ナノシステム·イニシアチブミュンヘン（NIM）を介して、DFGによる高度な研究者グラントHYMEM、通ってSonderforschungsbereich（SFB1032）を通じて、ERCによる財政支援、プロジェクトA8が感謝して承諾されます。私たちは、博士アレクサンダーOhlinger、サポート、実りある議論のための博士ソルCARRETERO-パラシオスやスパNedevに感謝しています。

1。実験装置<ol><li>開口数（NA）と直立顕微鏡および暗視野オイル冷却器を使用= 1.2暗視野照明のために。粒子観察と捕獲のための100倍の倍率とNA = 1.0と水浸対物レンズを使用してください。ノープリウスの動きに追従するために10倍の倍率とNA = 0.2と空気の目的に使用します。 </li><li>直立顕微鏡に接続された1064 nmの連続波レーザーと光ピンセットのセットアップを使用してください。 （対物後の電力計で測定）は100mWに光トラップのレーザーパワーを設定します。 </li><li>光トラップとノープリウスの動きに金粒子の動きを検出し、映像にCMOS高速カメラやデジタル一眼レフ（DSLR）カメラを使用してください。 </li><li>カメラに入るのを防止するために、レーザノッチフィルタを使用する。 </li><li>対物レンズの後にレーザパワーを測定するパワーメータを使用する。 </li></ol> 2。サンプル調製</p&gt; <ol><li>顕微鏡用スライドガラス上の水滴（180μl）をピペット暗視野顕微鏡にサンプルを配置する。 </li><li>水滴に小さな水タンクからノープリウスをピペット。 </li><li>溶液中のノープリウスの動きを観察し、ビデオストリームを記録するために10倍の空気対物レンズを使用。 </li><li>ノープリウスで生成された流体の動きを観察する検出器として60ナノメートルの直径を有する金ナノ粒子を使用してください。約つの粒子が100×水浸対物レンズとの視野で見ることができるようになるので、水滴中に高度に希釈された粒子溶液5μlを加える</li></ol> 3。粒子追跡実験<ol><li>光ピンセットでトラップ1金ナノ粒子。このため、顕微鏡ステージを移動することによって溶液中に拡散されて、金ナノ粒子の近くに1064 nmのレーザートラッピングをもたらす。魅力的な光の力は、目の焦点に向けた金ナノ粒子を引っ張る電子レーザービーム。トラップされた粒子は、その位置を維持し、もはや、むしろ拡散されていません。 30秒間、50Hzのフレームレートでデジタル一眼レフカメラで捕捉されたナノ粒子のビデオストリームを取る。 </li><li>光ピンセットのレーザーをオフにして、トラップから金ナノ粒子を解放する。 </li><li>ビデオストリームの各フレームで光学的にトラップされた金粒子の位置を読み出しに粒子追跡プログラムを使用します。経時的に、粒子の位置のxyの高速フーリエ変換（FFT）は、周波数スペクトルを明らかにする。 注記：ここでは、自己形成 &#39;IGOR PRO&#39;コンピュータプログラムコードは、経時的及びFFT分析のためのxy平面での粒子の中心位置を分析した。 </li><li>自己書かれたIGORコードの代替として、映像中の粒子を追跡するための自​​由に利用できる「ビデオスポットトラッカー」プログラムを使用します。追跡データのフーリエ変換を実行するために、商用ソフトウェア「起源」を使用します。 <oL&gt; <li>オープンプログラムのビデオスポットトラッカー」にビデオファイルをドラッグします。 </li><li>ビデオストリームと関心が現れるの円形領域の最初の写真で見られる粒子をマウスでクリック。 </li><li> 「対称」を選択して、粒子の追跡を最適化するためにtopコマンドプロンプトウィンドウで「最適化」。 </li><li>マウスは、topコマンドプロンプトウィンドウに「ログイン」をクリックして、データを保存するフォルダを選択します。追跡データは、データスプレッドシートとして保存される。 </li><li>マウスは、追跡プログラムの左側のコマンドプロンプトウィンドウの「動画再生」をクリックし、ビデオのすべてのフレームが分析されるまで待ちます。 </li><li>プログラムを終了し、「起源」で保存されたデータのスプレッドシートを開きます。 「Y 1」と「Y 2」と、列の値を設定します。 </li><li> 「原点」データスプレッドシートの「X」などの各映像フレームの時間ステップを設定します。 </li><li>マークX-位置欄とtopコマンドプロンプトウィンドウに「データ解析」と「FFT」を選択することで、FFTを実行する。 y位置列の手順を繰り返します。 </li><li>周波数に対するx方向及びy方向に計算されたFFT信号の振幅をプロットする。 </li></ol></li></ol> 4。数値シミュレーション<ol><li>コンピュータプログラム「Mathematicaを &#39;を使用して60 nmの金粒子の分極率αを計算する。 <ol><li> ：式（1）桑田らによれば分極率を算出し16を使用 <img alt="式（1）" fo:content-width="3in" src="/files/ftp_upload/51502/51502eq1.jpg" width="300" /> （1） </li><li>金粒子、ナノ粒子の半径、および周囲の媒質の屈折率の波長依存性複合誘電関数：プログラムコードで、次の3つのパラメータを定義します。 </li></ol></li><li>電気の記述を使用Agayan らによると、集束ガウスビームのトリC電界分布17 60 nmの金粒子に作用する光学力を計算する。： <img alt="式2" fo:content-width="4in" src="/files/ftp_upload/51502/51502eq2.jpg" width="500" /> （2） <ol><li> 利用方程式（3） - （6）Agayan ら 17の両方を計算するために、勾配及び粒子に作用する力を散乱させる。 <img alt="式3" fo:content-width="3.5in" src="/files/ftp_upload/51502/51502eq3.jpg" width="350" /> （3） <img alt="式4" fo:content-width="3in" src="/files/ftp_upload/51502/51502eq4.jpg" width="300" /> （4） <img alt="式5" fo:content-width="5in" src="/files/ftp_upload/51502/51502eq5.jpg" width="500" /> （5） <img alt="式6" fo:content-width="3in" src="/files/ftp_upload/51502/51502eq6.jpg" width="300" /> （6） </li><li>プログラムコードは、レーザパワーのパラメータを定義し、開口数のobjective、およびナノ粒子の複雑な分極率。 </li><li>光トラップ中の金粒子に作用する全光力を計算するために、勾配力と散乱力をまとめる。 </li></ol></li><li>同時に「制御」を押して、シミュレーションを実行し、 &quot;Enter&quot;を。 </li></ol>

