This material is based upon work supported by the U.S. Department of Homeland Security under Grant Award Number 2010-ST-061-FD0001 through a grant awarded by the National Center for Food Protection and Defense at the University of Minnesota. Disclaimer: The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Department of Homeland Security or the National Center for Food Protection and Defense.

1.銀ナノ粒子の合成15 <ol><li> 5秒間100ミリリットルの超純水（18.2ΩU）とボルテックスで18 mgの硝酸銀を溶解させます。 </li><li> 5秒間1ミリリットルの水とボルテックスで27 mgのクエン酸ナトリウム二水和物を溶解させます。 </li><li>撹拌棒を含む三角フラスコに準備された硝酸銀溶液のすべてを転送し、磁気ホットプレート上にフラスコを置きます。 〜350℃で700rpmでの撹拌速度で激しく撹拌しながらフラスコを加熱（プレート上で温度を設定）。 </li><li>沸騰した場合、直ちに三角フラスコに準備されたクエン酸ナトリウム溶液のすべてを追加し、解決策は、Ag NPの形成を示す緑がかった茶色を、なるまでさらに25分間沸騰するソリューションを残します。 </li><li>ホットプレートからフラスコを外し、一定の色やトランで、別の磁性板の上に置いた（加熱しないでください）​​、攪拌O / NがRTで同じ撹拌速度で混合物が安定状態に達するまでsparency。必要に応じて用意したAg NPの吸光度を決定するために、紫外可視分光光度計を使用してください。 </li><li> 100mlに超純水を用いて最終混合物を希釈します。 </li><li>必要に応じて、製造業者のプロトコルに従ってのAg NPのサイズを測定するゼータサイザーを使用してください。 </li><li>密閉容器に銀コロイドを移し、アルミホイルで光から保護します。必要に応じてコロイドを2ヶ月間4-7℃の冷蔵庫に保存することができます。 </li></ol> SERSアクティブフィルタ膜の2製作<ol><li> 50mMのNaCl溶液を作るために水100mlに2.92はグラムの塩化ナトリウム（食塩）を溶解します。 </li><li>用意したAg NPの1ミリリットル中に5 mMのNaCl溶液の1ミリリットルを追加し、20 rpmで10分間章動ミキサーで混ぜます。このステップでは、Agナノクラスターの中に銀のNPを集約することです。 </li><li>注射器に取り付けることができるフィルタホルダにフィルター膜（PVDF、0.1μmの孔径）を置きます。より小さい孔サイズ膜FOました銀ナノクラスターを捕捉し、一貫性のある信号を生成する際に、より大きな細孔サイズの膜（ すなわち、0.22μmの）よりウントより効果的。 </li><li>濾過のための注射器にロード用意したAgナノクラスターの2ミリリットルを。シリンジにフィルターホルダーを取り付け、手動で1滴/秒の流量で膜を通してのAgナノクラスターのボリューム全体を渡します。膜トラップのAgナノクラスターは、SERS活性フィルター膜を形成します。 </li><li>フィルターホルダーからフィルター膜を外します。膜への損傷を受けないためにピンセットを使用して、外リムに膜を保持している場合には、特別な注意が必要とされています。スライドガラス上に約3分と場所膜用の空気乾燥。 </li><li> SERS基板のラマン検出<ol><li> 5mWと、10倍の顕微鏡対物レンズをセット2の1秒、露出数の露光時間のレーザパワーと波長780nmのレーザにラマン測定器を設定します。ソフトウェア上の目的は、あまりにもそれに応じて設定されていることを確認します。&lt;/李&gt; <li>ラマン計測器のプラットフォーム上に上に膜を有するガラススライドを配置し、膜の表面に集中する顕微鏡を使用しています。 </li><li>ランダム膜表面8から10のスポットを選択し、機器が順番に自動的にそれらを収集します。分析のための製造元のソフトウェアでのスペクトルデータを開きます。 </li></ol></li></ol>化学汚染物質を検出するために、SERSアクティブフィルタシステムの3.アプリケーション<ol><li> 10 ppbでのフェルバム溶液を調製します。 注意：フェルバムは非常に揮発性です。固体を計量する際の注意事項（人工呼吸器やゴーグル）を使用します。 <ol><li> 2ミリグラムフェルバム粉末を秤量し、ストック溶液（100 ppm）を行う20 50mlの％アセトニトリル（10mLのアセトニトリルおよび10mlの水）の中に溶解します。 30秒間フラスコを渦。 </li><li>試験管に100ppmのフェルバム溶液1mlを取り、10ppmの溶液を作る9 50mlの％アセトニトリルを加えます。 5秒間チューブをボルテックス。 </li><li>の1ミリリットルを取り10 ppmの試験管内の溶液と9ミリリットルの50％アセトニトリルを追加するには、1 ppmの溶液を作製します。 5秒間チューブをボルテックス。 </li><li>試験管内では1ppm溶液1mlを取り、100ppbの溶液を作製するために9ミリリットルの50％アセトニトリルを追加します。 5秒間チューブをボルテックス。 </li><li>試験管内で100ppbの溶液1mlを取り、10 ppbの溶液を作製するために9ミリリットルの50％アセトニトリルを追加します。 5秒間チューブをボルテックス。 </li></ol></li><li> 1ppmのアンピシリン溶液を調製します。 <ol><li> 10 mgのアンピシリン粉末を秤量し、100ppmのアンピシリン溶液を作るために100 mLの水に溶解します。 30秒間フラスコを渦。 </li><li>試験管内で100ppmの溶液1mlを取り、10 ppmのアンピシリン溶液を作製するために9ミリリットルの水を追加します。 5秒間チューブをボルテックス。 </li><li>試験管に10ppmの溶液1mlを取り、1 ppmのアンピシリン溶液を作製するために9ミリリットルの水を追加します。 5秒間チューブをボルテックス。 </li></ol></li><li> NPコーティングされた側を上に向けて、バックフィルターホルダーにフィルター膜を置きます。&lt;/李&gt; <li>その後、新しいシリンジにロード一つのサンプルの5ミリリットルを、そして内側の銀コーティングされた膜でフィルターホルダーに取り付けます。 </li><li>手動で1滴/秒の流量で膜を通してサンプルのボリューム全体を渡します。標的分子は、フィルター膜上に塗布されたNPを吸着させ、濃縮することができます。 </li><li> 、フィルターホルダーからフィルタ膜を取り外し、約3分間空気乾燥し、ステップ2.6に記載したのと同じ方法を用いて、ラマン装置を使用して信号を測定します。 </li><li>別の銀コーティングされた膜を作成し、他のサンプルの検出のためのステップ3.3から追従する2.6を繰り返しステップ2.2。 </li></ol>

