Agradecemos ao laboratório nacional Noroeste Pacífico (PNNL) terra e ciências biológicas (EBD) missão semente laboratório dirigido a investigação e desenvolvimento (LDRD) fundo de apoio. Acesso instrumental foi fornecido através de uma proposta de usuário geral W. R. Wiley ambiental Molecular Sciences Laboratory (EMSL). EMSL é uma instalação de usuário científico nacional patrocinada pelo escritório de biológicos e pesquisa ambiental (BER) em PNNL. Os autores agradecer Dr. Yuanzhao Ding prova lendo o manuscrito e fornecendo feedback útil. PNNL é operado pela Battelle para o DOE sob contrato DE-AC05-76RL01830.

<ol>
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Y., Yang, L., Cowin, J. P., Iedema, M., Zhu, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Systems+and+methods+for+analyzing+liquids+under+vacuum.">Systems and methods for analyzing liquids under vacuum.</a> US Patent. , (2013).</li><li>Yu, X. Y., Liu, B., Yang, L., Zhu, Z., Marshall, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic+electrochemical+device+and+process+for+chemical+imaging+and+electrochemical+analysis+at+the+electrode-liquid+interface+in+situ.">Microfluidic electrochemical device and process for chemical imaging and electrochemical analysis at the electrode-liquid interface in situ.</a> US Patent. , (2014).</li><li>Yang, L., Yu, X. Y., Zhu, Z. H., Thevuthasan, T., Cowin, J. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Effects of Electron-Transport-System Impairment on Hydrogen Gas Production by the Bacterium Shewanella oneidensis MR-1. , (2007).</li><li>McCormick, A. 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Os autores não têm nada para divulgar.

Após inocular em fase de registro, é importante testar o número de dias e a temperatura na qual o biofilme deve crescer antes que seja saudável e grossa o suficiente para a imagem latente, conforme descrito na etapa 3.1. Este procedimento abrange especificamente cultivo um S. oneidensis MR1 biofilme à temperatura ambiente; no entanto, diferentes temperaturas de quarto pode influenciar a taxa de crescimento. Portanto, é fundamental usar imagens ópticas para entender se o biofilme está pronto antes de proceder à a...

