This work was supported by the Air Force Office of Scientific Research Young Investigator Research Program (AFOSR, Grant. No. FA9550-15-1-0301).

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The authors declare that they have no competing financial interests.

銀ナノキューブは、化学的に以前に報告された合成法と同様の反応条件を用いて合成した。2,12,17-20この合成は、50〜100nmの範囲の辺の長さを有するナノキューブの製造を可能にします。例えば、2.5時間の典型的な加熱時間は、〜75nmでの辺の長さを有するナノキューブをもたらします。より長い合成時間（&gt; 3時間）がしかし、これはまた、短縮型ナ​​ノキューブまたは八面体のような異なる形状になることがあり、より大きなナノ粒子をもたらします。最終的な溶液を遠心分離し、脱イオン水に再懸濁し、そしてプラズモン共鳴散乱スペクトルにおいて顕著な変化なしに4℃で冷蔵庫で少なくとも1ヶ月間保存することができる。12 上記のプロトコルで提示プロセスからのAgナノ立方体の大きさや形状はRBF、そのキャップと攪拌子の洗浄だけでなく、EG液の品質に非常に敏感です。 Nanopartiこのような丸いまたは細長いナノ粒子のような形状の異なるクルは、おそらく合成におけるこれらのステップの1に問題があるという印です。したがって、1.1.1-1.1.4と1.2.1-1.2.2が非常に重要であるステップことをお勧めします。 単一nanopatchアンテナから収集した散乱スペクトルを図4bに650nmで強いプラズモン共鳴を示すが示されています。このような共振は、銀ナノキューブ、高品質のナノキューブによって可能となるAu膜との間のギャップ領域に優れたモード閉じ込めを示します。さらに、このようなスペクトルを得るために、それはまた、サンプルがクリーンであることが要求され、スペーサ層（PE層）は、均一な厚さを有しており、下層のAu膜が平滑です。強いプラズモン共鳴は、さらに、個々のnanopatchアンテナは暗視野像及び大きな蛍光図4Dに観察することができ、図4cに示されたデータによって確認されます増強は、ギャップ領域に位置するのCy5分子の観察されます。また、空気にさらされ、したがって、光学的測定は、サンプルが用意されている日に、または1〜3日以内に行われるべきであることが推奨されたときのAgナノキューブはPVPコーティングにもかかわらず、時間の経過とともに酸化していることに留意すべきです。酸化を最小限にするために、nanopatchアンテナサンプルは真空または窒素ガス中で保存されることをお勧めします。 本論文で提示された方法は、コロイド合成とレイヤーバイレイヤーディップコーティングプロセスを利用して、よく制御された寸法とするAgナノキューブとプラズモニックnanopatchアンテナの製造を可能にします。ナノ粒子の狭いサイズ分布を生成しながら、光学又は電子ビームリソグラフィのような他の技術と比較して、ここに提示技術は、低コスト、大規模生産のための可能性を提供します。 本論文でプラズモニックnanopatchアンテナはまたのための偉大な約束を保持しますデザインによる新たなナノ物質は、それらの巨視的な対応には存在しないかもしれないユニークな特性を示します。特に、これらのナノアンテナ30,000を超える埋め込 ​​まれた色素分子の過去最高蛍光増強を示した。千の12自然放出率の強化。超自然放出及び高い量子収率。13,14に加えて、エミッタはこれらnanopatchアンテナ外部の検出器または単一モードファイバへの結合が必要とされる用途のために重要である展示高指向性放出に結合することが示されています。ナノスケールのパッチアンテナの将来のアプリケーションは、発光ダイオードなどの超高速光電子デバイス、より高効率の光検出器及び光起電デバイス、センシング及び量子情報処理技術の範囲であり得る。12-14