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P., He, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+surface-enhanced+Raman+scattering+detection+using+a+handheld+and+a+bench-top+Raman+spectrometer:+A+comparative+study.">Evaluation of surface-enhanced Raman scattering detection using a handheld and a bench-top Raman spectrometer: A comparative study.</a> Talanta. 129, 79-85 (2014).</li></ol>

The authors have nothing to disclose.

このプロトコルにおいて重要なステップの一つは、均一のAg NPは一貫性のある結果を得るための鍵である銀のNP合成、です。加熱時間及び前駆体の濃度を正確に制御しなければなりません。このAgNPs製剤の平均サイズはゼータサイザーで測定した80ナノメートルである（データは示さず）。別の重要なステップは、塩濃度及び凝集時間を正確に制御しなければならない塩の集合体です。小さい細孔径を有する膜は、トラップのAgナノクラスターへのより効果的であることが見出されたように加えて、膜の選択も重要です。本研究で使用される特定の膜は、正面側のシリンジを接続するホルダー中に配置しなければならない前面及び裏面があります。それは下に置かれた場合には、コーティングは、それほど効果的でした。膜を通過する際に気泡を回避することは、成功したコーティングに別のキーです。 このアッセイのトラブルシューティングのために、次の手順推奨されています。何か少しシグナルが検出されない場合、以下の原因を確認してください。主な原因は、Ag NPはフィルター膜の細孔中に閉じ込めされるのに十分に集約されていない可能性があります。塩濃度および/またはインキュベーション時間を増加させると、凝集を増強することができます。それ以外の場合は、フィルター膜の裏側を上に向け、および膜上に負荷サンプルの体積または濃度が低すぎないことをされていることを確認してください。標的分子の信号が一貫していない場合は、次の原因をチェック：銀のNPのサイズ分布が広すぎるであってもよいし、NPのが均等におそらくあまりにも多くのNPの凝集や速すぎると、膜上に分布していません膜を通過します。 SERS基板としてのAg樹状突起の使用に関する我々の以前のデータ、30-31と比較すると、このフィルタベースのSERSアッセイの感度はフェルバム検出に非常に高いです。これはラを流すことができるフィルターベースのシステムの利点によるものですサンプルのRGE量、より多くの分析物分子がSERS基板上に集中するようになっています。いかなる遠心分離は、NP-分析物複合体を収集するために必要とされないように、溶液ベースの方法を介してフィルタベースのシステムを使用する別の利点は、動作およびfieldable測定の容易さです。この方法の制限は、複雑なコンポーネントが膜孔をブロックすることができるようにそれは、そのような直接牛乳のような複雑な液体マトリックスのために使用することはできないです。前処理は、膜を通過する前に、妨害成分を除去するために必要とされます。 要約すると、我々は、液体食品マトリックス及び環境試料中の汚染物質またはadulterationsの検出に適用することができる簡単かつ敏感なフィルタベースのSERSアッセイを実証します。さらに、検出の限界をプッシュするために、NPのサイズと量、塩濃度、サンプル体積と機器パラメータなどのパラメータの最適化が必要です。

