacterial Properties of Nanoparticles: A Comparative Review of Chemically Synthesized and Laser-Generated Particles.</a> Adv. Sci. Eng. Med. 7 (12), 1044-1057 (2015).</li><li>Elsayed, K. A., Imam, H., Ahmed, M. A., Ramadan, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+focusing+conditions+and+laser+parameters+on+the+fabrication+of+gold+nanoparticles+via+laser+ablation+in+liquid.">Effect of focusing conditions and laser parameters on the fabrication of gold nanoparticles via laser ablation in liquid.</a> Opt. &amp; Laser Tech. 45, 495-502 (2013).</li><li>Kabashin, A. V., Meunier, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+colloidal+nanoparticles+during+femtosecond+laser+ablation+of+gold+in+water.">Synthesis of colloidal nanoparticles during femtosecond laser ablation of gold in water.</a> J Appl Phys. 94 (12), 7941-7943 (2003).</li><li>Nichols, W. T., Sasaki, T., Koshizaki, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+ablation+of+a+platinum+target+in+water+I.+Ablation+mechanisms.">Laser ablation of a platinum target in water I. Ablation mechanisms.</a> J Appl Phys. 100 (11), 114911 (2006).</li><li>Povarnitsyn, M. E., Itina, T. E., Levashov, P. R., Khishchenko, K. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+nanoparticle+formation+by+ultra-short+laser+ablation+of+metals+in+liquid+environment.">Mechanisms of nanoparticle formation by ultra-short laser ablation of metals in liquid environment.</a> Phys Chem Chem Phys. 15 (9), 3108-3114 (2013).</li><li>Mortazavi, S. Z., Parvin, P., Reyhani, A., Golikand, A. N., Mirershadi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+Laser+Wavelength+at+IR+(1064+nm)+and+UV+(193+nm)+on+the+Structural+Formation+of+Palladium+Nanoparticles+in+Deionized+Water.">Effect of Laser Wavelength at IR (1064 nm) and UV (193 nm) on the Structural Formation of Palladium Nanoparticles in Deionized Water.</a> J Phys Chem C. 115 (12), 5049-5057 (2011).</li><li>Kim, J., Reddy, D. A., Ma, R., Kim, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+influence+of+laser+wavelength+and+fluence+on+palladium+nanoparticles+produced+by+pulsed+laser+ablation+in+deionized+water.">The influence of laser wavelength and fluence on palladium nanoparticles produced by pulsed laser ablation in deionized water.</a> Solid State Sci. 37, 96-102 (2014).</li><li>Mortazavi, S. Z., Parvin, P., Reyhani, A., Mirershadi, S., Sadighi-Bonabi, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+various+carbon+nanostructures+in+water+using+IR/UV+laser+ablation.">Generation of various carbon nanostructures in water using IR/UV laser ablation.</a> J Phys D: Appl Phys. 46 (16), 165303 (2013).</li><li>Hunter, B. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+active+mixed-metal+nanosheet+water+oxidation+catalysts+made+by+pulsed-laser+ablation+in+liquids.">Highly active mixed-metal nanosheet water oxidation catalysts made by pulsed-laser ablation in liquids.</a> J Am Chem Soc. 136 (38), 13118-13121 (2014).</li><li>Momma, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Short-pulse+laser+ablation+of+solid+targets.">Short-pulse laser ablation of solid targets.