近年では、コロイド状ナノ粒子の合成と高度な構造にこれらのアセンブリは、両方の研究と産業の発展に大きな関心を集めている。ナノ粒子の1-4コロイド合成は、優れたサイズの均一性、低コストなどを含むリソグラフィーで作製したナノ構造体の上にいくつかの利点を持っています大規模並列生産の可能性。 このような銀（Ag）及び金（Au）などの金属ナノ粒子は、局在表面プラズモンポラリトンをサポートし、回折限界よりもはるかに小さい体積に光を閉じ込める機能を有することができる。1,3-5生じる高電界強度を高めるローカルに作成光と物質の相互作用を可能にする状態密度は、ナノスケールで調整することができます。最近の努力は、三角形を含むサイズおよび形状の広い範囲でAg及びAuのナノ粒子を合成するための手順、4,6-ケージ、3,4及びロッドを実証していますここで説明するナノキューブに加えて、4,7,8。いくつかのAgやAuのnanocomponentsで構成されるナノ構造も合わせ特性を実証製作されてきた。1,9-11 ここでは、プラズモニックnanopatchアンテナを形成するために、基礎となるAu膜とこれらのAgナノキューブのカップルに、もっと重要なのAgナノキューブとを合成するための手順を示しています。銀ナノキューブとAu膜との間の距離は、高分子電解質スペーサ層の系列を用いて、約1 nmの分解能で制御することができます。また、プラズモニックnanopatchアンテナには、このような有機色素として、活性媒質を組み込む方法を示しています。ナノキューブとAu膜との間にギャップ領域で強く閉じ込められた電磁界のため、nanopatchアンテナが埋め込 ​​まれた色素分子の高度に強化された蛍光及び自然放出のために使用することができる。本論文で12,13方法が一般化することができます。他のエミッタに、SUCコロイド固体量子ドット14または二次元半導体材料15およびプラズモン共鳴ナノキューブの大きさや間隔を変えることにより、広いスペクトル範囲にわたって調整することができるように、H。

<table>
	<tbody>
		<tr>
			<td>Reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ethylene glycol&#160;</td>
			<td>J.T. Baker</td>
			<td>9300</td>
			<td>Must be anhydrous</td>
		</tr>
		<tr>
			<td>Sodium hydrosulfide hydrate&#160;&#160;</td>
			<td>Sigma Aldrich</td>
			<td>161527</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly vinylpyrrolidone&#160;</td>
			<td>Sigma Aldrich</td>
			<td>856568</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrochroric acid BDH ARISTAR PLUS</td>
			<td>VWR International</td>
			<td>7647-01-0</td>
			<td></td>
		</tr>
		<tr>
			<td>Silver trifluoroacetate&#160;</td>
			<td>Sigma Aldrich</td>
			<td>482307</td>
			<td>Store in dark place</td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Sigma Aldrich</td>
			<td>48358</td>
			<td></td>
		</tr>
		<tr>
			<td>Nitric acid&#160;</td>
			<td>Sigma Aldrich</td>
			<td>7697-37-2</td>
			<td>&#160;concentrated (70%), for cleaning</td>
		</tr>
		<tr>
			<td>Poly(allylamine) hydrochloride (PAH)</td>
			<td>Sigma-Aldrich</td>
			<td>283215</td>
			<td></td>
		</tr>
		<tr>
			<td>Polystyrene sulfonate&#160; (PSS)</td>
			<td>Sigma-Aldrich</td>
			<td>561223</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Chloride&#160;</td>
			<td>Macron Inc.</td>
			<td>7647</td>
			<td></td>
		</tr>
		<tr>
			<td>Sulfo-Cyanine5 carboxylic acid (Cy5)</td>
			<td>Lumiprobe</td>
			<td>13390</td>
			<td>Fluorescent dye (molecular weight: 664.76 g/mol)</td>
		</tr>
		<tr>
			<td>Equipments</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Stirring hotplate with temperature control</td>
			<td>VWR International</td>
			<td>89000-338</td>
			<td></td>
		</tr>
		<tr>
			<td>Vortex mixers</td>
			<td>VWR International</td>
			<td>10153-834</td>
			<td></td>
		</tr>
		<tr>
			<td>Microcentrifuge</td>
			<td>Thermoscientific</td>
			<td>Model 59A</td>
			<td></td>
		</tr>
		<tr>
			<td>Silicone fluid&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>63148-62-9</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro-scale</td>
			<td>Mettler Toledo</td>
			<td>Model ML 104/03</td>
			<td></td>
		</tr>
		<tr>
			<td>Electron-beam metal evaporator&#160;</td>
			<td>CHA Industries</td>
			<td>E-beam evaporator</td>
			<td>Located inside a clean room</td>
		</tr>
		<tr>
			<td>Pre-cleaned glass slides</td>
			<td>Schott North America, Inc.</td>
			<td>Nexterion Glass B&#160;</td>
			<td>Clean room pre-cleaned</td>
		</tr>
		<tr>
			<td>25-mL 24/40 round-bottle flask&#160;</td>
			<td>VWR International</td>
			<td>60002-290</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnetic stirring bar</td>
			<td>VWR International</td>
			<td>58948-116</td>
			<td></td>
		</tr>
		<tr>
			<td>Micropipettes (1-10mL, 10&#8211;100 mL and 100&#8211;1000 mL)</td>
			<td>VWR International</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ultrasonic cleaning bath</td>
			<td>Branson Ultrasonic</td>
			<td>Model 1510R-DTH</td>
			<td></td>
		</tr>
		<tr>
			<td>Stopwatch</td>
			<td>VWR International</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Eppendorf centrifugation tubes (1.5 mL)</td>
			<td>VWR International</td>
			<td>22364111</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly(propylene) coning tubes (50 mL)</td>
			<td>VWR International</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Home built bright/darkfield microscope</td>
			<td></td>
			<td></td>
			<td>75 W Xenon white light source, Nikon BF/DF 50x ELWD 
			0.55 NA, 8.2 mm WD objective, Nikon D90 digital camera, Acton 2300i spectrometer, Photometrics CoolSnap HQ&#160; charge coupled device (CCD) camera</td>
		</tr>
		<tr>
			<td>He Ne laser (633 nm), 5 mW</td>
			<td>New Port Co.</td>
			<td>R-30990</td>
			<td></td>
		</tr>
		<tr>
			<td>Reflectance standard</td>
			<td>Lab Sphere</td>
			<td>Model SRS-99-010</td>
			<td></td>
		</tr>
		<tr>
			<td>Laser long pass filter 633 nm</td>
			<td>Semrock</td>
			<td>LP02-633RU-25</td>
			<td></td>
		</tr>
	</tbody>
</table>