表面増強ラマン分光法（SERS）は、ナノテクノロジーを用いて、ラマン分光法を組み合わせた手法です。貴金属ナノ表面における検体のラマン散乱光の強度が大幅に局在表面プラズモン共鳴により増強される。1銀ナノ粒子（銀NPS）その高い拡張能力をはるかに最も広く使用されているSERS用基板である。今まで2 Ag NPの様々な合成方法が開発されている。3-6のAg NPは、その感度および/ ​​または機能を増強するのに有効なSERS基板として単独で使用、または他の材料及び構造と組み合わせることができる。7-11 SERS技術は、食品や環境試料中の様々な微量汚染物質の検出のための偉大な能力を実証している12は伝統的に、SERSのサンプルを調製するための2つの一般的な方法があります：。。溶液系と基板ベースの方法は、13 ソリューションベースのメ​​トdは、サンプルと混合するNPコロイドを使用しています。次にNP - 分析物複合体は、遠心分離を用いて回収し、乾燥後のラマン測定のための固体支持体上に堆積されます。基板ベースの方法は、通常、事前に作製した固体基板上に液体試料のいくつかのマイクロリットルを堆積させることによって適用される。14が、これら2つの方法のいずれもが、試料容量の大量のために有効かつ適用可能です。 SERSアッセイのいくつかの変更は、フィルターシステム15-21またはマイクロ流体デバイスの組み込みの統合などの音量制限を、克服した。21-24修正されたSERSアッセイは、化学汚染物質を監視するための感度と実現可能性に大きな向上を示しています大規模な水サンプルインチここでは、農薬フェルバムおよび抗生物質アンピシリンの微量を検出するために製造およびシリンジフィルターベースのSERS法の適用の詳細なプロトコルを示します。

<table border="0" cellpadding="0" cellspacing="0" width="604">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Ampicillin</td>
			<td style="width:128px;">Fisher Scientific</td>
			<td style="width:136px;">BP1760-5</td>
			<td style="width:131px;">N/A</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Ferbam</td>
			<td style="width:128px;">Chem Service</td>
			<td style="width:136px;">N-11970-250MG</td>
			<td style="width:131px;">98+%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Silver nitrate</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:136px;">209139</td>
			<td style="width:131px;">99.0+%</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:211px;">Sodium citrate dehydrate</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:136px;">W302600</td>
			<td style="width:131px;">99+%</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:211px;">Sodium chloride</td>
			<td style="width:128px;">Sigma Aldrich</td>
			<td style="width:136px;">S7653</td>
			<td style="width:131px;">99.5+%</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:211px;">EMD Millipore Durapore PVDF Membrane Filters</td>
			<td style="width:128px;">Fisher Scientific</td>
			<td style="width:136px;">VVLP01300</td>
			<td style="width:131px;">0.10 &#181;m Pore Size, hydrophilic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:211px;">Polycarbonate Filter Holders</td>
			<td style="width:128px;">Cole-Parmer</td>
			<td style="width:136px;">EW-29550-40</td>
			<td style="width:131px;">13 mm diameter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Analog Vortex Mixer</td>
			<td style="width:128px;">Fisher Scientific</td>
			<td>02-215-365</td>
			<td>N/A</td>
		</tr>
		<tr height="50">
			<td height="50" style="height:51px;width:211px;">Nutating Mixers</td>
			<td style="width:128px;">Fisher Scientific</td>
			<td>05-450-213</td>
			<td style="width:131px;">N/A</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:211px;">DXR Raman spectroscope</td>
			<td style="width:128px;">Thermo Scientific</td>
			<td style="width:136px;">IQLAADGABFFAHCMAPB</td>
			<td style="width:131px;">Laser power: 1 mW Exposure time: 5 s</td>
		</tr>
	</tbody>
</table>

a filter-based surface enhanced raman spectroscopic assay for rapid detection of chemical contaminants

