この作品は、米海軍研究局から提供された資金でサポートされていました。 J·フォンタナはポスドクassociateship国立研究協議会を認めるものです。

1。自己組織化リガンド - ナノ粒子単層次のように自己集合技術の例示的な例として、巨視的、アルカンチオールキャップされた金ナノ球体単層フィルムが製造される。 <ol><li>水中での〜10 13粒子/ ml：（10 12粒子/ ml数密度で市販されている）が15nmの金ナノスフィアを集中。 <ol><li>超遠心フィルター（100 Kの公称分子量限界）に希釈されたナノ球体水懸濁液の15ミリリットルを入れます。 </li><li> 2分間遠心分離や、わずか数ミリリットルまで、4500×gでフィルタ/バイアルは、フィルタ室に残っています。 </li></ol></li><li>脱イオン（DI）水約1mlのナノスフェアを再懸濁し、ナノ粒子濃度が10 13粒子/ mlとなるように。懸濁液を一回DI水中に再懸濁し、数時間安定である。 <ol><li>ヘクタール数密度を確認して、ナノ粒子を確認凝集していないVE。キュベット（1cm経路長）に懸濁物の0.150ミリリットルを配置することによって、元の濃度に1時10倍に濃縮されたナノ粒子懸濁液を希釈し、これに脱イオン水1.35ミリリットルを追加。 </li><li>分析計にキュベットを配置し、サスペンションと、元の懸濁液の吸光スペクトルを測定します。凝集が発生していないことを確認するために半値ピーク位置と全幅を比較してください。両方のサンプルの吸光ピークの大きさは、このように濃縮された試料は、10倍より密であることを確認して、ほぼ同じである必要があります。 </li></ol></li><li>別々のきれいな20ミリリットルホウケイ酸ガラスバイアル中でテトラヒドロフラン（THF）の1ミリリットルを加える。 </li><li> THFにチオールアルカン配位子（1,6 -ヘキサンと5ミリリットルの1 -ドデカンチオール例えば 5ミリリットル）を加え、均一に混合するソリューションを振る。十分なリガンドは、懸濁粒子の少なくとも表面領域全体を覆うように添加されるべきである。 Exceカテゴリーリガンドは、反応の速度および効率を高める。 </li><li>ドラフト内で、THF-リガンドのバイアルに金ナノスフィアを含むバイアルの内容を注ぐ。 </li><li>すぐに蓋のネジと15秒間激しくバイアルを振る。 </li><li>ふたを外し、ドラフト内でダウンバイアルを設定すると、 図1（A）。使用されるリガンドに依存して、金ナノ粒子薄膜のドメインは、速やかに空気-液体界面、 図1（c）に形成する。次に、フィルムを、図1（d）に示すように、バイアルの側面を変換するために開始されます。ほぼすべてのナノ粒子は、チオール配位子でキャップされた懸濁液から取り出し、1時間、 図1（e）の内のバイアルの側面に搬送される。 </li></ol> 2。取り外し可能な基板上に単層の転送<ol><li>取り外し可能なガラスやシリコンウエハ基板上に薄膜を転送するには、次のように使用してX 25.4ミリメートル12.5ミリメートルの領域に基板をカットスクライビングペン/ホイール。 <ol><li>ガラス基板：清浄なイソプロピルアルコールでリンスし、アセトンリンスし、最後にDI水洗浄を用いて。セクション2.2に進んで、基板を乾燥させる。 </li><li>シリコンウエハ下地：ドラフト中ピラニア溶液を調製し、（3部を1部の30％過酸化水素、CAUTIONに濃硫酸：腐食性の酸化剤）。 20ミリリットルのホウケイ酸ガラスバイアルに15mlの硫酸を置き。これは徐々に 30％過酸化水素の5ミリリットルを追加する。バイアルにキャップをしないでください 。十分に注意してください。