colloidal synthesis of nanopatch antennas for applications in plasmonics and nanophotonics

私たちは、プラズモニックナノスケールのパッチアンテナを製造するために、コロイド銀ナノキューブの合成と滑らかな金膜との組み合わせでこれらを使用するための方法を提示します。これは、高分子電解質ポリマーの層ごとの堆積、すなわち、ポリ（アリルアミン）塩酸塩（PAH）とポリスチレンスルホン酸（PSS）を使用して、巨視的な面積にわたって十分に制御された厚さの薄膜を製造するための詳細な手順が含まれています。これらの高分子電解質スペーサ層は、銀ナノキューブと金膜の間に誘電体ギャップとして働きます。ナノキューブまたはギャップ厚さの大きさを制御することにより、プラズモン共鳴は、700nmの約500nmから調整することができます。次に、我々はnanopatchアンテナの誘電性ポリマーギャップ領域に有機スルホcyanine5カルボン酸（Cy5の）色素分子を組み込む方法を示しています。最後に、我々は、スペクトル励起エネルギー及びTでプラズモン共鳴を照合することによって、Cy5の色素の著しく増強された蛍光を示します彼は吸収ピークをCY5。ここに提示された方法は、コロイド合成、低コスト、大規模生産のための可能性のあるレイヤーバイレイヤーディップコーティング法を利用し、よく制御された寸法を有するプラズモンnanopatchアンテナの製造を可能にします。これらのnanopatchアンテナは、センシング、超高速光電子デバイスで、高効率の光検出器のための例えば、実用的なアプリケーションのための偉大な約束を保持します。