<ol>
	<li>Hellawell, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Biological indicators of freshwater pollution and environmental management. , (1986).</li><li>Diamond, J. M., Barbour, M. T., Stribling, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterizing+and+comparing+bioassessment+approaches+and+their+results:+A+perspective.">Characterizing and comparing bioassessment approaches and their results: A perspective.</a> Journal of the North American Benthological Society. 15, 713-727 (1996).</li><li>Carlisle, D. 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=The+quality+of+our+Nation&#8217;s+waters&#8212;Ecological+health+in+the+Nation&#8217;s+streams,+1993&#8211;2005.">The quality of our Nation&#8217;s waters&#8212;Ecological health in the Nation&#8217;s streams, 1993&#8211;2005.</a> U.S. Geological Survey Circular. 1391, (2013).</li><li>Boxhall, G. A., Defaye, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Global+diversity+of+copepods+(Crustacea+Copepoda)+in+freshwater.">Global diversity of copepods (Crustacea Copepoda) in freshwater.</a> Hydrobiologia. 595 (1), 195-207 (2008).</li><li>Ferdous, Z., Muktadir, A. K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Review:+Potentiality+of+Zooplankton+as+Bioindicator.">A Review: Potentiality of Zooplankton as Bioindicator.</a> American Journal of Applied Sciences. 6 (10), 1815-1819 (2009).</li><li>Andersen Borg, C. M., Bruno, E., Ki&#248;rboe, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Kinematics+of+Swimming+and+Relocation+Jumps+in+Copepod+Nauplii.">The Kinematics of Swimming and Relocation Jumps in Copepod Nauplii.</a> PLoS ONE. 7 (10), (2012).</li><li>Gilchrist, B. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+and+Form+of+the+Brine+Shrimp+Artemia+Salina.">Growth and Form of the Brine Shrimp Artemia Salina.</a> Journal of Zoology. 134 (2), 221-235 (1960).</li><li>Boone, E., Baas-Becking, L. G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Salt+Effects+on+Egga+and+Nauplii+of+Artemia+Salina+L.">Salt Effects on Egga and Nauplii of Artemia Salina L.</a> Journal of General Physiology. 14 (6), 453-763 (1931).</li><li>Drewes, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+investigations+of+hatching+in+brine+shrimp+cysts.">Quantitative investigations of hatching in brine shrimp cysts.</a> Association for Biology Laboratory Education. 27, 299-312 (2006).</li><li>Williams, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+model+of+rowing+propulsion+and+the+ontogeny+of+locomotion+in+Artemia+larvae.">A model of rowing propulsion and the ontogeny of locomotion in Artemia larvae.</a> Biological Bulletin. 187, 164-173 (1994).</li><li>Croghan, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Mechanism+of+Osmotic+Regulation+in+the+Artemia+Salina+(L.):+The+Physiology+of+the+Branchiae.">The Mechanism of Osmotic Regulation in the Artemia Salina (L.): The Physiology of the Branchiae.</a> Journal of Experimental Biology. 35, 234-242 (1958).</li><li>Ashkin, A., Dziedzic, J. M., Bjorkholm, J. E., Chu, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Observation+of+a+single-beam+gradient+force+optical+trap+for+dielectric+particles.">Observation of a single-beam gradient force optical trap for dielectric particles.</a> Optics Letters. 11 (5), 288-290 (1986).</li><li>Svoboda, 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=Optical+trapping+of+metallic+Rayleigh+particles.">Optical trapping of metallic Rayleigh particles.</a> Optics Letters. 19 (13), 930-932 (1994).</li><li>Hansen, P. M., Bhatia, V. K., Harrit, N., Oddershede, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expanding+the+Optical+Trapping+Range+of+Gold+Nanoparticles.">Expanding the Optical Trapping Range of Gold Nanoparticles.</a> Nano Letters. 5 (10), 1937-1942 (2005).</li><li>Ohlinger, A., Deak, A., Lutich, A. A., Feldmann, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optically+Trapped+Gold+Nanoparticle+Enables+Listening+at+the+Microscale.">Optically Trapped Gold Nanoparticle Enables Listening at the Microscale.</a> Physical Review Letters. 108 (1), (2012).</li><li>Kuwata, H., Tamaru, H., Esumi, K., Miyano, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resonant+light+scattering+particles:+Practical+analysis+beyond+Rayleigh+approximation.">Resonant light scattering particles: Practical analysis beyond Rayleigh approximation.</a> Applied Physics Letters. 83 (22), 4625-4628 (2003).</li><li>Agayan, R. R., Gittes, F., Kopelman, R., Schmidt, C. F. <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+near+resonance+absorption.">Optical trapping near resonance absorption.</a> Applied Optics. 41 (12), 2318-2327 (2002).</li><li>Klar, T., Perner, M., Grosse, S., von Plessen, G., Spirkl, W., Feldmann, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface-Plasmon+Resonances+in+Single+Metallic+Nanoparticles.">Surface-Plasmon Resonances in Single Metallic Nanoparticles.</a> Physical Review Letters. 80, 4249-4252 (1998).</li><li>Ohlinger, A., Nedev, S., Lutich, A. A., Feldmann, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optothermal+Escape+of+Plasmonically+Coupled+Silver+Nanoparticles+from+a+Three-Dimensional+Optical+Trap.">Optothermal Escape of Plasmonically Coupled Silver Nanoparticles from a Three-Dimensional Optical Trap.</a> Nano Letters. 11 (4), 1770-1774 (2011).</li><li>Urban, A. S., Lutich, A. A., Stefani, F. D., Feldmann, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+Printing+Single+Gold+Nanoparticles.+Nano+Letters.">Laser Printing Single Gold Nanoparticles. Nano Letters.</a> Nano Letters. 10 (12), 4794-4798 (2010).</li><li>Urban, A. S., Fedoru, K. M., Nedev, S., Lutich, A., Lohmueller, T., Feldmann, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shrink-to-fit+Plasmonic+Nanostructures.">Shrink-to-fit Plasmonic Nanostructures.</a> Advanced Optical Materials. 1 (2), 123-127 (2013).</li></ol>