混合物は、非常に発熱性である。より多くの安全情報19のためのリファレンスを参照してください。 </li><li>慎重に、30分間ピラニア溶液にシリコンウエハ基板を沈める削除、DI水と窒素で乾燥してすすいでください。 </li><li>オプションの手順として、ナノ粒子配位子交換と自己組織化のために使用されるバイアルは、ガラス基板やSi上に全てのナノ粒子を強制的に塩水化することができますliconガラスバイアルの壁の代わりにウェハそうでないセクション2.2に進んでください。 </li><li>ピラニア溶液（ 注意：酸化剤、腐食性）をガラスバイアルを埋める、2.1.2項を参照してください。 </li><li>バイアルを30分間浸すことができます。 30分後、DI水でバイアルをすすぎます。 </li><li>アセトン、キャップ内のヘキサメチルジシラザンの1％v / Vでバイアルを埋める。 </li><li> DI水と窒素で乾燥で洗い流し、その後、密封したバイアルを24時間浸すことができます。 </li></ol></li><li> （セクション1.6）しながらする前にバイアルに基板を挿入します。蓋と揺れのネジ。 </li><li>ふたを取り外して、ピンセットを用いて振とうした後、バイアル壁に垂直に近い基板を配置します。 </li><li>基材上にコートを反応混合物にピペットを使用してください。全ての有機溶媒を蒸発させたか、またはすべてのナノ粒子が懸濁液から除去されたときに反応は停止する。 </li></ol> 3。単層の分析<ol><li>推定フィルムの透過と反射特性を観察することによって、迅速に単層でナノスフィアの効率をパッキング。白色光源と背後からガラス基板上に単分子層を照らす。白色光源と、均一な着色膜を透過及び反射は 、 図2で観察された金のような反射における高密度のナノ粒子単層フィルムについて観察されるべきである。 </li><li>単層、 図4から巨視的吸収スペクトルを定量化する（1.2.2項を参照）分光計を使用しています。きれいなガラススライドで吸収スペクトルを正規化します。分光計のビーム経路内に、ガラス基板上に、単層フィルムをマウントし、吸光度スペクトルを収集する。 注意：吸光度のピークが使わリガンドによって大きく赤方偏移し、数百ナノメートルにする必要があります。吸光度ピークの品質係数は、希釈懸濁液値に匹敵するが、わずかにBべきroadened（ 図4）。吸収ピークが明確に定義された非常に広いかでなければ、単層フィルムは、おそらく低品質のものであり、さらなる特徴付けのためのセクション3.3に進んでください。 </li><li> 図3に示すように（セクション2.1.2を参照）、シリコンウエハ基板上に転写された単層の走査電子顕微鏡（SEM）を用いてナノスフェアのナノスケールの組織化を調べる。膜をガラス基板上にある場合、フィルムの一方の隅に導電性テープを接続する帯電を防止し、画像化を可能にするためにSEM台に接地してください。 </li></ol>有機性ナノ粒子のための4。効率的な位相転送技術<ol><li> 、チオール配位子を有するナノ粒子を官能化する効率的な手段のような技術を使用して、反応が完了した後、バイアルの底部からの残りの溶液をデカントし、セクション1.7、そして窒素下でバイアル中に材料を乾燥させる。 </li><li>有機溶剤を追加します（ 例：クロロホルム、ほぼ100％の粒子相間移動および回復を有するナノ粒子を再懸濁するためにトルエン）。 </li><li>ナノ粒子は、有機溶媒中に再懸濁すると集計されていないことを確認するためにセクション1.2.1を繰り返します。吸光度ピークは、元の懸濁液に対して基板である場合、 図4に 、ナノ粒子を再分散を助けるために15分間、試料を超音波処理する。 </li></ol>