ここでは、サンプル構造のSEM像、nanopatchアンテナの収集および単nanopatchアンテナからの散乱スペクトルの反射率スペクトルを含むプラズモンnanopatchアンテナの特性の代表的な結果を示します。 nanopatchアンテナのプラズモン共鳴のエネルギー、 すなわちナノキューブのサイズ、誘電体ギャップ領域の厚さに依存し、PE層の数、ならびに誘電体材料。上記の手順では、我々は1-3 nmでの推定厚さのPVP層でコーティングされた75 nmであり、わずかに丸みを帯びた角（10 nmの曲率半径〜）の平均辺長とのAgナノキューブを得ました。 5 PE層と金膜との組み合わせでは、プラズモン共鳴のこの結果は、〜50nmの全幅で半最大（FWHM）で〜650 nmの中心。これにより、Tの吸収および発光波長で良好なスペクトルの重なりを有しています彼は、それぞれ、646および662 nmで中央に配置された分子をCy5で。 図3Aは、ナノキューブの高濃度試料のSEM画像を示します。これらのナノキューブは5 PE層とAu膜の上に堆積させました。このようなSEM画像は、ナノキューブの合成の全体的な品質を検証するために使用されます。ナノキューブの密度が高すぎるしかし、これらのサンプルは、さらに、光学測定のために利用されません。また、高密度のために、いくつかのナノキューブは、プラズモンnanopatchアンテナ構造を形成することが不可欠である表面上に存在しません。 図3Bは、ナノキューブの試料のSEM画像を1/10倍に希釈されたナノキューブの溶液を用いて製造示します。このサンプルはnanopatchアンテナの集合からの白色光の反射率を決定するために測定された測定のために使用され全体的なプラズモン共鳴。 図3Cに示すナノキューブの試料のSEM画像を1/100倍に希釈されたナノキューブの溶液を使用して製造しました。このサンプルは、個々nanopatchアンテナの測定を散乱するために使用されます。希釈されたナノキューブの溶液を使用すると、小さなピンホールを使用して像面に空間的に単離されたことが個人nanopatchアンテナを可能にします。 図4Aは、 図3BのSEM像に示すものに類似した試料から測定白色光の背景と正規化、後に、反射率スペクトルを示す。 図4Bは、に示すサンプルに似た単一nanopatchアンテナからの散乱スペクトルを示しています図3CでのSEM像。 図4Cは、10分の1により調製（nanopatchアンテナ試料の暗視野像を示しますニコンD90デジタルカメラで撮影した5 PE層を金膜上に分散0希釈ナノキューブ溶液）。観察された明るい赤のドットは、個々のnanopatchアンテナからの白色光の散乱によるものです。いくつかのスポットは異なるサイズまたは非立方体形状の大きいナノ粒子とナノキューブの結果である、赤以外の色を有することが観察されています。 図4Dは、制御PE層の同じ番号のスライドガラスからなるサンプル及びCy5の濃度から二つの蛍光スペクトル、（ 図3Cに示すようなサンプルから）単nanopatchアンテナから測定したもの及びその他を示します色素分子。 nanopatchアンテナに結合されたCy5の分子からの蛍光強度は、スライドガラス上よりもはるかに強いです。これは、強化された励起速度ならびに変性放射パターンと色素分子の増大した量子効率が得られる。1<html> 2、励起スポットサイズのナノキューブの下の領域を分割することにより単位面積当たりのバックグラウンド蛍光と正規化のために12を修正した後、我々は、図4（d）に示すデータから、〜12,000の増強因子を得ます。この増強因子は、非放射損失を増加させ、原因代わりにAg膜の金の使用30,000〜12可能性が高いの以前に報告された値と比較して小さくなっています。 <img alt="図1" src="/files/ftp_upload/53876/53876fig1.jpg" /> 銀ナノキューブの合成のための図1.機器のセットアップ。（A）温度制御と撹拌し、ホットプレートの上に加熱浴を示す機器のセットアップの写真。 （B）合成中にナノキューブ溶液を含む丸底フラスコ（RBF）のクローズアップ。セットアップは、適切な換気とヒュームフードの内側に位置しています。TPS：//www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53876/53876fig1large.jpg &quot;ターゲット=&quot; _空白 &quot;&gt;この図の拡大版をご覧になるにはこちらをクリックしてください。 <img alt="図2" src="/files/ftp_upload/53876/53876fig2.jpg" /> 図2.ナノキューブ・ソリューションの写真。2.5時間の合成後の（A）ナノキューブ溶液および（B）小さいチューブに移した後、脱イオン水に再懸濁した。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53876/53876fig2large.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。 。</a> <img alt="図3" src="/files/ftp_upload/53876/53876fig3highres.jpg" width="700" /> 銀ナノキューブの 図3. SEMの特徴付け（A）濃縮ナノキューブサンプルのSEM像、（B）で希釈（1/10）ナノキューブサンプル、および（C）希釈した（1/100）ナノキューブサンプル。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53876/53876fig3highres.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a> <img alt="図4" src="/files/ftp_upload/53876/53876fig4highres.jpg" width="700" /> nanopatchアンテナの 図4 の光学特性評価。nanopatchアンテナの集合から測定（A）正規化された反射スペクトル（非希釈ナノキューブ溶液）。単一nanopatchアンテナから（B）散乱スペクトル（1/100希釈ナノキューブ溶液）。 （C）白色光照明下で撮影されたnanopatchアンテナサンプル（1/100希釈ナノキューブ溶液）の暗視野像。明るい赤い点は、個々のプラズモニックnanopatchアンテナに相当します。埋め込 ​​みのCy5色素分子から（D）蛍光Cy5色素（黒い破線）の同一濃度のガラススライドからのものと比較してnanopatchアンテナ（赤実線）にDED。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53876/53876fig4highres.jpg" target="_blank">この図の拡大版をご覧になるにはこちらをクリックしてください。</a>