著者は、彼らが競合する経済的利益を持っていないことを宣言します。

暗視野顕微鏡は、金属ナノ粒子の散乱断面積は、幾何学的断面積（cp.の図2A）18 を超えているため、光の回折限界以下の寸法を有する金ナノ粒子を可視化するための強力なツールである。ピンセット設定では、このアプローチは、さらに粒子間のプラズモンカップリングプラズモン共鳴周波数が15の赤方偏移を引き起こすためにのみ、単一または複数の金?...

化学的および生物学的指標に基づく水質評価は、水生生態系1-3の状態や環境条件に洞察を得るために基本的に重要である。水化学分析のための古典的な方法は、官能的性質又は物理化学的パラメータの決定に基づいている。生物学的指標は、他の一方で、その存在および生存能力、彼らは生物指標の典型的な例インチ起こる生態系のための環境条件や汚染物質の影響に関する洞察を提供することができますカイアシ類、小さな水の甲殻類のグループである動物種であるほぼすべての水の生息地4,5に記載されてい。水試料からのこれらの種の活性及び生存率を観察し、したがって生態系5の全体的な状態に関する情報を得るために使用することができる。ノープリウスと呼ばれているカイアシ類の幼虫は、そのアンテナのリズミカルなストロークを使用します（それぞれの幼虫がappendaの3組を持っている自分の頭領域におけるGES）は、水6で泳ぐ。これらのストロークの頻度と強度は、それによって、年齢、フィットネス、および動物7月10日の環境条件の直接的な指標である。これらの標本上の任意の調査は通常、直接ノープリウスのアンテナストロークを観察し、カウントすることにより、顕微鏡を用いて行われます。そのサイズ（〜100〜500ミクロン）11には、これは多くの場合、測定を行うために必要とするいずれか1つずつ、または基板への単一ノープリウスを修正する。 ここでは、超高感度検出器として、光学的にトラップされた金ナノ粒子を用いて水試料中カイアシ類幼虫の活性を観察するための新たなアプローチを実証する。光ピンセットは、通常、ピコニュートンの範囲12から14まで分子間力を加えるか、測定するための細かい実験ツールとして、多くのグループによって使用されています。さらに最近では、光ピンセットのための応用範囲は、音響振動を観察し、解決するために拡張されました光学トラップ15内に閉じ込められるナノおよびマイクロ粒子の動きを監視することにより、液体培地でのNTの変動。液体中に浸漬される粒子は、ブラウン運動に供される。光トラップの内側に、しかし、この運動は、部分的に強く、レーザ誘起勾配力によって減衰される。したがって、光トラップの剛性およびレーザ光の焦点内の粒子の局在は、レーザーパワーによって調整することができる。同時に、それはトラップポテンシャルに関する特性を明らかにするために、トラップ内の時間依存性の粒子運動を監視することにより、粒子と分子の相互作用を分析することが可能である。このアプローチにより、周波数、強度、及びその液体環境中で移動する物体によって生成された流体運動の方向をピックアップしてレンダリングする。我々は、この一般的な考えは必要条件ではなく、個々のノープリウスの運動の周波数スペクトルを得るために適用することができる方法を示して直接試料に干渉する。この実験的なアプローチは、非常に敏感な方法で水生標本の運動性行動の観察のための新しい一般的な概念が導入されています。生物指標種の観察のために、これは水の分析のための現在の方法論を展開することができ、健康や水生生態系の保全についての情報を得るために適用することができる。