We demonstrate a method to fabricate highly sensitive surface-enhanced Raman spectroscopic (SERS) substrates using a filter syringe system that can be applied to the detection of various chemical contaminants. Silver nanoparticles (Ag NPs) are synthesized via reduction of silver nitrate by sodium citrate. Then the NPs are aggregated by sodium chloride to form nanoclusters that could be trapped in the pores of the filter membrane. A syringe is connected to the filter holder, with a filter membrane inside. By loading the nanoclusters into the syringe and passing through the membrane, the liquid goes through the membrane but not the nanoclusters, forming a SERS-active membrane. When testing the analyte, the liquid sample is loaded into the syringe and flowed through the Ag NPs coated membrane. The analyte binds and concentrates on the Ag NPs coated membrane. Then the membrane is detached from the filter holder, air dried and measured by a Raman instrument. Here we present the study of the volume effect of Ag NPs and sample on the detection sensitivity as well as the detection of 10 ppb ferbam and 1 ppm ampicillin using the developed assay.

この実験の主要な工程を示す模式図（ 図1）に示した。2が最大感度に達するために、膜コーティングでAgNPsの最適化されたボリュームを使用する重要性を示した図 。フェルバムを使用している場合0.5ミリリットル（不十分なコーティング）または2ミリリットル（あまりにも多くのコーティング）と比較したAg NPの1ミリリットルは、最も強い信号を提供します。 我々は開発したフィルタベースのSERSアッセイ（ 図1）によって、大きな信号強度で1 ppmには10ppbレベルとアンピシリンでフェルバムを検出することができました。フェルバムのSERSスペクトルは、10 ppbので明瞭な特徴的なピークを示します。 1386センチメートル-1のピークは混合CN伸縮およびC = Sの振動、および対称CH 3変形からです。 1516センチメートル-1のピークはCH 3及びCN延伸に関連しています。 561センチメートルのピーク<sup&gt; -1 SSのストレッチによって生成される。25-27 1ppmのアンピシリンのスペクトルも明確に検出されました。 1594センチメートル-1および1447センチメートル-1のピークはC = Cはそれぞれ、ストレッチおよびCH 3 / CH 2変形からです。 1001センチメートルでの強いピークは-1ベンゼン環の振動からです。 852 cm -1でのピークは、対称CNC延伸に関連付けられている。28-29を一つの試料を分析するための実験時間は、予め合成されたAg NPを有するSERS活性フィルター膜の製造などの20分未満です。 図4に示すように、サンプル容量の増加に伴って、我々はさらに、検出限界を高めることができる。サンプル容量を増加させるときに我々は、ピーク強度の増加を観察しました。ボリュームが調整可能であり、検出限界にも調整可能であるので、これは、フィルタベースの方法の利点です。 ether.within-ページ= &quot;1&quot;&gt; <img alt="図1" src="/files/ftp_upload/53791/53791fig1.jpg" /> 図1. フィルターSERSアッセイの概略図。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53791/53791fig1large.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2" src="/files/ftp_upload/53791/53791fig2.jpg" /> 5ミリリットルが100ppbの 図2. SERSスペクトルは、Ag NPの異なる量によってコーティングされた膜を通過フェルバム上から下へ：1.0ミリリットルのNaClを0.5ミリリットルのNaClを0.5ミリリットル銀コロイド、1.0ミリリットルのAg、1.5と1.5ミリリットルのAg mlのNaClが、それぞれ。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53791/53791fig2large.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> 91 / 53791fig3.jpg &quot;/&gt; 銀のNPコーティングされたフィルター膜上フェルバムとアンピシリンの 図3. SERSスペクトル上から下まで：50％アセトニトリルの制御、10ppbののフェルバム、水の制御、1 ppmのアンピシリン、それぞれ<a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53791/53791fig3large.jpg" target="_blank">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。この図。</a> <img alt="図4" src="/files/ftp_upload/53791/53791fig4.jpg" /> 銀のNPコーティングされたフィルター膜上が100ppbのフェルバムの異なるボリュームの 図4. SERSスペクトル上から下へ：3ミリリットルフェルバム、5ミリリットルフェルバム、7ミリリットルフェルバム、9ミリリットルフェルバム、それぞれ。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/53791/53791fig4large.jpg" target="_blank">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。この図の。</a>