Biofilmes bacterianos são comunidades associadas a superfície que evoluíram ao longo do tempo como uma defesa para que as bactérias sobrevivem variando adversos estímulos físicos e mecânicos, em que células são capazes de unir e sobreviver em muitos ambientes de possíveis. 1 , 2 biofilmes são vastamente investigados e têm aplicações em muitos campos tais como biomedicina, Engenharia Biomédica, agricultura e investigação industrial e desenvolvimento. 1 , 2 compreender o mapeamento químico dessas comunidades microbianas complexas, incluindo suas auto-produzido substâncias poliméricas extracelulares (EPS) e o seu ambiente de cluster de água local, é essencial para ganhar uma exata e detalhada Descrição de suas atividades biológicas. 2
Biofilmes existirem e crescem dentro de um estado altamente hidratado. Isto representa um grande desafio na utilização de técnicas de análise de superfície baseada em vácuo como espectrometria de massa de iões secundário de tempo-de-voo (ToF-SIMS) devido à dificuldade em estudar líquidos voláteis no vácuo. Como resultado, técnicas de análise de superfície baseada em vácuo tem sido limitadas quase exclusivamente ao estudo de amostras de biofilme em apenas seu estado seco. No entanto, estudar um biofilme no seu estado seco inibe a investigação exata de sua verdade biológica microambiente. Muitas vezes provoca mudanças drásticas para a morfologia de integridade e biofilme EPS, que demonstrou-se depois de comparar resultados massa espectral biofilme seco em situ estudos líquido. 3 , 4 este artigo apresenta uma solução para o estudo de biofilmes dentro de seu estado hidratado natural empregando o uso de nosso sistema para análise na Interface líquido de vácuo (SALVI),5,6 um reator microfluidic que contém líquido sob sua membrana de nitreto (pecado) de silicone fina em um microchannel feita de polidimetilsiloxano (SPDM), proporcionando acesso directo ao feixe de íon secundário de sonda, mantendo a integridade estrutural da matriz líquido dentro de um vácuo Câmara. 7 , 8
S. oneidensis MR-1 mutado para expressar a proteína fluorescência verde (GFP) foi escolhido como um organismo modelo para esta ilustração do procedimento de biofilme devido à sua versatilidade metabólica e uso comum em microbiologia ambiental e aplicada, que foi baseado fortemente na sua capacidade única para redução de metal e a transferência de elétrons extracelular. 9 , 10 , 11 além disso, a presença de GFP permitido para fácil espessura biofilme contínua monitoramento através de microscopia de fluorescência, utilizando um filtro (FITC) de isotiocianato de fluoresceína. Nossos estudos anteriores mostraram evidências desta bactéria, favorecendo o apego à janela pecado utilizando em operando imagens de fluorescência para o crescimento do biofilme para uma espessura de até 100 micrômetros. 4 , 12 enquanto este artigo discutirá apenas a confirmação da presença do biofilme através de microscopia de fluorescência, a SALVI é compatível com outros métodos de imagem ópticos como super-resolução fluorescência imagem latente (ou seja, estruturada iluminação microscopia (SIM),9) e laser confocal, microscopia (CLSM) imagem4). Imagem latente ótica pode servir para medir a espessura do biofilme e obter uma imagem 3D, da forma do biofilme como parece, confirmando a sua espessura e a sua fixação para a janela do pecado. 9 enquanto GFP foi usado na análise SIMS, s. oneidensis sem GFP foi utilizado para a curva de crescimento, como esta única medida necessária de densidade óptica e não exigem qualquer imagem fluorescente. Geralmente, a diferença entre o GFP marcados e espécies não marcados na curva de crescimento é insignificante. Além disso, enquanto este protocolo usa S. oneidensis MR-1 GFP como um organismo modelo para descrever o procedimento, este procedimento é projetado para qualquer estirpe bacteriana que pode ser necessário para o cultivo dentro SALVI. Embora, dado o conhecimento da estirpe bacteriana necessária, algumas condições de crescimento, tais como tempo, temperatura e oxigênio ambiente talvez precise ser modificado para acomodar a cepa de bactérias para ser usado. Por meio de crescimento, este procedimento usa "nanofios" médio, tryptic soy caldo de carne (TSB) sem glicose e tryptic soy agar (TSA) sem glicose para cultivo. A composição do meio de "nanofios", foi especialmente formulada para o crescimento e para o monitoramento de extensões da membrana e periplasm de S. oneidensis que parecem tomar a forma de pequenos fios e a composição média tem sido estabelecida na pesquisa anterior. 13 , 14
Nosso protocolo anterior em in situ ToF-SIMS líquido ilustrou o benefício que SALVI tem para oferecer para imobilização de proteínas e acessório para o pecado, bem como um protocolo detalhado na redução de dados e análise de ToF-SIMS. 12 em vez de reiterar as etapas de redução de dados, este documento servirá para em vez disso, focar a abordagem única de criação e cultivando biofilmes dentro nosso microchannel SALVI, bem como as etapas de imagem para detectar a presença de biofilme e espessura prévia a análise de ToF-SIMS. Enquanto biofilmes têm sido anteriormente limitados a apenas secas amostras dentro da câmara de técnicas analíticas de superfície baseada em vácuo, mapeamento detalhado EPS e biofilme químico de biofilmes ao vivo agora pode ser obtido em situ por causa deste novo recurso.