<table border="0" cellpadding="0" cellspacing="0" width="874">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Microscope Zeiss Axio Scope.A1</td>
			<td style="width:127px;">Carl Zeiss</td>
			<td style="width:201px;">490035-0012-000</td>
			<td style="width:303px;">dark field illumination</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Water objective Achroplan</td>
			<td style="width:127px;">Carl Zeiss</td>
			<td style="width:201px;">440087</td>
			<td>100x magnification, NA=1.0</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Air objective Epiplan</td>
			<td style="width:127px;">Carl Zeiss</td>
			<td style="width:201px;">442934</td>
			<td>10x magnification, NA=0.2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Dark field oil condenser</td>
			<td style="width:127px;">Carl Zeiss</td>
			<td style="width:201px;">445323</td>
			<td>NA=1.2</td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:244px;">Cobolt Rumba CW 1064 nm DPSSL</td>
			<td style="width:127px;">Cobolt&#160;</td>
			<td style="width:201px;">1064-05-01-2000-500</td>
			<td>1064nm, CW, &#955;=1064nm, 2 Watt, TEM00</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:244px;">Beam expander</td>
			<td style="width:127px;">Edmund Optics</td>
			<td style="width:201px;"></td>
			<td>Part no. 1064 2-8X 64414</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">High Speed Camera Dimax HD</td>
			<td style="width:127px;">PCO. Germany</td>
			<td style="width:201px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Color Camera Canon EOS 500 D&#160;</td>
			<td style="width:127px;">Canon</td>
			<td></td>
			<td>FAQ-ID: 8201395700</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Notch filter StopLine 532/1064</td>
			<td style="width:127px;">Semrock</td>
			<td style="width:201px;">A11149-711265</td>
			<td>Part no. NF01-532U</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Water&#160;</td>
			<td style="width:127px;"></td>
			<td style="width:201px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Nauplius Artemia Salina</td>
			<td style="width:127px;"></td>
			<td style="width:201px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:244px;">Gold colloid</td>
			<td style="width:127px;">BBInternational</td>
			<td style="width:201px;">Batch 13741&#160;</td>
			<td>Diameter 60nm</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">MQMie Version 3.2&#160;</td>
			<td style="width:127px;">r. Michael Quinten</td>
			<td style="width:201px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Mathematica 8.0</td>
			<td style="width:127px;">Wolfram</td>
			<td style="width:201px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Comsol Multiphysics 4.0&#160;</td>
			<td style="width:127px;">COMSOL, Inc.</td>
			<td style="width:201px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

analyzing the movement of the nauplius 'artemia salina' by optical tracking of plasmonic nanoparticles

私たちは、光ピンセット、小さな水生生物の移動により発生する流体振動を解析するための高感度なツールを提供してもよい方法を示しています。光ピンセットによって保持され、単一の金ナノ粒子は、水サンプルにノープリウス幼生（ アルテミア·サリナ ）のリズミカルな運動を定量化するためのセンサとして使用されている。これは、ノープリウス活性の結果として、捕捉されたナノ粒子の時間依存性の変位を監視することによって達成される。ナノ粒子の位​​置のフーリエ解析を観察した種の動きに特徴的な周波数スペクトルが得られる。この実験は、それらを直接観察し、トラップされた粒子についての幼虫の位置に関する情報を得るために必要とせず、小さな水生幼虫の活性を測定し、特徴づけるため、このメソッドの機能を示しています。全体的に、このアプローチは、水生Eで見つかった特定の種の活力に洞察力を与えることができるcosystemおよび水試料を分析するための従来の方法の範囲を広げることができる。

実験装置の概略図を図1Aに示されている。暗視野構成では、光学的トラップ15における60nmの金粒子の変位を検出する必要がある。トラッピング用レーザ波長1064nm、検出器12,14の金粒子の安定な閉じ込めを保証するために選択される。顕微鏡のビームスプリッタは、対物レンズを通してトラッピングビームを集束するために使用され、ノッチフィルタは、実験の検出...