</a> Opt Commun. 129 (1), 134-142 (1996).</li><li>Sonntag, S., Roth, J., Gaehler, F., Trebin, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Femtosecond+laser+ablation+of+aluminium.">Femtosecond laser ablation of aluminium.</a> Appl Surf Sci. 255 (24), 9742-9744 (2009).</li><li>Yamashita, Y., Yokomine, T., Ebara, S., Shimizu, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heat+transport+analysis+for+femtosecond+laser+ablation+with+molecular+dynamics-two+temperature+model+method.">Heat transport analysis for femtosecond laser ablation with molecular dynamics-two temperature model method.</a> Fusion Eng Des. 81 (8), 1695-1700 (2006).</li><li>Zhigilei, L. V., Lin, Z., Ivanov, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atomistic+modeling+of+short+pulse+laser+ablation+of+metals:+connections+between+melting,+spallation,+and+phase+explosion.">Atomistic modeling of short pulse laser ablation of metals: connections between melting, spallation, and phase explosion.</a> J Phys Chem C. 113 (27), 11892-11906 (2009).</li><li>Schmidt, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lasers+in+Manufacturing+2011+-+Proceedings+of+the+Sixth+International+WLT+Conference+on+Lasers+in+Manufacturing+Metal+Ablation+with+Short+and+Ultrashort+Laser+Pulses.">Lasers in Manufacturing 2011 - Proceedings of the Sixth International WLT Conference on Lasers in Manufacturing Metal Ablation with Short and Ultrashort Laser Pulses.</a> Physics Procedia. 12, 230-238 (2011).</li><li>Azam, A., Ahmed, A. S., Oves, M., Khan, M. S., Memic, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Size-dependent+antimicrobial+properties+of+CuO+nanoparticles+against+Gram-positive+and-negative+bacterial+strains.">Size-dependent antimicrobial properties of CuO nanoparticles against Gram-positive and-negative bacterial strains.</a> Int. J. Nanomed. 7, 3527-3535 (2012).</li><li>Ivask, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Size-dependent+toxicity+of+silver+nanoparticles+to+bacteria,+yeast,+algae,+crustaceans+and+mammalian+cells+in+vitro.">Size-dependent toxicity of silver nanoparticles to bacteria, yeast, algae, crustaceans and mammalian cells in vitro.</a> PLoS One. 9 (7), e102108 (2014).</li><li>Kim, T. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Size-dependent+cellular+toxicity+of+silver+nanoparticles.">Size-dependent cellular toxicity of silver nanoparticles.</a> J Biomed Mater Res A. 100 (4), 1033-1043 (2012).</li><li>Raghupathi, K. R., Koodali, R. T., Manna, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Size-dependent+bacterial+growth+inhibition+and+mechanism+of+antibacterial+activity+of+zinc+oxide+nanoparticles.">Size-dependent bacterial growth inhibition and mechanism of antibacterial activity of zinc oxide nanoparticles.</a> Langmuir. 27 (7), 4020-4028 (2011).</li><li>Plech, A., Kotaidis, V., Gresillon, S., Dahmen, C., von Plessen, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser-induced+heating+and+melting+of+gold+nanoparticles+studied+by+time-resolved+x-ray+scattering.">Laser-induced heating and melting of gold nanoparticles studied by time-resolved x-ray scattering.