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このプロトコルは、相転移、相分離および表面張力勾配を用いて巨視的なナノ粒子 - リガンド単層フィルムを作成するために単一の「ワンポット」自己組織化技術が記載されている。この技術の利点は、単一の低コストのプロセスに3自己組織化プロセスを組み合わせることである。迅速かつ効率的に相、ナノ粒子を転送する空気 - 流体界面での単層に粒子を組み立て、テンプレート·フリー?...

巨視的ナノ粒子膜の自己組織化は、要素5のジオメトリや組成から求め、そのユニークな特性のために大きな注目を集めていると、光学的、電子的および化学的なアプリケーション6月14日の広い範囲のにつながる可能性があります。自己組織化するような膜へのリガンドでキャップされた金属ナノ粒子は、高密度、単層にパックされている必要があります。しかしながら、いくつかのアセンブリの問題は、そのような材料の開発を進めるために対処する必要がある。 まず、界面活性剤は、金属ナノ粒子は、一般的に希薄な懸濁液15中のウェット化学法により合成される安定した。凝集を防止し、薄膜中のナノ粒子の粒子間間隔を制御するために、ナノ粒子は、リガンドシェルでキャップされる必要がある。ナノ粒子は、リガンドで官能化された後、ナノ粒子は、典型的には、比較的希薄な懸濁液に残る。技術はその後、NEですeded巨視的に、高密度、単層フィルム16,17内にナノ粒子を自己組織化する。 チェンら 18相は、水-テトラヒドロフラン懸濁液中チオール化ポリスチレンを用いた金ナノロッドを移す。次いで、クロロホルム中に再懸濁し、液滴が空気 - 水界面に配置された単層膜を形成し、徐々に蒸発させたナノロッド。 Bigioni ら 17は、過剰なリガンドと迅速な溶媒蒸発を使用ドデカン頂いた金ナノスフィアの巨視的な単層を作成しましたが、ナノスフィアは、自己組織化の前に移さ相である必要がありました。 単層フィルムが形成されると、それらは、典型的には、基板上に搬送する必要がある。 Mayya ら 3水-トルエン界面でのナノ球体に閉じ込め、表面張力の勾配を使用して、テンプレート·フリー基板上にそれらを移す。同様に、ジョンソン<emは&gt;ら4は、過剰の配位子中の銀ナノスフィアを懸濁し、2つの不混和流体から表面張力の勾配を使用して、バイアルの壁をナノ粒子を翻訳した。組立技術は、これらの問題のそれぞれに対処するために存在するが、より効率的な技術の必要性は、大規模ナノ粒子膜の生産の発展を支援するために必要とされる。 ここでは、 図1に示される単一の「ワンポット」技法にして上記で説明した3つの自己集合の問題を組み合わせて、簡単かつ堅牢な技術を実証する。水混和性有機溶媒（ 例えば 、テトラヒドロフラン、dimeythlスルホキシド）に使用される最初に、迅速かつ効率的にナノ粒子（ 例えば金ナノスフェア、ナノロッドなど）の上にチオール-リガンド（ 例えば 、チオールアルカンチオール-エン、チオール-フェノール）を官能。次いで、混合物を巨視的高密度、monolaにナノ粒子の自己集合を駆動する相分離を用いて空気流体界面におけるヤーフィルム。最後に、ナノ粒子の単層フィルムは、水/有機溶媒混合物を、 図2および図3から表面張力の勾配を使用してテンプレートを含まない基材上に形成する。

<table border="0" cellpadding="0" cellspacing="0" width="628">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">1-6 hexanedithiol</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">H12005-5G</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">1-dodecanethiol</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">471364-100ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">20 ml liquid scintillation vials</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">Z253081-1PAK</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;width:224px;">acetone</td>
			<td style="width:97px;">Sigma</td>
			<td>650501-1L</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:224px;">amicon ultra-15 centrifugal filter&#160;</td>
			<td style="width:97px;">Millipore</td>
			<td style="width:140px;">100K</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">centrifuge</td>
			<td style="width:97px;">Sorvall&#160;</td>
			<td style="width:140px;">RC5B</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">centrifuge&#160;</td>
			<td style="width:97px;">Eppendorf</td>
			<td style="width:140px;">5810R</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">deionized water&#160;</td>
			<td style="width:97px;">in-house&#39;</td>
			<td style="width:140px;">N/A</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:25px;width:224px;">glass slides</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">CLS294875X25-72EA</td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:224px;">15 nm gold nanospheres</td>
			<td style="width:97px;">Ted Pella, Inc</td>
			<td style="width:140px;">15703-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">hexamethyldisilazane</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">52619-50ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">hydrogen peroxide (30%)</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">216763-100ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">scanning electron microscope</td>
			<td style="width:97px;">Carl Zeiss</td>
			<td style="width:140px;">Model 55</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">polished silicon wafer</td>
			<td style="width:97px;">Sun Edison</td>
			<td style="width:140px;">N/A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">spectrometer</td>
			<td style="width:97px;">OceanOptics</td>
			<td style="width:140px;">USB4000-VIS-NIR</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">sulfuric acid</td>
			<td style="width:97px;">Fisher</td>
			<td style="width:140px;">A300-212</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:224px;">tetrahydrofuran</td>
			<td style="width:97px;">Sigma</td>
			<td style="width:140px;">401757-100ML</td>
			<td></td>
		</tr>
	</tbody>
</table>

a technique to functionalize and self-assemble macroscopic nanoparticle-ligand monolayer films onto template-free substrates