Watch this Scientific Journal Video about Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics at JoVE.com

Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics

銀ナノキューブサブ10nmのギャップを有するプラズモンナノスケールのパッチアンテナの製造のコロイド合成のためのプロトコルが提供されます。

プラズモニクスとナノフォトニクスでのアプリケーションのためのNanopatchアンテナのコロイド合成

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic ...

colloidal-synthesis-nanopatch-antennas-for-applications-plasmonics

Nanyang Technological University

Research

JoVE Journal

Engineering

11.0K ビュー.  Duke University. 銀ナノキューブサブ10nmのギャップを有するプラズモンナノスケールのパッチアンテナの製造のコロイド合成のためのプロトコルが提供されます。 

ビデオ: Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics

Hyperpolarized Xenon for NMR and MRI Applications

Nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI) suffer from intrinsic low sensitivity because even strong external magnetic fields of ~10 T generate only a small detectable net-magnetization of the sample at room temperature 1. Hence, most NMR and MRI applications rely on the detection of molecules at relative high concentration (e.g., water for imaging of biological tissue) or require excessive acquisition times. This limits our ability to exploit the very useful molecular specificity of NMR signals for many biochemical and medical applications. However, novel approaches have emerged in the past few years: Manipulation of the detected spin species prior to detection inside the NMR/MRI magnet can dramatically increase the magnetization and therefore allows detection of molecules at much lower concentration 2.
Here, we present a method for polarization of a xenon gas mixture (2-5% Xe, 10% N2, He balance) in a compact setup with a ca. 16000-fold signal enhancement. Modern line-narrowed diode lasers allow efficient polarization 7 and immediate use of gas mixture even if the noble gas is not separated from the other components. The SEOP apparatus is explained and determination of the achieved spin polarization is demonstrated for performance control of the method.
The hyperpolarized gas can be used for void space imaging, including gas flow imaging or diffusion studies at the interfaces with other materials 8,9. Moreover, the Xe NMR signal is extremely sensitive to its molecular environment 6. This enables the option to use it as an NMR/MRI contrast agent when dissolved in aqueous solution with functionalized molecular hosts that temporarily trap the gas 10,11. Direct detection and high-sensitivity indirect detection of such constructs is demonstrated in both spectroscopic and imaging mode.

The production of hyperpolarized xenon by means of spin exchange optical pumping (SEOP) is described. This method yields a ~10000-fold enhancement of the nuclear spin polarization of Xe-129 and has applications in nuclear magnetic resonance spectroscopy and imaging. Examples of gas phase and solution state experiments are given.

NMRやMRIのアプリケーションのための過分極キセノン

Nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI) suffer from intrinsic low sensitivity because even strong external magnetic fields of ~10 ...

工学

Solid-state Graft Copolymer Electrolytes for Lithium Battery Applications

Battery safety has been a very important research area over the past decade. Commercially available lithium ion batteries employ low flash point (&lt;80 &deg;C), flammable, and volatile organic electrolytes. These organic based electrolyte systems are viable at ambient temperatures, but require a cooling system to ensure that temperatures do not exceed 80 &deg;C. These cooling systems tend to increase battery costs and can malfunction which can lead to battery malfunction and explosions, thus endangering human life. Increases in petroleum prices lead to a huge demand for safe, electric hybrid vehicles that are more economically viable to operate as oil prices continue to rise. Existing organic based electrolytes used in lithium ion batteries are not applicable to high temperature automotive applications. A safer alternative to organic electrolytes is solid polymer electrolytes. This work will highlight the synthesis for a graft copolymer electrolyte (GCE) poly(oxyethylene) methacrylate (POEM) to a block with a lower glass transition temperature (Tg) poly(oxyethylene) acrylate (POEA). The conduction mechanism has been discussed and it has been demonstrated the relationship between polymer segmental motion and ionic conductivity indeed has a Vogel-Tammann-Fulcher (VTF) dependence. Batteries containing commercially available LP30 organic (LiPF6 in ethylene carbonate (EC):dimethyl carbonate (DMC) at a 1:1 ratio) and GCE were cycled at ambient temperature. It was found that at ambient temperature, the batteries containing GCE showed a greater overpotential when compared to LP30 electrolyte. However at temperatures greater than 60 &deg;C, the GCE cell exhibited much lower overpotential due to fast polymer electrolyte conductivity and nearly the full theoretical specific capacity of 170 mAh/g was accessed.