</a> Phys Rev B. 70 (19), 195423 (2004).</li><li>Takami, A., Kurita, H., Koda, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser-Induced+Size+Reduction+of+Noble+Metal+Particles.">Laser-Induced Size Reduction of Noble Metal Particles.</a> J Phys Chem B. 103 (8), 1226-1232 (1999).</li><li>Kamat, P. V., Flumiani, M., Hartland, G. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Picosecond+Dynamics+of+Silver+Nanoclusters.+Photoejection+of+Electrons+and+Fragmentation.">Picosecond Dynamics of Silver Nanoclusters. Photoejection of Electrons and Fragmentation.</a> J Phys Chem B. 102 (17), 3123-3128 (1998).</li><li>Yamada, K., Tokumoto, Y., Nagata, T., Mafune, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanism+of+laser-induced+size-reduction+of+gold+nanoparticles+as+studied+by+nanosecond+transient+absorption+spectroscopy.">Mechanism of laser-induced size-reduction of gold nanoparticles as studied by nanosecond transient absorption spectroscopy.</a> J Phys Chem B. 110 (24), 11751-11756 (2006).</li><li>Pecora, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+Light+Scattering+Measurement+of+Nanometer+Particles+in+Liquids.">Dynamic Light Scattering Measurement of Nanometer Particles in Liquids.</a> J. Nanoparticle Res. 2 (2), 123-131 (2000).</li><li>Pyrz, W. D., Buttrey, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Particle+size+determination+using+TEM:+a+discussion+of+image+acquisition+and+analysis+for+the+novice+microscopist.">Particle size determination using TEM: a discussion of image acquisition and analysis for the novice microscopist.</a> Langmuir. 24 (20), 11350-11360 (2008).</li><li>Ratti, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Irradiation+with+visible+light+enhances+the+antibacterial+toxicity+of+silver+nanoparticles+produced+by+laser+ablation.">Irradiation with visible light enhances the antibacterial toxicity of silver nanoparticles produced by laser ablation.</a> Appl Phys A. 122 (4), 1-7 (2016).</li><li>Sajti, C. L., Sattari, R., Chichkov, B. N., Barcikowski, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gram+Scale+Synthesis+of+Pure+Ceramic+Nanoparticles+by+Laser+Ablation+in+Liquid.">Gram Scale Synthesis of Pure Ceramic Nanoparticles by Laser Ablation in Liquid.</a> J Phys Chem C. 114 (6), 2421-2427 (2010).</li><li>Streubel, R., Barcikowski, S., Gokce, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Continuous+multigram+nanoparticle+synthesis+by+high-power,+high-repetition-rate+ultrafast+laser+ablation+in+liquids.">Continuous multigram nanoparticle synthesis by high-power, high-repetition-rate ultrafast laser ablation in liquids.</a> Opt Lett. 41 (7), 1486-1489 (2016).</li><li>Streubel, R., Bendt, G., Gokce, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pilot-scale+synthesis+of+metal+nanoparticles+by+high-speed+pulsed+laser+ablation+in+liquids.">Pilot-scale synthesis of metal nanoparticles by high-speed pulsed laser ablation in liquids.</a> Nanotechnology. 27 (20), 205602 (2016).</li></ol>