<table width="2446">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">ToF-SIMS</td>
			<td style="width:260px;">IONTOF</td>
			<td style="width:123px;">TOF.SIMS 5</td>
			<td style="width:1675px;">Resolution:&#62;10,000 m/&#916;m for mass resolution;&#62;4,000 m/&#916;m for high spatial resolution</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">System for Analysis at the Liquid Vacuum Interface (SALVI)</td>
			<td style="width:260px;">Pacific Northwest National Laboratory</td>
			<td style="width:123px;">N/A</td>
			<td>SALVI is a unique, self-contained, portable analytical tool that, for the first time, enables vacuum based scientific instruments such as time-of-flight secondary ion mass spectrometry (ToF-SIMS) to analyze liquid surfaces in their natural state at the molecular level.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">-80&#176;C Freezer</td>
			<td style="width:260px;">New Brunswick Scientific</td>
			<td style="width:123px;">N/A</td>
			<td>U410 Premium Energy Efficient Ultra-Low Temperature Freezer</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">4&#176;C Refrigerator</td>
			<td style="width:260px;">BioCold Scientific</td>
			<td style="width:123px;">N/A</td>
			<td>COLDBOX1</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Orbital Shaker</td>
			<td style="width:260px;">New Brunswick Scientific</td>
			<td style="width:123px;">N/A</td>
			<td style="width:1675px;">Innova 4900 Multi-Tier Environmental Shaker, set at 30 degrees Celsius for serum bottle and flask culturing, set at 150rpm.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Syringe Pump</td>
			<td style="width:260px;">Cole-Parmer</td>
			<td style="width:123px;">EW-74905-02</td>
			<td>Cole-Parmer Syringe Pump, Infusion Only, Touchscreen Control 74905-02, used for injecting liquid into the tubing system and SALVI at a constant flowrate.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Incubator</td>
			<td style="width:260px;">Barnstead International</td>
			<td style="width:123px;">LT1465X3</td>
			<td>Lab-Line incubator, set at 30 degrees Celsius for plate culturing.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Autoclave</td>
			<td style="width:260px;">Getinge</td>
			<td style="width:123px;">533LS</td>
			<td>Used to sterilize PEEK fittings, tubing systems, serum vials, and medium. Model 533LS Vacuum Steam Sterilizer</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Spectrophotometer</td>
			<td style="width:260px;">Thermo Fisher Scientific</td>
			<td style="width:123px;">4001-000</td>
			<td>GENESYS 20 spectrophotometer for OD600 readings of cuvettes for growth curves.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Biological Safety Cabinet</td>
			<td style="width:260px;">Thermo Fisher Scientific</td>
			<td style="width:123px;">1385</td>
			<td>1300 Series AZ Biological Safety Cabinet</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Fluorescence Microscope</td>
			<td style="width:260px;">Nikon</td>
			<td style="width:123px;">N/A</td>
			<td>Nikon OPTIPHOT-2 fluorescence microscope with camera and super high pressure mercury lamp power supply.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">pH Meter</td>
			<td style="width:260px;">Mettler Toledo</td>
			<td style="width:123px;">51302803</td>
			<td>Used to test the pH of the &#8220;nanowires&#8221; medium after finished and before autoclaving.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">PEEK Union</td>
			<td style="width:260px;">Valco</td>
			<td style="width:123px;">ZU1TPK</td>
			<td>For connecting the inlet and outlet of SALVI, the syringe to the tubing system, and the inlet of the SALVI to the drip chamber of the tubing system.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">5 Axes Sample Stage</td>
			<td style="width:260px;">IONTOF</td>
			<td style="width:123px;">N/A</td>
			<td>Stage is self-made for mounting SALVI in ToF-SIMS.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Barnstead Nanopure Water Purification System</td>
			<td style="width:260px;">Thermo Fisher Scientific</td>
			<td style="width:123px;">D11921</td>
			<td>ROpure LP Reverse Osmosis filtration module (D2716)</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Pipette</td>
			<td style="width:260px;">Thermo Fisher Scientific</td>
			<td style="width:123px;">21-377-821</td>
			<td>Range: 100 to 1,000 &#181;L.</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Pipette Tip</td>
			<td style="width:260px;">Neptune</td>
			<td style="width:123px;">2112.96.BS</td>
			<td>1,000 &#181;L pipette tips</td>
		</tr>
		<tr height="20">
			<td height="20" style="width:389px;height:20px;">Razor Blade Handle</td>
			<td style="width:260px;">Stanley</td>
			<td style="width:123px;">N/A</td>
			<td>Stanley Bostitch Razor Blade Scraper with 5 Single-Edge Blades, used for cutting PTFE tubing</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Syringe</td>
			<td style="width:260px;">BD</td>
			<td style="width:123px;">309659</td>
			<td>1 mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Syringe</td>
			<td style="width:260px;">BD</td>
			<td style="width:123px;">309657</td>
			<td>3 mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Syringe</td>
			<td style="width:260px;">BD</td>
			<td style="width:123px;">309646</td>
			<td>5 mL; Used for making the drip chamber</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Syringe</td>
			<td style="width:260px;">BD</td>
			<td style="width:123px;">309604</td>
			<td>10 mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Syringe</td>
			<td style="width:260px;">BD</td>
			<td style="width:123px;">302830</td>
			<td>20 mL</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Disposable Pipette</td>
			<td style="width:260px;">Thermo Fisher Scientific</td>
			<td style="width:123px;">13-678-11</td>
			<td>25 mL Fisherbrand&#8482; Sterile Polystyrene Disposable Serological Pipets with Magnifier Stripe, for filling serum bottles.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Electric Pipette Filler</td>
			<td style="width:260px;">Pipet-aid</td>
			<td style="width:123px;">P-57260</td>
			<td>Vacuum pressure electric serological pipette filler</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Serum Bottle</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">33109-U</td>
			<td>Holds approximately 69 mL of liquid for culture growth, optimum for use of 20mL culture per bottle.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Anaerobic Culture Tube</td>
			<td style="width:260px;">VWR</td>
			<td style="width:123px;">89167-178</td>
			<td>Anaerobic Tubes, 18 x 150 mm, Supplied with 20 mm Blue Butyl Rubber Stopper and Aluminum Seal.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Rubber Stopper</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">27235-U</td>
			<td>Silicone stopper, used for sealing serum bottles and for creating the tubing system/drip chamber.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Aluminum Crimp Seal (without septum)</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">27227-U</td>