このプロトコルは、リガンドコーティングされたナノ粒子1個、2個からなる巨視的な単層フィルムを作成するための自己組織化技術が記載されている。単純堅牢でスケーラブルな技術は、効率的に、金ナノ粒子表面上へのチオール基の迅速な移植を可能に混和性の水/有機溶媒混合物中のチオール配位子を有する金属ナノ粒子を官能化する。ナノ粒子上の疎水性リガンドはその後すぐに相は水系懸濁液からナノ粒子を分離し、空気流体界面にそれらを閉じ込める。これは、空気流体界面で単層ドメインを形成する配位子でキャップされたナノ粒子を駆動する。それがテンプレート·フリー·基板上に界面からのナノ粒子の輸送を可能にするような水混和性有機溶媒の使用が重要である。流れが表面張力勾配3,4によって媒介される巨視的、高密度単層nanopを作成している記事 - リガンドフィルム。この自己組織化技術は、異なる組成の粒子の使用は、サイズ、及び形状を含むように一般化することができ、広範にアプリケーション用の低コスト、巨視的、高密度の単層ナノ粒子薄膜を製造するために効率的な組立方法につながる可能性が。

図1（a）は、混合直後の金ナノスフィア、アルカンチオール配位子、テトラヒドロフラン、ガラスバイアル中の水の懸濁液を示す。 3つの主要な自己組織化段階の概略、相転移、相分離、および媒介表面張力勾配が膜輸送は、バイアルの側面近傍の空気-流体界面での拡大図として図1の（b）に示されている。 リガンド上のチオール基は、急速に?...

Watch this Scientific Journal Video about A Technique to Functionalize and Self-assemble Macroscopic Nanoparticle-ligand Monolayer Films onto Template-free Substrates at JoVE.com

A Technique to Functionalize and Self-assemble Macroscopic Nanoparticle-ligand Monolayer Films onto Template-free Substrates

テンプレート·フリー基板上に肉眼で見える粒子 - リガンド単層フィルムを官能して自己組織化するために、シンプルな堅牢でスケーラブルな技術が、このプロトコルで説明されています。

テンプレート·フリー基板上に巨視的粒子 - リガンド単層フィルムを官能して自己組織化するための技術

This protocol describes a self-assembly technique to create macroscopic monolayer films composed of ligand-coated nanoparticles1,2. The simple, robust and ...

a-technique-to-functionalize-self-assemble-macroscopic-nanoparticle

Research

JoVE Journal

Chemistry

10.8K ビュー.  Naval Research Laboratory. テンプレート·フリー基板上に肉眼で見える粒子 - リガンド単層フィルムを官能して自己組織化するために、シンプルな堅牢でスケーラブルな技術が、このプロトコルで説明されています。 

ビデオ: A Technique to Functionalize and Self-assemble Macroscopic Nanoparticle-ligand Monolayer Films onto Template-free Substrates

Covalent Binding of BMP-2 on Surfaces Using a Self-assembled Monolayer Approach

Bone morphogenetic protein 2 (BMP-2) is a growth factor embedded in the extracellular matrix of bone tissue. BMP-2 acts as trigger of mesenchymal cell differentiation into osteoblasts, thus stimulating healing and de novo bone formation. The clinical use of recombinant human BMP-2 (rhBMP-2) in conjunction with scaffolds has raised recent controversies, based on the mode of presentation and the amount to be delivered. The protocol presented here provides a simple and efficient way to deliver BMP-2 for in vitro studies on cells. We describe how to form a self-assembled monolayer consisting of a heterobifunctional linker, and show the subsequent binding step to obtain covalent immobilization of rhBMP-2. With this approach it is possible to achieve a sustained presentation of BMP-2 while maintaining the biological activity of the protein. In fact, the surface immobilization of BMP-2 allows targeted investigations by preventing unspecific adsorption, while reducing the amount of growth factor and, most notably, hindering uncontrolled release from the surface. Both short- and long-term signaling events triggered by BMP-2 are taking place when cells are exposed to surfaces presenting covalently immobilized rhBMP-2, making this approach suitable for in vitro studies on cell responses to BMP-2 stimulation.