Watch this Scientific Journal Video about Analyzing the Movement of the Nauplius 'Artemia salina' by Optical Tracking of Plasmonic Nanoparticles at JoVE.com

Analyzing the Movement of the Nauplius &#039;Artemia salina&#039; by Optical Tracking of Plasmonic Nanoparticles

私たちは、水生生物の周波数の動きを調査し、特徴づけるためにプラズモニックナノ粒子の光学式トラッキングを使用しています。

「ノープリウスの動きを分析する<em&gt;アルテミア·サリナ</em&gt; &#39;プラズモニックナノ粒子の光学追跡することによって、

We demonstrate how optical tweezers may provide a sensitive tool to analyze the fluidic vibrations generated by the movement of small aquatic organisms. A ...

analyzing-movement-nauplius-artemia-salina-optical-tracking-plasmonic

Research

JoVE Journal

Engineering

Analyzing the Movement of the Nauplius 'Artemia salina' by Optical Tracking of Plasmonic Nanoparticles

10.4K ビュー.  Ludwig-Maximilians-Universität. 私たちは、水生生物の周波数の動きを調査し、特徴づけるためにプラズモニックナノ粒子の光学式トラッキングを使用しています。 

ビデオ: Analyzing the Movement of the Nauplius 'Artemia salina' by Optical Tracking of Plasmonic Nanoparticles

Fabricating Metamaterials Using the Fiber Drawing Method

Metamaterials are man-made composite materials, fabricated by assembling components much smaller than the wavelength at which they operate 1. They owe their electromagnetic properties to the structure of their constituents, instead of the atoms that compose them. For example, sub-wavelength metal wires can be arranged to possess an effective electric permittivity that is either positive or negative at a given frequency, in contrast to the metals themselves 2. This unprecedented control over the behaviour of light can potentially lead to a number of novel devices, such as invisibility cloaks 3, negative refractive index materials 4, and lenses that resolve objects below the diffraction limit 5. However, metamaterials operating at optical, mid-infrared and terahertz frequencies are conventionally made using nano- and micro-fabrication techniques that are expensive and produce samples that are at most a few centimetres in size 6-7. Here we present a fabrication method to produce hundreds of meters of metal wire metamaterials in fiber form, which exhibit a terahertz plasmonic response 8. We combine the stack-and-draw technique used to produce microstructured polymer optical fiber 9 with the Taylor-wire process 10, using indium wires inside polymethylmethacrylate (PMMA) tubes. PMMA is chosen because it is an easy to handle, drawable dielectric with suitable optical properties in the terahertz region; indium because it has a melting temperature of 156.6 &deg;C which is appropriate for codrawing with PMMA. We include an indium wire of 1 mm diameter and 99.99% purity in a PMMA tube with 1 mm inner diameter (ID) and 12 mm outside diameter (OD) which is sealed at one end. The tube is evacuated and drawn down to an outer diameter of 1.2 mm. The resulting fiber is then cut into smaller pieces, and stacked into a larger PMMA tube. This stack is sealed at one end and fed into a furnace while being rapidly drawn, reducing the diameter of the structure by a factor of 10, and increasing the length by a factor of 100. Such fibers possess features on the micro- and nano- scale, are inherently flexible, mass-producible, and can be woven to exhibit electromagnetic properties that are not found in nature. They represent a promising platform for a number of novel devices from terahertz to optical frequencies, such as invisible fibers, woven negative refractive index cloths, and super-resolving lenses.

Metamaterials at terahertz frequencies offer unique opportunities, but are challenging to fabricate in bulk. We adapt the fabrication procedure for microstructured polymer optical fibers to inexpensively fabricate metamaterials potentially on an industrial scale. We produce polymethylmethacrylate fibers containing ~10 &mu;m diameter indium wires separated by ~100 &mu;m, which exhibit a terahertz plasmonic response.

ファイバー描画法を用いたメタマテリアルの作製

Metamaterials are man-made composite materials, fabricated by assembling components much smaller than the wavelength at which they operate 1. They owe ...

工学

Optical Trapping of Nanoparticles

Optical trapping is a technique for immobilizing and manipulating small objects in a gentle way using light, and it has been widely applied in trapping and manipulating small biological particles. Ashkin and co-workers first demonstrated optical tweezers using a single focused beam1. The single beam trap can be described accurately using the perturbative gradient force formulation in the case of small Rayleigh regime particles1. In the perturbative regime, the optical power required for trapping a particle scales as the inverse fourth power of the particle size. High optical powers can damage dielectric particles and cause heating. For instance, trapped latex spheres of 109 nm in diameter were destroyed by a 15 mW beam in 25 sec1, which has serious implications for biological matter2,3.
A self-induced back-action (SIBA) optical trapping was proposed to trap 50 nm polystyrene spheres in the non-perturbative regime4. In a non-perturbative regime, even a small particle with little permittivity contrast to the background can influence significantly the ambient electromagnetic field and induce a large optical force. As a particle enters an illuminated aperture, light transmission increases dramatically because of dielectric loading. If the particle attempts to leave the aperture, decreased transmission causes a change in momentum outwards from the hole and, by Newton's Third Law, results in a force on the particle inwards into the hole, trapping the particle. The light transmission can be monitored; hence, the trap can become a sensor. The SIBA trapping technique can be further improved by using a double-nanohole structure.
The double-nanohole structure has been shown to give a strong local field enhancement5,6. Between the two sharp tips of the double-nanohole, a small particle can cause a large change in optical transmission, thereby inducing a large optical force. As a result, smaller nanoparticles can be trapped, such as 12 nm silicate spheres7 and 3.4 nm hydrodynamic radius bovine serum albumin proteins8. In this work, the experimental configuration used for nanoparticle trapping is outlined. First, we detail the assembly of the trapping setup which is based on a Thorlabs Optical Tweezer Kit. Next, we explain the nanofabrication procedure of the double-nanohole in a metal film, the fabrication of the microfluidic chamber and the sample preparation. Finally, we detail the data acquisition procedure and provide typical results for trapping 20 nm polystyrene nanospheres.