Lithium ion batteries employ flammable and volatile organic electrolytes that are suitable for ambient temperature applications. A safer alternative to organic electrolytes are solid polymer batteries. Solid polymer batteries operate safely at high temperatures (&gt;120 &deg;C), thus making them applicable to high temperature applications such as deep oil drilling and hybrid electric vehicles. This paper will discuss (a) the polymer synthesis, (b) the polymer conduction mechanism, and (c) provide temperature cycling for both solid polymer and organic electrolytes.

リチウム電池アプリケーションのためのソリッドステートグラフトコポリマー電解質

Battery safety has been a very important research area over the past decade. Commercially available lithium ion batteries employ low flash point (&lt;80 ...

Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing

This paper discusses fluorescent core microcavity-based sensors that can operate in a microfluidic analysis setup. These structures are based on the formation of a fluorescent quantum-dot (QD) coating on the channel surface of a conventional microcapillary. Silicon QDs are especially attractive for this application, owing in part to their negligible toxicity compared to the II-VI and II-VI compound QDs, which are legislatively controlled substances in many countries. While the ensemble emission spectrum is broad and featureless, an Si-QD film on the channel wall of a capillary features a set of sharp, narrow peaks in the fluorescence spectrum, corresponding to the electromagnetic resonances for light trapped within the film. The peak wavelength of these resonances is sensitive to the external medium, thus permitting the device to function as a refractometric sensor in which the QDs never come into physical contact with the analyte. The experimental methods associated with the fabrication of the fluorescent-core microcapillaries are discussed in detail, as well as the analysis methods. Finally, a comparison is made between these structures and the more widely investigated liquid-core optical ring resonators, in terms of microfluidic sensing capabilities.

Fluorescent-core microcavity sensors employ a high-index quantum-dot coating in the channel of silica microcapillaries. Changes in the refractive index of fluids pumped into the capillary channel cause shifts in the microcavity fluorescence spectrum that can be used to analyze the channel medium.

Refractometricセンシング用蛍光コアマイクロキャビティの合成と操作

This paper discusses  fluorescent core microcavity-based sensors that can operate in a microfluidic  analysis setup. These structures are based on the ...

Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow

3D-PTV is a quantitative flow measurement technique that aims to track the Lagrangian paths of a set of particles in three dimensions using stereoscopic recording of image sequences. The basic components, features, constraints and optimization tips of a 3D-PTV topology consisting of a high-speed camera with a four-view splitter are described and discussed in this article. The technique is applied to the intermediate flow field (5 &#60;x/d &#60;25) of a circular jet at Re &#8776; 7,000. Lagrangian flow features and turbulence quantities in an Eulerian frame are estimated around ten diameters downstream of the jet origin and at various radial distances from the jet core. Lagrangian properties include trajectory, velocity and acceleration of selected particles as well as curvature of the flow path, which are obtained from the Frenet-Serret equation. Estimation of the 3D velocity and turbulence fields around the jet core axis at a cross-plane located at ten diameters downstream of the jet is compared with literature, and the power spectrum of the large-scale streamwise velocity motions is obtained at various radial distances from the jet core.

A three-dimensional particle tracking velocimetry (3D-PTV) system based on a high-speed camera with a four-view splitter is described here. The technique is applied to a jet flow from a circular pipe in the vicinity of ten diameters downstream at Reynolds number Re &#8776; 7,000.

ジェット流の場合：乱流のアプリケーションのための3次元粒子追跡流速

3D-PTV is a quantitative flow measurement technique that aims to track the Lagrangian paths of a set of particles in three dimensions using stereoscopic ...