Reproducible antimicrobial effects of NPs require consistent production of NPs with similar sizes and concentrations. Therefore, it is critical to standardize laser parameters including fluence, wavelength, and pulse duration. While dynamic light scattering is an easy and rapid method for estimating NP size, accurate quantification of the size distribution requires direct measurement by TEM. As each laser beam has distinct characteristics in terms of mode profile and divergence, it is critical to employ an empirical proc...

Nanoparticles (NPs) are generally defined as particles that have at least one dimension that is less than 100 nm in length. Traditional chemical NP synthesis methods typically require hazardous reducing agents, such as borohydrides and hydrazines. In contrast, laser ablation of solid metal targets immersed in a liquid medium (pulsed laser-ablation in liquids &#8211; PLAL) provides an environmentally friendly route for NP synthesis that satisfies all 12 of the Principles of Green Chemistry1,2. In PLAL, a submerged metal target is irradiated by repeated laser pulses. As the laser ablates the target, a dense plume of atomic clusters and vapor is released into the liquid medium wherein NPs rapidly coalesce. NPs produced by PLAL are finely dispersed in an aqueous medium and the size, polydispersity, and composition of the NPs can be easily controlled by varying the aqueous ablation liquid as well as laser parameters1,2,3,4,5,6.
Nanoparticle characteristics can be tuned by adjusting a number of laser parameters, including: fluence, wavelength, and pulse duration (reviewed in reference7). Laser fluence is calculated as the pulse energy divided by the area of the laser spot on the target surface. The precise effects of fluence on the size and polydispersity of NPs are somewhat controversial. In general, it has been shown that for &#39;long&#39; and &#39;ultra-short&#39; pulsed laser systems there are low and high fluence regimes that produce negative and positive trends in size, respectively8,9,10,11. NP size distributions can be empirically measured using techniques such as dynamic light scattering and transmission electron microscopy (TEM), as described below.
The choice of laser wavelength can affect the physical mechanisms by which the NPs are formed. At shorter (ultraviolet) wavelengths, high energy photons are capable of breaking interatomic bonds12. This mechanism of photo-ablation is an example of a top-down NP synthesis because it results in the release of ultra-small fragments of material which tend to produce larger more polydisperse samples upon quenching in the submersion liquid12,13,14. In contrast, near-infrared ablation (&#955; = 1,064 nm) yields a bottom-up synthesis mechanism dominated by plasma ablation12. Laser absorption by the target frees electrons that collide with, and subsequently free, bound electrons. As collisions increase, the material is ionized, thus igniting a plasma. The surrounding liquid confines the plasma, enhances its stability, and further increases absorption12. As the expanding plasma is quenched by the confining liquid, NPs are condensed with various geometries4,12,15.
The choice of laser pulse duration can further impact the NP-formation process. Commonly used long-pulsed lasers, with pulse durations greater than a few picoseconds, include all milli, micro, nano and some picosecond pulsed lasers. In this pulse-width regime, the laser pulse duration is longer than the electron-phonon equilibration time, which is typically on the order of a few picoseconds4,16,17,18,19. This results in the leaking of energy into the surrounding ablation medium and the formation of NPs by thermal mechanisms such as thermionic emission, vaporization, boiling and melting1,20.
The antibacterial activity of NPs is strongly influenced by particle size21,22,23,24. In order to enhance size reduction and monodispersity, the NPs can be irradiated a second time using a laser of a wavelength near the surface plasmon resonance (SPR) of the NP. The incident laser radiation is absorbed by the NP through excitation of the SPR. Fragmentation of the NP may occur through either thermal evaporation25,26 or Coulomb explosion27,28. The photoexcitation raises the temperature of the NP above the melting point, resulting in the shedding of the outer layer of the particle. It has been shown that adding agents such as polyvinylpyrrolidone (PVP) or sodium dodecyl sulfate (SDS) to the solution can greatly enhance post-irradiation effects5. The impact of the addition of various solutes have been described in several reports1,4,6. The ease of manipulation of NP characteristics by PLAL affords a novel method to develop novel NP-based antimicrobials.