			<td>Aluminum seal for top of serum bottle for use with serum bottle crimper.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Serum Bottle Aluminum Seal Crimper</td>
			<td style="width:260px;">Wheaton</td>
			<td style="width:123px;">224307</td>
			<td>30 mm crimper with standard seal.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">PTFE Tubing</td>
			<td style="width:260px;">Supelco</td>
			<td style="width:123px;">58697-U</td>
			<td>1.58 mm OD x 0.5 mm ID 50 ft. PTFE Teflon tubing, used for creating the tubing system.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Disposable Cuvettes</td>
			<td style="width:260px;">GMBH</td>
			<td style="width:123px;">759085D</td>
			<td>1.5 Ml for use with spectrophotometer.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Needle</td>
			<td style="width:260px;">BD</td>
			<td style="width:123px;">303015</td>
			<td>22G; used for serum bottle injection.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Needle</td>
			<td style="width:260px;">BD</td>
			<td style="width:123px;">305120</td>
			<td>23G; used for punching-through rubber stopper to create drip tubing system.</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Shewanella oneidensis MR-1 with GFP</td>
			<td style="width:260px;">N/A</td>
			<td style="width:123px;">N/A</td>
			<td>Matthysse AG, Stretton S, Dandie C, McClure NC, &#38; Goodman AE (1996) Construction of GFP vectors for use in Gram-negative bacteria other than Escherichia coli. FEMS Microbiol Lett 145(1):87-94.&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Ethanol</td>
			<td style="width:260px;">Thermo Fisher Scientific</td>
			<td style="width:123px;">&#160;S25310A</td>
			<td>95% Denatured</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">TSA</td>
			<td style="width:260px;">BD</td>
			<td style="width:123px;">212305</td>
			<td>Tryptic soy agar for culturing the model organism (S. oneidensis) used in this protocol</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">PIPES Buffer</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">P-1851</td>
			<td>Used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Sodium Hydroxide</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">S-5881</td>
			<td>Used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Ammonium Chloride</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">A-5666</td>
			<td>Used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Potassium Chloride</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">P-4504</td>
			<td>Used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Sodium Phosphate Monobasic</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">S-9638</td>
			<td>Used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Sodium Chloride</td>
			<td style="width:260px;">Thermo Fisher Scientific</td>
			<td style="width:123px;">S271-3</td>
			<td>Used for &#8220;nanowires&#8221; medium, and used to make mineral solution used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Sodium lactate</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">L-1375</td>
			<td>60%(w/w) syrup @ 98% pure, d=1.3 g/mL, 7M, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Sodium Bicarbonate</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">S-5761</td>
			<td>Used to make ferric NTA solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Nitrilotriacetic Acid Trisodium Salt</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">N-0253</td>
			<td>Used to make ferric NTA solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Iron (III) Chloride</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">451649</td>
			<td>Used to make ferric NTA solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Magnesium Sulfate</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">208094</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Manganese (II) Sulfate Monohydrate</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">M-7634</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Iron(II) Sulfate Heptahydrate</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">215422</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Calcium Chloride Dihydrate</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">223506</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Cobalt(II) Chloride</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">60818</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Zinc Chloride</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">229997</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Copper(II) Sulfate Pentahydrate</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">C-8027</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Aluminum Potassium Sulfate Dodecahydrate</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">237086</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Boric Acid</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">B-6768</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Sodium Molybdate Dihydrate</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">331058</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Nickel(II) Chloride</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">339350</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Sodium Tungstate Dihydrate</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">14304</td>
			<td>Used to make minerals solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">D-Biotin</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">47868</td>
			<td>Used to make vitamin solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Folic Acid</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">F-7876</td>
			<td>Used to make vitamin solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Pyridoxine Hydrochloride</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">P-9755</td>
			<td>Used to make vitamin solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Riboflavin (B2)</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">47861</td>
			<td>Used to make vitamin solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Thiamine Hydrochloride</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">T-4625</td>
			<td>Used to make vitamin solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Nicotinic Acid</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">N4126</td>
			<td>Used to make vitamin solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">D-Pantothenic Acid Hemicalcium Salt</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">21210</td>
			<td>Used to make vitamin solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Vitamin B12</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">V-2876</td>
			<td>Used to make vitamin solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">4-Aminobenzoic Acid</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">A-9878</td>
			<td>Used to make vitamin solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:389px;height:21px;">Thioctic Acid</td>
			<td style="width:260px;">Sigma</td>
			<td style="width:123px;">T-1395</td>
			<td>Used to make vitamin solution, used for &#8220;nanowires&#8221; medium {Hill, E.A. 2007}</td>
		</tr>
	</tbody>
</table>