Watch this Scientific Journal Video about A Filter-based Surface Enhanced Raman Spectroscopic Assay for Rapid Detection of Chemical Contaminants at JoVE.com

A Filter-based Surface Enhanced Raman Spectroscopic Assay for Rapid Detection of Chemical Contaminants

製造や化学汚染物質（ すなわち、農薬フェルバムと抗生物質アンピシリン）の検出のためのラマン分光（SERS）アッセイ強化フィルタベースの表面を実行するための手順が提示されています。

化学汚染物質の迅速検出のためのラマン分光アッセイ強化フィルターベースの表面

We demonstrate a method to fabricate highly sensitive surface-enhanced Raman spectroscopic (SERS) substrates using a filter syringe system that can be ...

a-filter-based-surface-enhanced-raman-spectroscopic-assay-for-rapid

Nanyang Technological University

Research

JoVE Journal

Chemistry

9.3K ビュー.  University of Massachusetts Amherst. 製造や化学汚染物質（ すなわち、農薬フェルバムと抗生物質アンピシリン）の検出のためのラマン分光（SERS）アッセイ強化フィルタベースの表面を実行するための手順が提示されています。 

ビデオ: A Filter-based Surface Enhanced Raman Spectroscopic Assay for Rapid Detection of Chemical Contaminants

Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high surface area microporous materials, such as metal-organic frameworks (MOFs), unique challenges present themselves for PECVD treatments. Herein the protocol for development of a MOF that was previously unstable to humid conditions is presented. The protocol describes the synthesis of Cu-BTC (also known as HKUST-1), the treatment of Cu-BTC with PECVD of perfluoroalkanes, the aging of materials under humid conditions, and the subsequent ammonia microbreakthrough experiments on milligram quantities of microporous materials. Cu-BTC has an extremely high surface area (~1,800 m2/g) when compared to most materials or surfaces that have been previously treated by PECVD methods. Parameters such as chamber pressure and treatment time are extremely important to ensure the perfluoroalkane plasma penetrates to and reacts with the inner MOF surfaces. Furthermore, the protocol for ammonia microbreakthrough experiments set forth here can be utilized for a variety of test gases and microporous materials.

Herein the procedures for plasma enhanced chemical vapor deposition of perfluoroalkanes on microporous materials such as metal-organic frameworks to enhance their stability and hydrophobicity are described. Furthermore, breakthrough testing of milligram quantities of samples is described in detail.

プラズマを介した疎水性有機金属フレームワークの製造は、アンモニアの除去のためにペルフルオロアルカンの化学的気相成長法を強化

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high ...

化学

A Simple and Rapid Protocol for Measuring Neutral Lipids in Algal Cells Using Fluorescence

Algae are considered excellent candidates for renewable fuel sources due to their natural lipid storage capabilities. Robust monitoring of algal fermentation processes and screening for new oil-rich strains requires a fast and reliable protocol for determination of intracellular lipid content. Current practices rely largely on gravimetric methods to determine oil content, techniques developed decades ago that are time consuming and require large sample volumes. In this paper, Nile Red, a fluorescent dye that has been used to identify the presence of lipid bodies in numerous types of organisms, is incorporated into a simple, fast, and reliable protocol for measuring the neutral lipid content of Auxenochlorella protothecoides, a green alga. The method uses ethanol, a relatively mild solvent, to permeabilize the cell membrane before staining and a 96 well micro-plate to increase sample capacity during fluorescence intensity measurements. It has been designed with the specific application of monitoring bioprocess performance. Previously dried samples or live samples from a growing culture can be used in the assay.

A simple protocol to determine the neutral lipid content of algal cells using a Nile Red staining procedure is described. This time-saving technique offers an alternative to traditional gravimetric-based lipid quantification protocols. It has been designed for the specific application of monitoring bioprocess performance.

蛍光を用いて藻体で中性脂肪を測定するための簡単​​かつ迅速なプロトコル

Algae are considered excellent candidates for renewable fuel sources due to their natural lipid storage capabilities. Robust monitoring of algal ...