We describe a method for accomplishing efficient immobilization of BMP-2 on surfaces. Our approach is based on the formation of a self-assembled monolayer to achieve the covalent binding of BMP-2 via its free amine residues. This method is a useful tool to study signaling at the cell membrane.

共有結合は、自己組織化単分子膜の手法を用いて表面上のBMP-2の結合

Bone morphogenetic protein 2 (BMP-2) is a growth factor embedded in the extracellular matrix of bone tissue. BMP-2 acts as trigger of mesenchymal cell ...

化学

Towards Biomimicking Wood: Fabricated Free-standing Films of Nanocellulose, Lignin, and a Synthetic Polycation

Woody materials are comprised of plant cell walls that contain a layered secondary cell wall composed of structural polymers of polysaccharides and lignin. Layer-by-layer (LbL) assembly process which relies on the assembly of oppositely charged molecules from aqueous solutions was used to build a freestanding composite film of isolated wood polymers of lignin and oxidized nanofibril cellulose (NFC). To facilitate the assembly of these negatively charged polymers, a positively charged polyelectrolyte, poly(diallyldimethylammomium chloride) (PDDA), was used as a linking layer to create this simplified model cell wall. The layered adsorption process was studied quantitatively using quartz crystal microbalance with dissipation monitoring (QCM-D) and ellipsometry. The results showed that layer mass/thickness per adsorbed layer increased as a function of total number of layers. The surface coverage of the adsorbed layers was studied with atomic force microscopy (AFM). Complete coverage of the surface with lignin in all the deposition cycles was found for the system, however, surface coverage by NFC increased with the number of layers. The adsorption process was carried out for 250 cycles (500 bilayers) on a cellulose acetate (CA) substrate. Transparent free-standing LBL assembled nanocomposite films were obtained when the CA substrate was later dissolved in acetone. Scanning electron microscopy (SEM) of the fractured cross-sections showed a lamellar structure, and the thickness per adsorption cycle (PDDA-Lignin-PDDA-NC) was estimated to be 17 nm for two different lignin types used in the study. The data indicates a film with highly controlled architecture where nanocellulose and lignin are spatially deposited on the nanoscale (a polymer-polymer nanocomposites), similar to what is observed in the native cell wall.

The objective of this research was to form synthetic plant cell wall tissue using layer-by-layer assembly of nanocellulose fibrils and isolated lignin assembled from dilute aqueous suspensions.&#160; Surface measurement techniques of quartz crystal microbalance and atomic force microscopy were used to monitor the formation of the polymer-polymer nanocomposite material.

Nanocellulose、リグニンから製造自立フィルム、合成ポリカチオン：Biomimickingウッドに向けて

Woody materials are comprised of plant cell walls that contain a layered secondary cell wall composed of structural polymers of polysaccharides and ...

Atomically Defined Templates for Epitaxial Growth of Complex Oxide Thin Films

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain such surfaces are described. The first approach is the preparation of single terminated perovskite SrTiO3 (001) and DyScO3 (110) substrates. Wet etching was used to selectively remove one of the two possible surface terminations, while an annealing step was used to increase the smoothness of the surface. The resulting single terminated surfaces allow for the heteroepitaxial growth of perovskite oxide thin films with high crystalline quality and well-defined interfaces between substrate and film. In the second approach, seed layers for epitaxial film growth on arbitrary substrates were created by Langmuir-Blodgett (LB) deposition of nanosheets. As model system Ca2Nb3O10- nanosheets were used, prepared by delamination of their layered parent compound HCa2Nb3O10. A key advantage of creating seed layers with nanosheets is that relatively expensive and size-limited single crystalline substrates can be replaced by virtually any substrate material.