The following setup approach details low power optical trapping of dielectric nanoparticles using a double-nanohole in metal film.

ナノ粒子の光トラッピング

Optical trapping is a technique for immobilizing and manipulating small objects in a gentle way using light, and it has been widely applied in trapping ...

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information support1,2,3. In this context, metal nanowires are especially desirable for realizing dense routing networks4. A prerequisite to operate such shared nanowire-based platform relies on our ability to electrically contact individual metal nanowires and efficiently excite surface plasmon polaritons5 in this information support. In this article, we describe a protocol to bring electrical terminals to chemically-synthesized silver nanowires6 randomly distributed on a glass substrate7. The positions of the nanowire ends with respect to predefined landmarks are precisely located using standard optical transmission microscopy before encapsulation in an electron-sensitive resist. Trenches representing the electrode layout are subsequently designed by electron-beam lithography. Metal electrodes are then fabricated by thermally evaporating a Cr/Au layer followed by a chemical lift-off. The contacted silver nanowires are finally transferred to a leakage radiation microscope for surface plasmon excitation and characterization8,9. Surface plasmons are launched in the nanowires by focusing a near infrared laser beam on a diffraction-limited spot overlapping one nanowire extremity5,9. For sufficiently large nanowires, the surface plasmon mode leaks into the glass substrate9,10. This leakage radiation is readily detected, imaged, and analyzed in the different conjugate planes in leakage radiation microscopy9,11. The electrical terminals do not affect the plasmon propagation. However, a current-induced morphological deterioration of the nanowire drastically degrades the flow of surface plasmons. The combination of surface plasmon leakage radiation microscopy with a simultaneous analysis of the nanowire electrical transport characteristics reveals the intrinsic limitations of such plasmonic circuitry.

Silver nanowires can simultaneously transport electrons and optical information in the form of surface plasmons. A procedure is described here to realize such a shared circuitry and the limitations at propagating both information carriers are evaluated.

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information ...

Patterning via Optical Saturable Transitions - Fabrication and Characterization

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical Saturable Transitions (POST). In this technique the chemical properties of organic photochromic molecules that undergo single-photon reactions are exploited, enabling rapid top-down nanopatterning over large areas at low light intensities, thereby, allowing for the circumvention of the far-field diffraction barrier.4 Simple, cost-effective, high throughput and resolution alternatives to nanopatterning are being explored, such as, two-photon polymerization5,6, beam pen lithography (BPL)7, scanning electron beam lithography (SEBL), and focused ion beam (FIB) patterning. However, multi-photon approaches require high light intensities, which limit their potential for high throughput and offer low image contrast. Although, electron and ion beam lithographic processes offer increased resolution, the serial nature of the process is limited to slow writing speeds, which also prevents patterning of features over large areas. Beam-pen lithography is an approach towards parallel near-field optical lithography. However, the gap between the source of the beam and the surface of the photoresist needs to be controlled extremely precisely for good pattern uniformity and this is very challenging to accomplish for large arrays of beams. Patterning via Optical Saturable Transitions (POST) is an alternative optical nanopatterning technique for patterning sub-wavelength features1-3. Since this technique uses single photons instead of electrons, it is extremely fast and does not require high light intensities1-3, opening the door to massive parallelization.

We report that the diffraction limit of conventional optical lithography can be overcome by exploiting the transitions of organic photochromic derivatives induced by their photoisomerization at low light intensities.1-3 This paper outlines our fabrication technique and two locking mechanisms, namely: dissolution of one photoisomer and electrochemical oxidation.

光可飽和遷移を経由してパターニング - 作製と特性評価

This protocol describes the fabrication and characterization of nanostructures using a novel nanolithographic technique called Patterning via Optical ...

Experiments on Ultrasonic Lubrication Using a Piezoelectrically-assisted Tribometer and Optical Profilometer

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at a frequency above the acoustic range (20 kHz). As a solid-state technology, ultrasonic lubrication can be used where conventional lubricants are unfeasible or undesirable. Further, ultrasonic lubrication allows for electrical modulation of the effective friction coefficient between two sliding surfaces. This property enables adaptive systems that modify their frictional state and associated dynamic response as the operating conditions change. Surface wear can also be reduced through ultrasonic lubrication. We developed a protocol to investigate the dependence of friction force reduction and wear reduction on the linear sliding velocity between ultrasonically lubricated surfaces. A pin-on-disc tribometer was built which differs from commercial units in that a piezoelectric stack is used to vibrate the pin at 22 kHz normal to the rotating disc surface. Friction and wear metrics including effective friction force, volume loss, and surface roughness are measured without and with ultrasonic vibrations at a constant pressure of 1 to 4 MPa and three different sliding velocities: 20.3, 40.6, and 87 mm/sec. An optical profilometer is utilized to characterize the wear surfaces. The effective friction force is reduced by 62% at 20.3 mm/sec. Consistently with existing theories for ultrasonic lubrication, the percent reduction in friction force diminishes with increasing speed, down to 29% friction force reduction at 87 mm/sec. Wear reduction remains essentially constant (49%) at the three speeds considered.