in situ characterization of shewanella oneidensis mr1 biofilms by salvi and tof-sims

Biofilmes bacterianos são comunidades de superfície associadas que são vastamente estudadas para entender suas auto-produzido substâncias poliméricas extracelulares (EPS) e seus papéis em microbiologia ambiental. Este estudo descreve um método para cultivar apego de biofilme no sistema para análise na Interface líquido de vácuo (SALVI) e alcançar em situ mapeamento químico de um biofilme vivos por espectrometria de massa de iões secundário de tempo-de-voo (ToF-SIMS). Isto é feito através do cultivo de bactérias tanto fora como dentro do canal SALVI com nossa instalação especializada, bem como através de técnicas de imagem ópticas para detectar a presença de biofilme e espessura antes da análise de ToF-SIMS. Nossos resultados mostram os Picos característicos de biofilme a Shewanella em seu estado natural e hidratado, destacando em seu ambiente de cluster de água localizadas, bem como EPS fragmentos, que são drasticamente diferentes do biofilme a mesma desidratado Estado. Estes resultados demonstram a capacidade de descoberta de SALVI que permite em situ biofilme de imagem com um instrumento de imagem químico baseada em vácuo.

Estes resultados representativos servem para mostrar como o perfil químico do biofilme anexado pode ser identificado e interpretado, como obtidas por ToF-SIMS. Após a plotagem de espectros de massa de aquisição de dados de ToF-SIMS, destacada-se brevemente na seção procedimentos, identificação de pico deve ser conduzida para atribuir as identidades para cada valor de m/z respectivos. Isso pode ser feito através da revisão de literatura extensa na espectrometria de massa em bact?...

Watch this Scientific Journal Video about In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS at JoVE.com

In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

Este artigo apresenta um método para o cultivo de um biofilme para em situ íon secundário de tempo-de-voo espectrometria de massa para mapeamento químico em seu estado hidratado, habilitado por um reator microfluídicos, sistema para análise na Interface líquido do vácuo. A Shewanella oneidensis MR-1 com proteína de fluorescência verde foi usado como um modelo.

In Situ Caracterização de Shewanella oneidensis MR1 biofilmes por SALVI e ToF-SIMS

Bacterial biofilms are surface-associated communities that are vastly studied to understand their self-produced extracellular polymeric substances (EPS) ...