<table border="0" cellpadding="0" cellspacing="0" width="851">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Nanosecond Nd:YAG laser</td>
			<td style="width:184px;">Ekspla</td>
			<td style="width:119px;">NL303</td>
			<td style="width:279px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Motorized xy scanning stage</td>
			<td style="width:184px;">Standa</td>
			<td style="width:119px;">8MTF</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">UV-VIS spectrophotometer</td>
			<td style="width:184px;">Agilent</td>
			<td style="width:119px;">Cary 60</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Dynamic light scattering unit</td>
			<td style="width:184px;">Malvern</td>
			<td style="width:119px;">Zetasizer ZS 90</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Microbalance</td>
			<td style="width:184px;">Maktek</td>
			<td style="width:119px;">TM 400</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Transmission electron microscope</td>
			<td style="width:184px;">Zeiss</td>
			<td style="width:119px;">EM 902</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Silver foil target</td>
			<td style="width:184px;">Alfa Aesar</td>
			<td align="right" style="width:119px;">12127</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">250 mm focal length lens</td>
			<td style="width:184px;">Edmund Optics</td>
			<td style="width:119px;">69-624</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Copper TEM grids</td>
			<td style="width:184px;">Pacific Grid-Tech</td>
			<td style="width:119px;">Cu-400LD</td>
			<td>Lacey/thin film coated grid</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">E. coli MG1655</td>
			<td style="width:184px;">ATCC</td>
			<td align="right" style="width:119px;">47076</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Bacto-tryptone</td>
			<td style="width:184px;">BD Biosciences</td>
			<td align="right" style="width:119px;">211705</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Yeast extract</td>
			<td style="width:184px;">BD Biosciences</td>
			<td align="right" style="width:119px;">212750</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Sodium chloride</td>
			<td style="width:184px;">Fisher Scientific</td>
			<td style="width:119px;">BP3581</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Bacto-agar</td>
			<td style="width:184px;">BD Biosciences</td>
			<td align="right" style="width:119px;">214010</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Sodium dodecyl sulfate</td>
			<td style="width:184px;">Fisher Scientific</td>
			<td>BP166-100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Polyvinylpyrrolidone</td>
			<td style="width:184px;">Fisher Scientific</td>
			<td style="width:119px;">BP431-100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Stainless steel disc (for ablation stage)</td>
			<td style="width:184px;">Metal Remnants, Inc.</td>
			<td style="width:119px;">N/A</td>
			<td>1.5 inch diameter, 16 gauge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Beaker</td>
			<td style="width:184px;">Fisher Scientific</td>
			<td style="width:119px;">02-540G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Magnetic stir bar</td>
			<td style="width:184px;">Fisher Scientific</td>
			<td style="width:119px;">14-513-57</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Magnetic stir plate</td>
			<td style="width:184px;">Fisher Scientific</td>
			<td style="width:119px;">11-100-49SH</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Laser energy and power meter</td>
			<td style="width:184px;">Coherent</td>
			<td style="width:119px;">1098579</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Carbon tape</td>
			<td style="width:184px;">Shinto Chemitron Co. Ltd.</td>
			<td style="width:119px;">STR Tape</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Sonicating water bath</td>
			<td style="width:184px;">Branson</td>
			<td align="right" style="width:119px;">1510</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Air compressor</td>
			<td style="width:184px;">GMC</td>
			<td style="width:119px;">Syclone 3010</td>
			<td>For drying ablation target</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">75 mm focal length lens</td>
			<td style="width:184px;">Edmund Optics</td>
			<td style="width:119px;">34-096</td>
			<td>Focusing lens for post-irradiation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Quartz cuvette</td>
			<td style="width:184px;">Precision Cells Inc</td>
			<td style="width:119px;">21UV40</td>
			<td>50 mm light path (for post-irradiation)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Kanamycin</td>
			<td style="width:184px;">Fisher Scientific</td>
			<td>BP906-5</td>
			<td></td>
		</tr>
		<tr height="105">
			<td height="105" style="height:105px;width:269px;">Light microscope</td>
			<td style="width:184px;">Nikon</td>
			<td style="width:119px;">50i</td>
			<td style="width:279px;">This microscope is used to focus the laser on the ablation stage. This particular model is no longer available, but any light microscope with a 4X objective will work.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">CCD camera</td>
			<td style="width:184px;">AmScope</td>
			<td style="width:119px;">MT5000-CCD</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:269px;">Micrometer slide</td>
			<td style="width:184px;">Ted Pella</td>
			<td style="width:119px;">2280-70</td>
			<td></td>
		</tr>
	</tbody>
</table>