We present a protocol for using a piezoelectrically-assisted tribometer and optical profilometer to investigate the dependence of ultrasonic wear and friction reduction on linear velocity, contact pressure, and surface properties.

圧電支援摩擦計と光プロフィルを用いた超音波潤滑の実験

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at ...

Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating

One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to neutral gold Au(0) by reducing agents, such as sodium citrate or sodium borohydride. The extension of this method to decorate iron oxide or similar nanoparticles with gold nanoparticles to create multifunctional hybrid Fe2O3-Au nanoparticles is straightforward. This approach yields fairly good control over Au nanoparticle dimensions and loading onto Fe2O3. Additionally, the Au metal size, shape, and loading can easily be tuned by changing experimental parameters (e.g., reactant concentrations, reducing agents, surfactants, etc.). An advantage of this procedure is that the reaction can be done in air or water, and, in principle, is amenable to scaling up. The use of such optically tunable Fe2O3-Au nanoparticles for hyperthermia studies is an attractive option as it capitalizes on plasmonic heating of gold nanoparticles tuned to absorb light strongly in the VIS-NIR region. In addition to its plasmonic effects, nanoscale Au provides a unique surface for interesting chemistries and catalysis. The Fe2O3 material provides additional functionality due to its magnetic property. For example, an external magnetic field could be used to collect and recycle the hybrid Fe2O3-Au nanoparticles after a catalytic experiment, or alternatively, the magnetic Fe2O3 can be used for hyperthermia studies through magnetic heat induction. The photothermal experiment described in this report measures bulk temperature change and nanoparticle solution mass loss as functions of time using infrared thermocouples and a balance, respectively. The ease of sample preparation and the use of readily available equipment are distinct advantages of this technique. A caveat is that these photothermal measurements assess the bulk solution temperature and not the surface of the nanoparticle where the heat is transduced and the temperature is likely to be higher.

Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating

We describe the synthesis and properties of multifunctional Fe2O3-Au nanoparticles produced by a wet chemical approach and investigate their photothermal properties using laser irradiation. The composite Fe2O3-Au nanoparticles retain the properties of both materials, creating a multifunctional structure with excellent magnetic and plasmonic properties.

多機能ハイブリッドのFe<sub&gt; 2</sub&gt; O<sub&gt; 3</sub&gt; -Auナノ粒子の効率的なプラズモニック暖房

One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to ...

Electroactive Polymer Nanoparticles Exhibiting Photothermal Properties

A method for the synthesis of electroactive polymers is demonstrated, starting with the synthesis of extended conjugation monomers using a three-step process that finishes with Negishi coupling. Negishi coupling is a cross-coupling process in which a chemical precursor is first lithiated, followed by transmetallation with ZnCl2. The resultant organozinc compound can be coupled to a dibrominated aromatic precursor to give the conjugated monomer. Polymer films can be prepared via electropolymerization of the monomer and characterized using cyclic voltammetry and ultraviolet-visible-near infrared (UV-Vis-NIR) spectroscopy. Nanoparticles (NPs) are prepared via emulsion polymerization of the monomer using a two-surfactant system to yield an aqueous dispersion of the polymer NPs. The NPs are characterized using dynamic light scattering, electron microscopy, and UV-Vis-NIR-spectroscopy. Cytocompatibility of NPs is investigated using the cell viability assay. Finally, the NP suspensions are irradiated with a NIR laser to determine their effectiveness as potential materials for photothermal therapy (PTT).

A protocol is presented for the synthesis and preparation of nanoparticles consisting of electroactive polymers.

電気活性ポリマーナノ粒子出展光熱プロパティ

A method for the synthesis of electroactive polymers is demonstrated, starting with the synthesis of extended conjugation monomers using a three-step ...

Use of Sacrificial Nanoparticles to Remove the Effects of Shot-noise in Contact Holes Fabricated by E-beam Lithography