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Research

JoVE Journal

Chemistry

In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

8.9K visualizações.  Pacific Northwest National Laboratory. Este artigo apresenta um método para o cultivo de um biofilme para em situ íon secundário de tempo-de-voo espectrometria de massa para mapeamento químico em seu estado hidratado, habilitado por um reator microfluídicos, sistema para análise na Interface líquido do vácuo. A Shewanella oneidensis MR-1 com proteína de fluorescência verde foi usado como um modelo.

Vídeo: In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of materials that are inaccessible using conventional synthesis techniques. Coupling soft landing with in situ characterization using secondary ion mass spectrometry (SIMS) and infrared reflection absorption spectroscopy (IRRAS) enables analysis of well-defined surfaces under clean vacuum conditions. The capabilities of three soft-landing instruments constructed in our laboratory are illustrated for the representative system of surface-bound organometallics prepared by soft landing of mass-selected ruthenium tris(bipyridine) dications, [Ru(bpy)3]2+ (bpy = bipyridine), onto carboxylic acid terminated self-assembled monolayer surfaces on gold (COOH-SAMs). In situ time-of-flight (TOF)-SIMS provides insight into the reactivity of the soft-landed ions. In addition, the kinetics of charge reduction, neutralization and desorption occurring on the COOH-SAM both during and after ion soft landing are studied using in situ Fourier transform ion cyclotron resonance (FT-ICR)-SIMS measurements. In situ IRRAS experiments provide insight into how the structure of organic ligands surrounding metal centers is perturbed through immobilization of organometallic ions on COOH-SAM surfaces by soft landing. Collectively, the three instruments provide complementary information about the chemical composition, reactivity and structure of well-defined species supported on surfaces.

In Situ SIMS and IR Spectroscopy of Well-defined Surfaces Prepared by Soft Landing of Mass-selected Ions

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of novel materials. Coupled with analysis by in situ secondary ion mass spectrometry (SIMS) and infrared reflection absorption spectroscopy (IRRAS), soft landing provides unprecedented insights into the interactions of well-defined species with surfaces.

In situ SIMS e IR Espectroscopia de Superfícies bem definidos preparados pela Soft Landing de Íons Mass-selecionados

Soft landing of mass-selected ions onto surfaces is a powerful approach for the highly-controlled preparation of materials that are inaccessible using ...

Química

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis

Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended solvent window, low background currents, corrosion resistance, etc., arise from the catalytically inert nature of the surface. However, if during the growth process, non-diamond-carbon (NDC) becomes incorporated into the electrode matrix, the electrochemical properties will change as the surface becomes more catalytically active. As such it is important that the electrochemist is aware of the quality and resulting key electrochemical properties of the BDD electrode prior to use. This paper describes a series of characterization steps, including Raman microscopy, capacitance, solvent window and redox electrochemistry, to ascertain whether the BDD electrode contains negligible NDC i.e. negligible sp2 carbon. One application is highlighted which takes advantage of the catalytically inert and corrosion resistant nature of an NDC-free surface i.e. stable and quantifiable local proton and hydroxide production due to water electrolysis at a BDD electrode. An approach to measuring the local pH change induced by water electrolysis using iridium oxide coated BDD electrodes is also described in detail.

Assessment of Boron Doped Diamond Electrode Quality and Application to In Situ Modification of Local pH by Water Electrolysis

A protocol is described for the characterization of the key electrochemical parameters of a boron doped diamond (BDD) electrode and subsequent application for in situ pH generation experiments.

Avaliação do dopado com boro Diamante Eletrodo de Qualidade e Aplicação de<em&gt; In Situ</em&gt; A modificação de pH local pela eletrólise da água

Boron doped diamond (BDD) electrodes have shown considerable promise as an electrode material where many of their reported properties such as extended ...