Preparation of Highly Porous Coordination Polymer Coatings on Macroporous Polymer Monoliths for Enhanced Enrichment of Phosphopeptides

We describe a protocol for the preparation of hybrid materials based on highly porous coordination polymer coatings on the internal surface of macroporous polymer monoliths. The developed approach is based on the preparation of a macroporous polymer containing carboxylic acid functional groups and the subsequent step-by-step solution-based controlled growth of a layer of a porous coordination polymer on the surface of the pores of the polymer monolith. The prepared metal-organic polymer hybrid has a high specific micropore surface area. The amount of iron(III) sites is enhanced through metal-organic coordination on the surface of the pores of the functional polymer support. The increase of metal sites is related to the number of iterations of the coating process.
The developed preparation scheme is easily adapted to a capillary column format. The functional porous polymer is prepared as a self-contained single-block porous monolith within the capillary, yielding a flow-through separation device with excellent flow permeability and modest back-pressure. The metal-organic polymer hybrid column showed excellent performance for the enrichment of phosphopeptides from digested proteins and their subsequent detection using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The presented experimental protocol is highly versatile, and can be easily implemented to different organic polymer supports and coatings with a plethora of porous coordination polymers and metal-organic frameworks for multiple purification and/or separation applications.

A procedure for the preparation of porous hybrid separation media composed of a macroporous polymer monolith internally coated by a high surface area microporous coordination polymer is presented.

リン酸化ペプチドの強化充実のためのマクロポーラスポリマーモノリスの高度に多孔性配位高分子コーティングの製造

We describe a protocol for the preparation of hybrid materials based on highly porous coordination polymer coatings on the internal surface of macroporous ...

A Method to Manipulate Surface Tension of a Liquid Metal via Surface Oxidation and Reduction

Controlling interfacial tension is an effective method for manipulating the shape, position, and flow of fluids at sub-millimeter length scales, where interfacial tension is a dominant force. A variety of methods exist for controlling the interfacial tension of aqueous and organic liquids on this scale; however, these techniques have limited utility for liquid metals due to their large interfacial tension.
Liquid metals can form soft, stretchable, and shape-reconfigurable components in electronic and electromagnetic devices. Although it is possible to manipulate these fluids via mechanical methods (e.g., pumping), electrical methods are easier to miniaturize, control, and implement. However, most electrical techniques have their own constraints: electrowetting-on-dielectric requires large (kV) potentials for modest actuation, electrocapillarity can affect relatively small changes in the interfacial tension, and continuous electrowetting is limited to plugs of the liquid metal in capillaries.
Here, we present a method for actuating gallium and gallium-based liquid metal alloys via an electrochemical surface reaction. Controlling the electrochemical potential on the surface of the liquid metal in electrolyte rapidly and reversibly changes the interfacial tension by over two orders of magnitude ( &#820;500 mN/m to near zero). Furthermore, this method requires only a very modest potential (&#60; 1 V) applied relative to a counter electrode. The resulting change in tension is due primarily to the electrochemical deposition of a surface oxide layer, which acts as a surfactant; removal of the oxide increases the interfacial tension, and vice versa. This technique can be applied in a wide variety of electrolytes and is independent of the substrate on which it rests.

We present a method to control the interfacial energy of a liquid metal in an electrolyte via electrochemical deposition (or removal) of a surface oxide layer. This simple method can control the capillary behavior of gallium-based liquid metals by tuning the interfacial energy rapidly, significantly, and reversibly using modest voltages.

表面酸化と還元を経て液体金属の表面張力を操作する方法

Controlling interfacial tension is an effective method for manipulating the shape, position, and flow of fluids at sub-millimeter length scales, where ...

Preparation of Biopolymer Aerogels Using Green Solvents

Although the first reports on aerogels made by Kistler1 in the 1930s dealt with aerogels from both inorganic oxides (silica and others) and biopolymers (gelatin, agar, cellulose), only recently have biomasses been recognized as an abundant source of chemically diverse macromolecules for functional aerogel materials. Biopolymer aerogels (pectin, alginate, chitosan, cellulose, etc.) exhibit both specific inheritable functions of starting biopolymers and distinctive features of aerogels (80-99% porosity and specific surface up to 800 m2/g). This synergy of properties makes biopolymer aerogels promising candidates for a wide gamut of applications such as thermal insulation, tissue engineering and regenerative medicine, drug delivery systems, functional foods, catalysts, adsorbents and sensors. This work demonstrates the use of pressurized carbon dioxide (5 MPa) for the ionic cross linking of amidated pectin into hydrogels. Initially a biopolymer/salt dispersion is prepared in water. Under pressurized CO2 conditions, the pH of the biopolymer solution is lowered to 3 which releases the crosslinking cations from the salt to bind with the biopolymer yielding hydrogels. Solvent exchange to ethanol and further supercritical CO2 drying (10 - 12 MPa) yield aerogels. Obtained aerogels are ultra-porous with low density (as low as 0.02 g/cm3), high specific surface area (350 - 500 m2/g) and pore volume (3 - 7 cm3/g for pore sizes less than 150 nm).