Various procedures are outlined to prepare atomically defined templates for epitaxial growth of complex oxide thin films. Chemical treatments of single crystalline SrTiO3 (001) and DyScO3 (110) substrates were performed to obtain atomically smooth, single terminated surfaces. Ca2 Nb3 O10- nanosheets were used to create atomically defined templates on arbitrary substrates.

複合酸化物薄膜のエピタキシャル成長のために原子的に定義されたテンプレート

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain ...

Fabrication of Large-area Free-standing Ultrathin Polymer Films

This procedure describes a method for the fabrication of large-area and ultrathin free-standing polymer films. Typically, ultrathin films are prepared using either sacrificial layers, which may damage the film or affect its mechanical properties, or they are made on freshly cleaved mica, a substrate that is difficult to scale. Further, the size of ultrathin film is typically limited to a few square millimeters. In this method, we modify a surface with a polyelectrolyte that alters the strength of adhesion between polymer and deposition substrate. The polyelectrolyte can be shown to remain on the wafer using spectroscopy, and a treated wafer can be used to produce multiple films, indicating that at best minimal amounts of the polyelectrolyte are added to the film. The process has thus far been shown to be limited in scalability only by the size of the coating equipment, and is expected to be readily scalable to industrial processes. In this study, the protocol for making the solutions, preparing the deposition surface, and producing the films is described.

We describe a method for the fabrication of large-area (up to 13 cm diameter) and ultrathin (as thin as 8 nm) polymer films. Instead of using a sacrificial interlayer to delaminate the film from its substrate, we use a self-limiting surface treatment suitable for arbitrarily large areas.

大面積自立超薄ポリマーフィルムの作製

This procedure describes a method for the fabrication of large-area and ultrathin free-standing polymer films.  Typically, ultrathin films are prepared ...

Preparation of Mica and Silicon Substrates for DNA Origami Analysis and Experimentation

The designed nature and controlled, one-pot synthesis of DNA origami provides exciting opportunities in many fields, particularly nanoelectronics. Many of these applications require interaction with and adhesion of DNA nanostructures to a substrate. Due to its atomically flat and easily cleaned nature, mica has been the substrate of choice for DNA origami experiments. However, the practical applications of mica are relatively limited compared to those of semiconductor substrates. For this reason, a straightforward, stable, and repeatable process for DNA origami adhesion on derivatized silicon oxide is presented here. To promote the adhesion of DNA nanostructures to silicon oxide surface, a self-assembled monolayer of 3-aminopropyltriethoxysilane (APTES) is deposited from an aqueous solution that is compatible with many photoresists. The substrate must be cleaned of all organic and metal contaminants using Radio Corporation of America (RCA) cleaning processes and the native oxide layer must be etched to ensure a flat, functionalizable surface. Cleanrooms are equipped with facilities for silicon cleaning, however many components of DNA origami buffers and solutions are often not allowed in them due to contamination concerns. This manuscript describes the set-up and protocol for in-lab, small-scale silicon cleaning for researchers who do not have access to a cleanroom or would like to incorporate processes that could cause contamination of a cleanroom CMOS clean bench. Additionally, variables for regulating coverage are discussed and how to recognize and avoid common sample preparation problems is described.

Reproducible cleaning processes for substrates used in DNA origami research are described, including bench-top RCA cleaning and derivatization of silicon oxide. Protocols for surface preparation, DNA origami deposition, drying parameters, and simple experimental set-ups are illustrated.

DNA折り紙解析と実験のためのマイカとシリコン基板の作製

The designed nature and controlled, one-pot synthesis of DNA origami provides exciting opportunities in many fields, particularly nanoelectronics. Many of ...

Cooling Rate Dependent Ellipsometry Measurements to Determine the Dynamics of Thin Glassy Films