Radiolabeling and Quantification of Cellular Levels of Phosphoinositides by High Performance Liquid Chromatography-coupled Flow Scintillation

Phosphoinositides (PtdInsPs) are essential signaling lipids responsible for recruiting specific effectors and conferring organelles with molecular identity and function. Each of the seven PtdInsPs varies in their distribution and abundance, which are tightly regulated by specific kinases and phosphatases. The abundance of PtdInsPs can change abruptly in response to various signaling events or disturbance of the regulatory machinery. To understand how these events lead to changes in the amount of PtdInsPs and their resulting impact, it is important to quantify PtdInsP levels before and after a signaling event or between control and abnormal conditions. However, due to their low abundance and similarity, quantifying the relative amounts of each PtdInsP can be challenging. This article describes a method for quantifying PtdInsP levels by metabolically labeling cells with 3H-myo-inositol, which is incorporated into PtdInsPs. Phospholipids are then precipitated and deacylated. The resulting soluble 3H-glycero-inositides are further extracted, separated by high-performance liquid chromatography (HPLC), and detected by flow scintillation. The labeling and processing of yeast samples is described in detail, as well as the instrumental setup for the HPLC and flow scintillator. Despite losing structural information regarding acyl chain content, this method is sensitive and can be optimized to concurrently quantify all seven PtdInsPs in cells.

Phosphoinositides are signaling lipids whose relative abundance rapidly changes in response to various stimuli. This article describes a method to measure the abundance of phosphoinositides by metabolically labeling cells with 3H-myo-inositol, followed by extraction and deacylation. Extracted glycero-inositides are then separated by high-performance liquid chromatography and quantified by flow scintillation.

Radiomarcação e quantificação dos níveis celulares de Fosfoinositídeos por Cromatografia Líquida de Alta Eficiência acoplado Fluxo de Cintilação

Phosphoinositides (PtdInsPs) are essential signaling lipids responsible for recruiting specific effectors and conferring organelles with molecular ...

In Situ Characterization of Hydrated Proteins in Water by SALVI and ToF-SIMS

This work demonstrates in situ characterization of protein biomolecules in the aqueous solution using the System for Analysis at the Liquid Vacuum Interface (SALVI) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The fibronectin protein film was immobilized on the silicon nitride (SiN) membrane that forms the SALVI detection area. During ToF-SIMS analysis, three modes of analysis were conducted including high spatial resolution mass spectrometry, two-dimensional (2D) imaging, and depth profiling. Mass spectra were acquired in both positive and negative modes. Deionized water was also analyzed as a reference sample. Our results show that the fibronectin film in water has more distinct and stronger water cluster peaks compared to water alone. Characteristic peaks of amino acid fragments are also observable in the hydrated protein ToF-SIMS spectra. These results illustrate that protein molecule adsorption on a surface can be studied dynamically using SALVI and ToF-SIMS in the liquid environment for the first time.

In Situ Characterization of Hydrated Proteins in Water by SALVI and ToF-SIMS

This work presents a protocol for liquid handling and sample introduction to a microchannel for in situ time-of-flight secondary ion mass spectrometry analysis of protein biomolecules in an aqueous solution.

In Situ Caracterização de Proteínas hidratadas em água por SALVI e TOF-SIMS

This work demonstrates in situ characterization of protein biomolecules in the aqueous solution using the System for Analysis at the Liquid Vacuum ...

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

Síntese e Caracterização de Supramoleculares Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

Characterizing Electron Transport through Living Biofilms

Here we demonstrate the method of electrochemical gating used to characterize electrical conductivity of electrode-grown microbial biofilms under physiologically relevant conditions.1 These measurements are performed on living biofilms in aqueous medium using source and drain electrodes patterned on a glass surface in a specialized configuration referred to as an interdigitated electrode (IDA) array. A biofilm is grown that extends across the gap connecting the source and drain. Potentials are applied to the electrodes (ES and ED) generating a source-drain current (ISD) through the biofilm between the electrodes. The dependency of electrical conductivity on gate potential (the average of the source and drain potentials, EG = [ED + ES]/2) is determined by systematically changing the gate potential and measuring the resulting source-drain current. The dependency of conductivity on gate potential provides mechanistic information about the extracellular electron transport process underlying the electrical conductivity of the specific biofilm under investigation. The electrochemical gating measurement method described here is based directly on that used by M. S. Wrighton2,3 and colleagues and R. W. Murray4,5,6 and colleagues in the 1980&#39;s to investigate thin film conductive polymers.

A protocol for measuring electrical conductivity of living microbial biofilms under physiologically relevant conditions is presented.

Caracterizando o transporte de elétrons através de biofilmes vivos

Here we demonstrate the method of electrochemical gating used to characterize electrical conductivity of electrode-grown microbial biofilms under ...