A new way for the production of biopolymer-based aerogels by carbon dioxide (CO2) induced gelation is shown. The technique utilizes pressurized carbon dioxide (5 MPa) for the production of biopolymer hydrogels and supercritical CO2 (12 MPa) to convert gels into aerogels. The only solvents needed besides CO2 are water and ethanol.

グリーン溶剤を使用したバイオポリマーエアロゲルの調製

Although the first reports on aerogels made by Kistler1 in the 1930s dealt with aerogels from both inorganic oxides (silica and others) and biopolymers ...

A Novel Technique for Raman Analysis of Highly Radioactive Samples Using Any Standard Micro-Raman Spectrometer

A novel approach for the Raman measurement of nuclear materials is reported in this paper. It consists of the enclosure of the radioactive sample in a tight capsule that isolates the material from the atmosphere. The capsule can optionally be filled with a chosen gas pressurized up to 20 bars. The micro-Raman measurement is performed through an optical-grade quartz window. This technique permits accurate Raman measurements with no need for the spectrometer to be enclosed in an alpha-tight containment. It therefore allows the use of all options of the Raman spectrometer, like multi-wavelength laser excitation, different polarizations, and single or triple spectrometer modes. Some examples of measurements are shown and discussed. First, some spectral features of a highly radioactive americium oxide sample (AmO2) are presented. Then, we report the Raman spectra of neptunium oxide (NpO2) samples, the interpretation of which is greatly improved by employing three different excitation wavelengths, 17O doping, and a triple mode configuration to measure the anti-stokes Raman lines. This last feature also allows the estimation of the sample surface temperature. Finally, data that were measured on a sample from Chernobyl lava, where phases are identified by Raman mapping, are shown.

We present a technique for Raman spectroscopic analysis of highly radioactive samples compatible with any standard micro-Raman spectrometer, without any radioactive contamination of the instrument. We also show some applications using actinide compounds and irradiated fuel materials.

任意の標準的な顕微ラマン分光計を用いて高レベル放射性サンプルのラマン分析のための新規な技術

A novel approach for the Raman measurement of nuclear materials is reported in this paper. It consists of the enclosure of the radioactive sample in a ...

Observation and Analysis of Blinking Surface-enhanced Raman Scattering

From a single molecule at a silver nanoaggregate junction, blinking surface-enhanced Raman scattering (SERS) is observed. Here, a protocol is presented on how to prepare the SERS-active silver nanoaggregate, record a video of certain blinking spots in the microscopic image, and analyze the blinking statistics. In this analysis, a power law reproduces the probability distributions for bright events relative to their duration. The probability distributions for dark events are fitted by a power law with an exponential function. The parameters of the power law represent molecular behavior in both bright and dark states. The random walk model and the speed of the molecule across the entire silver surface can be estimated. It is difficult to estimate even when using averages, autocorrelation functions, and super-resolution SERS imaging. In the future, power law analyses should be combined with spectral imaging, because the origins of blinking cannot be confirmed by this analysis method alone.

This protocol describes the analysis of blinking surface-enhanced Raman scattering due to the random walk of a single molecule on a silver surface using power laws.

点滅表面増強ラマン散乱の観測と解析

From a single molecule at a silver nanoaggregate junction, blinking surface-enhanced Raman scattering (SERS) is observed. Here, a protocol is presented on ...

Color Spot Test As a Presumptive Tool for the Rapid Detection of Synthetic Cathinones

Synthetic cathinones are a large class of new psychoactive substances (NPS) that are increasingly prevalent in drug seizures made by law enforcement and other border protection agencies globally. Color testing is a presumptive identification technique indicating the presence or absence of a particular drug class using rapid and uncomplicated chemical methods. Owing to their relatively recent emergence, a color test for the specific identification of synthetic cathinones is not currently available. In this study, we introduce a protocol for the presumptive identification of synthetic cathinones, employing three aqueous reagent solutions: copper(II) nitrate, 2,9-dimethyl-1,10-phenanthroline (neocuproine) and sodium acetate. Small pin-head sized amounts (approximately 0.1-0.2 mg) of the suspected drugs are added to the wells of a porcelain spot plate, and each reagent is then added dropwise sequentially before heating on a hotplate. A color change from very light blue to yellow-orange after 10 min indicates the likely presence of synthetic cathinones. The highly stable and specific test reagent has the potential for use in the presumptive screening of unknown samples for synthetic cathinones in a forensic laboratory. However, the nuisance of an added heating step for the color change result limits the test to laboratory application and decreases the likelihood of an easy translation to field testing.