Creating Sub-50 Nm Nanofluidic Junctions in PDMS Microfluidic Chip via Self-Assembly Process of Colloidal Particles

Polydimethylsiloxane (PDMS) is the prevailing building material to make microfluidic devices due to its ease of molding and bonding as well as its transparency. Due to the softness of the PDMS material, however, it is challenging to use PDMS for building nanochannels. The channels tend to collapse easily during plasma bonding. In this paper, we present an evaporation-driven self-assembly method of silica colloidal nanoparticles to create nanofluidic junctions with sub-50 nm pores between two microchannels. The pore size as well as the surface charge of the nanofluidic junction is tunable simply by changing the colloidal silica bead size and surface functionalization outside of the assembled microfluidic device in a vial before the self-assembly process. Using the self-assembly of nanoparticles with a bead size of 300 nm, 500 nm, and 900 nm, it was possible to fabricate a porous membrane with a pore size of ~45 nm, ~75 nm and ~135 nm, respectively. Under electrical potential, this nanoporous membrane initiated ion concentration polarization (ICP) acting as a cation-selective membrane to concentrate DNA by ~1,700 times within 15 min. This non-lithographic nanofabrication process opens up a new opportunity to build a tunable nanofluidic junction for the study of nanoscale transport processes of ions and molecules inside a PDMS microfluidic chip.

We propose a simple self-assembly technique of silica colloidal nanoparticles to create a nanofluidic junction between two microchannels in polydimethylsiloxane (PDMS). Using this technique, a nanoporous bead membrane with a pore size down to ~45 nm was built inside a microchannel and applied to electrokinetic preconcentration of DNA samples.

コロイド粒子の自己組織化プロセスを介して、PDMSマイクロ流体チップ内のサブ50 Nmのナノ流体ジャンクショ​​ンを作成します

Polydimethylsiloxane (PDMS) is the prevailing building material to make microfluidic devices due to its ease of molding and bonding as well as its ...

Scanning Light Scattering Profiler (SLPS) Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light scattering from intraocular lenses (IOLs) using goniophotometer principles. This protocol describes the SLSP platform and how it employs a 360&#176; rotational photodetector sensor that is scanned around an IOL sample while recording the intensity and location of scattered light as it passes through the IOL medium. The SLSP platform can be used to predict, non-clinically, the propensity for current and novel IOL designs and materials to induce light scatter. Non-clinical evaluation of light scattering properties of IOLs can significantly reduce the number of patient complaints related to unwanted glare, glistening, optical defects, poor image quality, and other phenomena associated with the unintended light scattering. Future studies should be conducted to correlate SLSP data with clinical results to help identify which measured light scatter is most problematic for patients that have undergone cataract surgery subsequent to IOL implantation.

Scanning Light Scattering Profiler SLPS Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

This protocol describes the scanning light scattering profiler (SLSP) that enables the full-angle quantitative evaluation of forward and backward scattering of light from intraocular lenses (IOLs) using goniophotometer principles.

眼内レンズからの前方散乱光および後方散乱光を定量的に評価するための走査型光散乱プロファイラ（SLPS）に基づく方法論

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light ...

Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, interface precipitation, and mini-emulsion. In all methods, well-defined, micrometer-sized spheres are obtained from a self-assembling process in solution. The vapor diffusion method can result in spheres with the highest sphericity and surface smoothness, yet the types of the polymers able to form these spheres are limited. On the other hand, in the mini-emulsion method, microspheres can be made from various types of polymers, even from highly crystalline polymers with coplanar, &#960;-conjugated backbones. The photoluminescent (PL) properties from single isolated microspheres are unusual: the PL is confined inside the spheres, propagates at the circumference of the spheres via the total internal reflection at the polymer/air interface, and self-interferes to show sharp and periodic resonant PL lines. These resonating modes are so-called "whispering gallery modes" (WGMs). This work demonstrates how to measure WGM PL from single isolated spheres using the micro-photoluminescence (&#181;-PL) technique. In this technique, a focused laser beam irradiates a single microsphere, and the luminescence is detected by a spectrometer. A micromanipulation technique is then used to connect the microspheres one by one and to demonstrate the intersphere PL propagation and color conversion from coupled microspheres upon excitation at the perimeter of one sphere and detection of PL from the other microsphere. These techniques, &#181;-PL and micromanipulation, are useful for experiments on micro-optic application using polymer materials.

Protocols for the synthesis of microspheres from polymers, the manipulation of microspheres, and micro-photoluminescence measurements are presented.

光共振器およびレーザ応用のためのポリマーマイクロスフェアの作製

This paper describes three methods of preparing fluorescent microspheres comprising &#960;-conjugated or non-conjugated polymers: vapor diffusion, ...

Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing in combination with new nanofabrication techniques. A plasmon is a quantum of charge density oscillation that lends nanoscale metals such as gold and silver unique optical properties. In particular, gold and silver nanoparticles exhibit localized surface plasmon resonances-collective charge density oscillations on the surface of the nanoparticle-in the visible spectrum. Here, we focus on the fabrication of periodic arrays of anisotropic plasmonic nanostructures. These half-shell (or nanocup) structures can exhibit additional unique light-bending and polarization-dependent optical properties that simple isotropic nanostructures cannot. Researchers are interested in the fabrication of periodic arrays of nanocups for a wide variety of applications such as low-cost optical devices, surface-enhanced Raman scattering, and tamper indication. We present a scalable technique based on colloidal lithography in which it is possible to easily fabricate large periodic arrays of nanocups using spin-coating and self-assembled commercially available polymeric nanospheres. Electron microscopy and optical spectroscopy from the visible to near-infrared (near-IR) was performed to confirm successful nanocup fabrication. We conclude with a demonstration of the transfer of nanocups to a flexible, conformal adhesive film.

We demonstrate the fabrication of periodic gold nanocup arrays using colloidal lithographic techniques and discuss the importance of nanoplasmonic films.

コロイド リソグラフィーを用いた定期的な金 Nanocup アレイの試作

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing ...

Fabrication of Superhydrophobic Metal Surfaces for Anti-Icing Applications

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in industry. The wettability of the produced surface was analyzed by bouncing drop experiments and the topography was analyzed by confocal microscopy. In addition, we show various methodologies to measure its durability and anti-icing properties. Superhydrophobic surfaces hold a special texture that must be preserved to keep their water-repellency. To fabricate durable surfaces, we followed two strategies to incorporate a resistant texture. The first strategy is a direct incorporation of roughness to the metal substrate by acid etching. After this surface texturization, the surface energy was decreased by silanization or fluoropolymer deposition. The second strategy is the growth of a ceria layer (after surface texturization) that should enhance the surface hardness and corrosion resistance. The surface energy was decreased with a stearic acid film.
The durability of the superhydrophobic surfaces was examined by a particle impact test, mechanical wear by lateral abrasion, and UV-ozone resistance. The anti-icing properties were explored by studying the ability to repeal subcooled water, freezing delay, and ice adhesion.

We illustrate several methodologies to produce superhydrophobic metal surfaces and to explore their durability and anti-icing properties.

防氷用超撥水の金属表面の作製

Several ways to produce superhydrophobic metal surfaces are presented in this work. Aluminum was chosen as the metal substrate due to its wide use in ...

A Modular Microfluidic Technology for Systematic Studies of Colloidal Semiconductor Nanocrystals

Colloidal semiconductor nanocrystals, known as quantum dots (QDs), are a rapidly growing class of materials in commercial electronics, such as light emitting diodes (LEDs) and photovoltaics (PVs). Among this material group, inorganic/organic perovskites have demonstrated significant improvement and potential towards high-efficiency, low-cost PV fabrication due to their high charge carrier mobilities and lifetimes. Despite the opportunities for perovskite QDs in large-scale PV and LED applications, the lack of fundamental and comprehensive understanding of their growth pathways has inhibited their adaptation within continuous nanomanufacturing strategies. Traditional flask-based screening approaches are generally expensive, labor-intensive, and imprecise for effectively characterizing the broad parameter space and synthesis variety relevant to colloidal QD reactions. In this work, a fully autonomous microfluidic platform is developed to systematically study the large parameter space associated with the colloidal synthesis of nanocrystals in a continuous flow format. Through the application of a novel translating three-port flow cell and modular reactor extension units, the system may rapidly collect fluorescence and absorption spectra across reactor lengths ranging 3 - 196 cm. The adjustable reactor length not only decouples the residence time from the velocity-dependent mass transfer, it also substantially improves the sampling rates and chemical consumption due to the characterization of 40 unique spectra within a single equilibrated system. Sample rates may reach up to 30,000 unique spectra per day, and the conditions cover 4 orders of magnitude in residence times ranging 100 ms - 17 min. Further applications of this system would substantially improve the rate and precision of the material discovery and screening in future studies. Detailed within this report are the system materials and assembly protocols with a general description of the automated sampling software and offline data processing.

Detailed herein are the operation and assembly protocols of a modular microfluidic screening platform for the systematic characterization of colloidal semiconductor nanocrystal syntheses. Through fully adjustable system arrangements, highly efficient spectra collection may be carried out across 4 orders of magnitude reaction time scales within a mass transfer-controlled sampling space.

コロイド状半導体ナノ結晶の分類学的研究のためのモジュラー マイクロ流体技術

Colloidal semiconductor nanocrystals, known as quantum dots (QDs), are a rapidly growing class of materials in commercial electronics, such as light ...