production of metal nanoparticles by pulsed laser-ablation in liquids: a tool for studying the antibacterial properties of nanoparticles

The emergence of multidrug-resistant bacteria is a global clinical concern leading some to speculate about our return to a "pre-antibiotics" era of medicine. In addition to efforts to identify novel small-molecule antimicrobial drugs, there has been great interest in the use of metal nanoparticles as coatings for medical devices, wound dressings, and consumer packaging, due to their antimicrobial properties. The wide variety of methods available for nanoparticle synthesis results in a broad spectrum of chemical and physical properties which can affect antibacterial efficacy. This manuscript describes the pulsed laser-ablation in liquids (PLAL) method to create nanoparticles. This approach allows for the fine tuning of nanoparticle size, composition, and stability using post-irradiation methods as well as the addition of surfactants or volume excluders. By controlling particle size and composition, a large range of physical and chemical properties of metal nanoparticles can be explored which may contribute to their antimicrobial efficacy thereby opening new avenues for antibacterial development.

Using silver targets, the laser parameters described above, and 60 mM SDS in the ablation liquid, silver NPs are generated with the characteristic UV-VIS absorbance at the SPR (Figure 2A). TEM and DLS measurements reveal a mean NP diameter of approximately 25 nm before post-irradiation (Figure 2B). Ablation of the silver target for 30 min typically yields an NP concentration of 200 &#181;g/mL. In assessing the antimicrobial toxic...

Watch this Scientific Journal Video about Production of Metal Nanoparticles by Pulsed Laser-ablation in Liquids: A Tool for Studying the Antibacterial Properties of Nanoparticles at JoVE.com

Production of Metal Nanoparticles by Pulsed Laser-ablation in Liquids: A Tool for Studying the Antibacterial Properties of Nanoparticles

The antimicrobial properties of metals such as copper and silver have been recognized for centuries. This protocol describes pulsed laser-ablation in liquids, a method of synthesizing metal nanoparticles that provides the ability to fine tune the properties of these nanoparticles to optimize their antimicrobial effects.

The emergence of multidrug-resistant bacteria is a global clinical concern leading some to speculate about our return to a "pre-antibiotics" era of ...

Research

JoVE Journal

Bioengineering

Fluorescent Nanoparticles for the Measurement of Ion Concentration in Biological Systems

Tightly regulated ion homeostasis throughout the body is necessary for the prevention of such debilitating states as dehydration.1 In contrast, rapid ion ...

Viral Nanoparticles for In vivo Tumor Imaging

Viral Nanoparticles for In vivo Tumor Imaging

The use of nanomaterials has the potential to revolutionize materials science and medicine. Currently, a number of different nanoparticles are being ...

Harmonic Nanoparticles for Regenerative Research

In this visualized experiment, protocol details are provided for in vitro labeling of human embryonic stem cells (hESC) with second harmonic generation ...

Biofunctionalized Prussian Blue Nanoparticles for Multimodal Molecular Imaging Applications

Multimodal, molecular imaging allows the visualization of biological processes at cellular, subcellular, and molecular-level resolutions using multiple, ...

In Situ Mapping of the Mechanical Properties of Biofilms by Particle-tracking Microrheology

In Situ Mapping of the Mechanical Properties of Biofilms by Particle-tracking Microrheology

Bacterial cells are able to form surface-attached biofilm communities known as biofilms by encasing themselves in extracellular polymeric substances ...

Solid Lipid Nanoparticles (SLNs) for Intracellular Targeting Applications

Solid Lipid Nanoparticles SLNs for Intracellular Targeting Applications

Nanoparticle-based delivery vehicles have shown great promise for intracellular targeting applications, providing a mechanism to specifically alter ...

Identification of Metal Oxide Nanoparticles in Histological Samples by Enhanced Darkfield Microscopy and Hyperspectral Mapping

Nanomaterials are increasingly prevalent throughout industry, manufacturing, and biomedical research. The need for tools and techniques that aid in the ...

Encapsulating Cytochrome c in Silica Aerogel Nanoarchitectures without Metal Nanoparticles while Retaining Gas-phase Bioactivity

Encapsulating Cytochrome c in Silica Aerogel Nanoarchitectures without Metal Nanoparticles while Retaining Gas-phase Bioactivity

Applications such as sensors, batteries, and fuel cells have been improved through the use of highly porous aerogels when functional compounds are ...

Synthesis of Multi-walled Carbon Nanotubes Modified with Silver Nanoparticles and Evaluation of Their Antibacterial Activities and Cytotoxic Properties

In this study, multi-walled carbon nanotubes (MWCNTs) were treated with an aqueous sulfuric acid solution to form an oxygen-based functional group. Silver ...

Catalytic Scavenging of Plant Reactive Oxygen Species In Vivo by Anionic Cerium Oxide Nanoparticles

Catalytic Scavenging of Plant Reactive Oxygen Species In Vivo by Anionic Cerium Oxide Nanoparticles

Reactive oxygen species (ROS) accumulation is a hallmark of plant abiotic stress response. ROS play&#160;a dual role in plants by acting as signaling ...