Nano-patterns fabricated with extreme ultraviolet (EUV) or electron-beam (E-beam) lithography exhibit unexpected variations in size. This variation has been attributed to statistical fluctuations in the number of photons/electrons arriving at a given nano-region arising from shot-noise (SN). The SN varies inversely to the square root of a number of photons/electrons. For a fixed dosage, the SN is larger in EUV and E-beam lithographies than for traditional (193 nm) optical lithography. Bottom-up and top-down patterning approaches are combined to minimize the effects of shot noise in nano-hole patterning. Specifically, an amino-silane surfactant self-assembles on a silicon wafer that is subsequently spin-coated with a 100 nm film of a PMMA-based E-beam photoresist. Exposure to the E-beam and the subsequent development uncover the underlying surfactant film at the bottoms of the holes. Dipping the wafer in a suspension of negatively charged, citrate-capped, 20 nm gold nanoparticles (GNP) deposits one particle per hole. The exposed positively charged surfactant film in the hole electrostatically funnels the negatively charged nanoparticle to the center of an exposed hole, which permanently fixes the positional registry. Next, by heating near the glass transition temperature of the photoresist polymer, the photoresist film reflows and engulfs the nanoparticles. This process erases the holes affected by SN but leaves the deposited GNPs locked in place by strong electrostatic binding. Treatment with oxygen plasma exposes the GNPs by etching a thin layer of the photoresist. Wet-etching the exposed GNPs with a solution of I2/KI yields uniform holes located at the center of indentations patterned by E-beam lithography. The experiments presented show that the approach reduces the variation in the size of the holes caused by SN from 35% to below 10%. The method extends the patterning limits of transistor contact holes to below 20 nm.

Uniformly sized nanoparticles can remove fluctuations in contact hole dimensions patterned in poly(methyl methacrylate) (PMMA) photoresist films by electron beam (E-beam) lithography. The process involves electrostatic funneling to center and deposit nanoparticles in contact holes, followed by photoresist reflow and plasma- and wet-etching steps.

犠牲ナノ粒子の使用は、電子ビームリソグラフィにより作製したコンタクトホール内にショットノイズの影響を除去します

Nano-patterns fabricated with extreme ultraviolet (EUV) or electron-beam (E-beam) lithography exhibit unexpected variations in size. This variation has ...

Plasmonic Trapping and Release of Nanoparticles in a Monitoring Environment

Plasmonic tweezers use surface plasmon polaritons to confine polarizable nanoscale objects. Among the various designs of plasmonic tweezers, only a few can observe immobilized particles. Moreover, a limited number of studies have experimentally measured the exertable forces on the particles. The designs can be classified as the protruding nanodisk type or the suppressed nanohole type. For the latter, microscopic observation is extremely challenging. In this paper, a new plasmonic tweezer system is introduced to monitor particles, both in directions parallel and orthogonal to the symmetric axis of a plasmonic nanohole structure. This feature enables us to observe the movement of each particle near the rim of the nanohole. Furthermore, we can quantitatively estimate the maximal trapping forces using a new fluidic channel.

A microchip fabrication process that incorporates plasmonic tweezers is presented here. The microchip enables the imaging of a trapped particle to measure maximal trapping forces.

監視環境でのプラズモニックトラッピングとナノ粒子の放出

Plasmonic tweezers use surface plasmon polaritons to confine polarizable nanoscale objects. Among the various designs of plasmonic tweezers, only a few ...

Microfluidic Imaging Flow Cytometry by Asymmetric-detection Time-stretch Optical Microscopy (ATOM)

Scaling the number of measurable parameters, which allows for multidimensional data analysis and thus higher-confidence statistical results, has been the main trend in the advanced development of flow cytometry. Notably, adding high-resolution imaging capabilities allows for the complex morphological analysis of cellular/sub-cellular structures. This is not possible with standard flow cytometers. However, it is valuable for advancing our knowledge of cellular functions and can benefit life science research, clinical diagnostics, and environmental monitoring. Incorporating imaging capabilities into flow cytometry compromises the assay throughput, primarily due to the limitations on speed and sensitivity in the camera technologies. To overcome this speed or throughput challenge facing imaging flow cytometry while preserving the image quality, asymmetric-detection time-stretch optical microscopy (ATOM) has been demonstrated to enable high-contrast, single-cell imaging with sub-cellular resolution, at an imaging throughput as high as 100,000 cells/s. Based on the imaging concept of conventional time-stretch imaging, which relies on all-optical image encoding and retrieval through the use of ultrafast broadband laser pulses, ATOM further advances imaging performance by enhancing the image contrast of unlabeled/unstained cells. This is achieved by accessing the phase-gradient information of the cells, which is spectrally encoded into single-shot broadband pulses. Hence, ATOM is particularly advantageous in high-throughput measurements of single-cell morphology and texture &#8211; information indicative of cell types, states, and even functions. Ultimately, this could become a powerful imaging flow cytometry platform for the biophysical phenotyping of cells, complementing the current state-of-the-art biochemical-marker-based cellular assay. This work describes a protocol to establish the key modules of an ATOM system (from optical frontend to data processing and visualization backend), as well as the workflow of imaging flow cytometry based on ATOM, using human cells and micro-algae as the examples.

Microfluidic Imaging Flow Cytometry by Asymmetric-detection Time-stretch Optical Microscopy ATOM

This protocol describes the implementation of an asymmetric-detection time-stretch optical microscopy system for single-cell imaging in ultrafast microfluidic flow and its applications in imaging flow cytometry.

非対称検出時間ストレッチ光学顕微鏡（ATOM）によるマイクロ流体イメージングフローサイトメトリー

Scaling the number of measurable parameters, which allows for multidimensional data analysis and thus higher-confidence statistical results, has been the ...