This report aims to fully describe the experimental technique of using ellipsometry for cooling rate dependent Tg (CR-Tg) experiments. These measurements are simple high-throughput characterization experiments, which can determine the glass transition temperature (Tg), average dynamics, fragility and the expansion coefficient of the super-cooled liquid and glassy states for a variety of glassy materials. This technique allows for these parameters to be measured in a single experiment, while other methods must combine a variety of different techniques to investigate all of these properties. Measurements of dynamics close to Tg are particularly challenging. The advantage of cooling rate dependent Tg measurements over other methods which directly probe bulk and surface relaxation dynamics is that they are relatively quick and simple experiments, which do not utilize fluorophores or other complicated experimental techniques. Furthermore, this technique probes the average dynamics of technologically relevant thin films in temperature and relaxation time (&#964;&#945;) regimes relevant to the glass transition (&#964;&#945; &#62; 100 sec). The limitation to using ellipsometry for cooling rate dependent Tg experiments is that it cannot probe relaxation times relevant to measurements of viscosity (&#964;&#945; &#60;&#60; 1 sec). Other cooling rate dependent Tg measurement techniques, however, can extend the CR-Tg method to faster relaxation times. Furthermore, this technique can be used for any glassy system so long as the integrity of the film remains throughout the experiment.

Here, we present a protocol for cooling rate dependent ellipsometry experiments, which can determine the glass transition temperature (Tg), average dynamics, fragility and the expansion coefficient of the super-cooled liquid and glass for a variety of glassy materials.

薄いガラス質膜のダイナミクスを決定するレート依存エリプソメトリー測定を冷却

This report aims to fully describe the experimental technique of using ellipsometry for cooling rate dependent Tg (CR-Tg) experiments. These measurements ...

Deacetylation Assays to Unravel the Interplay between Sirtuins (SIRT2) and Specific Protein-substrates

Acetylation has emerged as an important post-translational modification (PTM) regulating a plethora of cellular processes and functions. This is further supported by recent findings in high-resolution mass spectrometry based proteomics showing that many new proteins and sites within these proteins can be acetylated. However the identity of the enzymes regulating these proteins and sites is often unknown. Among these enzymes, sirtuins, which belong to the class III histone lysine deacetylases, have attracted great interest as enzymes regulating the acetylome under different physiological or pathophysiological conditions. Here we describe methods to link SIRT2, the cytoplasmic sirtuin, with its substrates including both in vitro and in vivo deacetylation assays. These assays can be applied in studies focused on other members of the sirtuin family to unravel the specific role of sirtuins and are necessary in order to establish the regulatory interplay of specific deacetylases with their substrates as a first step to better understand the role of protein acetylation. Furthermore, such assays can be used to distinguish functional acetylation sites on a protein from what may be non-regulatory acetylated lysines, as well as to examine the interplay between a deacetylase and its substrate in a physiological context.

Deacetylation Assays to Unravel the Interplay between Sirtuins SIRT2 and Specific Protein-substrates

This protocol describes the required steps to execute in vitro and in vivo deacetylation assays in order to establish the role of proteins as specific deacetylation substrates for sirtuins and further study the role of reversible - lysine acetylation as a post-translational modification.

脱アセチル化アッセイは、サーチュインの間にInterplay（SIRT2）と特異的なタンパク質 - 基質を解明します

Acetylation has emerged as an important post-translational modification (PTM) regulating a plethora of cellular processes and functions. This is further ...

Capillary Electrophoresis to Monitor Peptide Grafting onto Chitosan Films in Real Time

Free-solution capillary electrophoresis (CE) separates analytes, generally charged compounds in solution through the application of an electric field. Compared to other analytical separation techniques, such as chromatography, CE is cheap, robust and effectively requires no sample preparation (for a number of complex natural matrices or polymeric samples). CE is fast and can be used to follow the evolution of mixtures in real time (e.g., chemical reaction kinetics), as the signals observed for the separated compounds are directly proportional to their quantity in solution.
Here, the efficiency of CE is demonstrated for monitoring the covalent grafting of peptides onto chitosan films for subsequent biomedical applications. Chitosan&#39;s antimicrobial and biocompatible properties make it an attractive material for biomedical applications such as cell growth substrates. Covalently grafting the peptide RGDS (arginine - glycine - aspartic acid - serine) onto the surface of chitosan films aims at improving cell attachment. Historically, chromatography and amino acid analysis have been used to provide a direct measurement of the amount of grafted peptide. However, the fast separation and absence of sample preparation provided by CE enables equally accurate yet real-time monitoring of the peptide grafting process. CE is able to separate and quantify the different components of the reaction mixture: the (non-grafted) peptide and the chemical coupling agents. In this way the use of CE results in improved films for downstream applications.
The chitosan films were characterized through solid-state NMR (nuclear magnetic resonance) spectroscopy. This technique is more time-consuming and cannot be applied in real time, but yields a direct measurement of the peptide and thus validates the CE technique.