Here we present a simple, inexpensive, and selective chemical spot test protocol for the detection of synthetic cathinones, a class of new psychoactive substances. The protocol is suitable for use in various areas of law enforcement that encounter illicit material.

合成 Cathinones の急速な検出のための推定ツールとして色スポット テスト

Synthetic cathinones are a large class of new psychoactive substances (NPS) that are increasingly prevalent in drug seizures made by law enforcement and ...

Gold Nanoparticle Modified Carbon Fiber Microelectrodes for Enhanced Neurochemical Detection

For over 30 years, carbon-fiber microelectrodes (CFMEs) have been the standard for neurotransmitter detection. Generally, carbon fibers are aspirated into glass capillaries, pulled to a fine taper, and then sealed using an epoxy to create electrode materials that are used for fast scan cyclic voltammetry testing. The use of bare CFMEs has several limitations, though. First and foremost, the carbon fiber contains mostly basal plane carbon, which has a relatively low surface area and yields lower sensitivities than other nanomaterials. Furthermore, the graphitic carbon is limited by its temporal resolution, and its relatively low conductivity. Lastly, neurochemicals and macromolecules have been known to foul at the surface of carbon electrodes where they form non-conductive polymers that block further neurotransmitter adsorption. For this study, we modify CFMEs with gold nanoparticles to enhance neurochemical testing with fast scan cyclic voltammetry. Au3+ was electrodeposited or dipcoated from a colloidal solution onto the surface of CFMEs. Since gold is a stable and relatively inert metal, it is an ideal electrode material for analytical measurements of neurochemicals. Gold nanoparticle modified (AuNP-CFMEs) had a stability to dopamine response for over 4 h. Moreover, AuNP-CFMEs exhibit an increased sensitivity (higher peak oxidative current of the cyclic voltammograms) and faster electron transfer kinetics (lower &#916;EP or peak separation) than bare unmodified CFMEs. The development of AuNP-CFMEs provides the creation of novel electrochemical sensors for detecting fast changes in dopamine concentration and other neurochemicals at lower limits of detection. This work has vast applications for the enhancement of neurochemical measurements. The generation of gold nanoparticle modified CFMEs will be vitally important for the development of novel electrode sensors to detect neurotransmitters in vivo in rodent and other models to study neurochemical effects of drug abuse, depression, stroke, ischemia, and other behavioral and disease states.

In this study, we modify carbon-fiber microelectrodes with gold nanoparticles to enhance the sensitivity of neurotransmitter detection.

強化された神経化学的検出のための金ナノ粒子修飾炭素繊維マイクロ電極

For over 30 years, carbon-fiber microelectrodes (CFMEs) have been the standard for neurotransmitter detection. Generally, carbon fibers are aspirated into ...

A Two-Step Pyrolysis-Gas Chromatography Method with Mass Spectrometric Detection for Identification of Tattoo Ink Ingredients and Counterfeit Products

Tattoo inks are complex mixtures of ingredients. Each of them possesses different chemical properties which have to be addressed upon chemical analysis. In this method for two-step pyrolysis online coupled to gas chromatography mass spectrometry (py-GC-MS) volatile compounds are analyzed during a first desorption run. In the second run, the same dried sample is pyrolyzed for analysis of non-volatile compounds such as pigments and polymers. These can be identified by their specific decomposition patterns. Additionally, this method can be used to differentiate original from counterfeit inks. Easy screening methods for data evaluation using the average mass spectra and self-made pyrolysis libraries are applied to speed up substance identification. Using specialized evaluation software for pyrolysis GS-MS data, a fast and reliable comparison of the full chromatogram can be achieved. Since GC-MS is used as separation technique, the method is limited to volatile substances upon desorption and after pyrolysis of the sample. The method can be applied for quick substance screening in market control surveys since it requires no sample preparation steps.

This method for two-step pyrolysis online coupled to gas chromatography with mass spectrometric detection and data evaluation protocol can be used for multi-component analysis of tattoo inks and discrimination of counterfeit products.

タトゥーインク成分および偽造製品の同定のための質量分光検出を用いた2段階熱分解-ガスクロマトグラフィー法

Tattoo inks are complex mixtures of ingredients. Each of them possesses different chemical properties which have to be addressed upon chemical analysis. ...