Free solution capillary electrophoresis is a fast, cheap and robust analytical method that enables the quantitative monitoring of chemical reactions in real time. Its utility for rapid, convenient and precise analysis is demonstrated here through analysis of covalent peptide grafting onto chitosan films for improved cell adhesion.

リアルタイムでのキトサンフィルム上にペプチドグラフトを監視するためのキャピラリー電気泳動

Free-solution capillary electrophoresis (CE) separates analytes, generally charged compounds in solution through the application of an electric field. ...

Reactive Vapor Deposition of Conjugated Polymer Films on Arbitrary Substrates

We demonstrate a method of conformally coating conjugated polymers on arbitrary substrates using a custom-designed, low-pressure reaction chamber. Conductive polymers, poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-propylenedioxythiophene) (PProDOT), and a semiconducting polymer, poly(thieno[3,2-b]thiophene) (PTT), were deposited on unconventional highly-disordered and textured substrates with high surface areas, such as paper, towels and fabrics. This reported deposition chamber is an improvement of previous vapor reactors because our system can accommodate both volatile and nonvolatile monomers, such as 3,4-propylenedioxythiophene and thieno[3,2-b]thiophene. Utilization of both solid and liquid oxidants are also demonstrated. One limitation of this method is that it lacks sophisticated in situ thickness monitors. Polymer coatings made by the commonly used solution-based coating methods, such as spin-coating and surface grafting, are often not uniform or susceptible to mechanical degradation. This reported vapor phase deposition method overcomes those drawbacks and is a strong alternative to common solution-based coating methods. Notably, polymer films coated by the reported method are uniform and conformal on rough surfaces, even at a micrometer scale. This feature allows for future application of vapor deposited polymers in electronics devices on flexible and highly textured substrates.

This paper presents a protocol for reactive vapor deposition of poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), and poly(thieno[3,2-b]thiophene) films on glass slides and rough substrates, such as textiles and paper.

任意の基板上への共役ポリマー薄膜の反応性蒸着

We demonstrate a method of conformally coating conjugated polymers on arbitrary substrates using a custom-designed, low-pressure reaction chamber. ...

Solution-Processed "Silver-Bismuth-Iodine" Ternary Thin Films for Lead-Free Photovoltaic Absorbers

Bismuth-based hybrid perovskites are regarded as promising photo-active semiconductors for environment-friendly and air-stable solar cell applications. However, poor surface morphologies and relatively high bandgap energies have limited their potential. Silver-bismuth-iodine (Ag-Bi-I) is a promising semiconductor for optoelectronic devices. Therefore, we demonstrate the fabrication of Ag-Bi-I ternary thin films using material solution processing. The resulting thin films exhibit controlled surface morphologies and optical bandgaps according to their thermal annealing temperatures. In addition, it has been reported that Ag-Bi-I ternary systems crystallize to AgBi2I7, Ag2BiI5, etc. according to the ratio of the precursor chemicals. The solution-processed AgBi2I7 thin films exhibit a cubic-phase crystal structure, dense, pinhole-free surface morphologies with grains ranging in size from 200 to 800 nm, and an indirect bandgap of 1.87 eV. The resultant AgBi2I7 thin films show good air stability and energy band diagrams, as well as surface morphologies and optical bandgaps suitable for lead-free and air-stable single-junction solar cells. Very recently, a solar cell with 4.3% power conversion efficiency was obtained by optimizing the Ag-Bi-I crystal compositions and solar cell device architectures.

Solution-Processed &quot;Silver-Bismuth-Iodine&quot; Ternary Thin Films for Lead-Free Photovoltaic Absorbers

Herein, we present detailed protocols for solution-processed silver-bismuth-iodine (Ag-Bi-I) ternary semiconductor thin films fabricated on TiO2-coated transparent electrodes and their potential application as air-stable and lead-free optoelectronic devices.

ソリューション処理「銀ビスマス ヨード」三項薄膜鉛フリー太陽光吸収体の

Bismuth-based hybrid perovskites are regarded as promising photo-active semiconductors for environment-friendly and air-stable solar cell applications. ...