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

In situ imaging and elemental analysis of boehmite (AlOOH) particles in water is realized using the System for Analysis at the Liquid Vacuum Interface (SALVI) and Scanning Electron Microscopy (SEM). This paper describes the method and key steps in integrating the vacuum compatible SAVLI to SEM and obtaining secondary electron (SE) images of particles in liquid in high vacuum. Energy dispersive x-ray spectroscopy (EDX) is used to obtain elemental analysis of particles in liquid and control samples including deionized (DI) water only and an empty channel as well. Synthesized boehmite (AlOOH) particles suspended in liquid are used as a model in the liquid SEM illustration. The results demonstrate that the particles can be imaged in the SE mode with good resolution (i.e., 400 nm). The AlOOH EDX spectrum shows significant signal from the aluminum (Al) when compared with the DI water and the empty channel control. In situ liquid SEM is a powerful technique to study particles in liquid with many exciting applications. This procedure aims to provide technical know-how in order to conduct liquid SEM imaging and EDX analysis using SALVI and to reduce potential pitfalls when using this approach.

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

We present a procedure for real-time imaging and elemental composition analysis of boehmite particles in deionized water by in situ liquid Scanning Electron Microscopy.

In Situ Caracterização de partículas boemita na água usando o líquido SEM

In situ imaging and elemental analysis of boehmite (AlOOH) particles in water is realized using the System for Analysis at the Liquid Vacuum Interface ...

DNA-magnetic Particle Binding Analysis by Dynamic and Electrophoretic Light Scattering

Isolation of DNA using magnetic particles is a field of high importance in biotechnology and molecular biology research. This protocol describes the evaluation of DNA-magnetic particles binding via dynamic light scattering (DLS) and electrophoretic light scattering (ELS). Analysis by DLS provides valuable information on the physicochemical properties of particles including particle size, polydispersity, and zeta potential. The latter describes the surface charge of the particle which plays major role in electrostatic binding of materials such as DNA. Here, a comparative analysis exploits three chemical modifications of nanoparticles and microparticles and their effects on DNA binding and elution. Chemical modifications by branched polyethylenimine, tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane are investigated. Since DNA exhibits a negative charge, it is expected that zeta potential of particle surface will decrease upon binding of DNA. Forming of clusters should also affect particle size. In order to investigate the efficiency of these particles in isolation and elution of DNA, the particles are mixed with DNA in low pH (~6), high ionic strength and dehydration environment. Particles are washed on magnet and then DNA is eluted by Tris-HCl buffer (pH = 8). DNA copy number is estimated using quantitative polymerase chain reaction (PCR). Zeta potential, particle size, polydispersity and quantitative PCR data are evaluated and compared. DLS is an insightful and supporting method of analysis that adds a new perspective to the process of screening of particles for DNA isolation.

This protocol describes the synthesis of magnetic particles and evaluation of their DNA-binding properties via dynamic and electrophoretic light scattering. This method focuses on monitoring changes in particle size, their polydispersity and zeta potential of particle surface which play major role in binding of materials such as DNA.

DNA-magnético partícula análise por dispersão de luz dinâmica e eletroforético de vinculação

Isolation of DNA using magnetic particles is a field of high importance in biotechnology and molecular biology research. This protocol describes the ...

Microfluidic Chips for In Situ Crystal X-ray Diffraction and In Situ Dynamic Light Scattering for Serial Crystallography

This protocol describes fabricating microfluidic devices with low X-ray background optimized for goniometer based fixed target serial crystallography. The devices are patterned from epoxy glue using soft lithography and are suitable for in situ X-ray diffraction experiments at room temperature. The sample wells are lidded on both sides with polymeric polyimide foil windows that allow diffraction data collection with low X-ray background. This fabrication method is undemanding and inexpensive. After the sourcing of a SU-8 master wafer, all fabrication can be completed outside of a cleanroom in a typical research lab environment. The chip design and fabrication protocol utilize capillary valving to microfluidically split an aqueous reaction into defined nanoliter sized droplets. This loading mechanism avoids the sample loss from channel dead-volume and can easily be performed manually without using pumps or other equipment for fluid actuation. We describe how isolated nanoliter sized drops of protein solution can be monitored in situ by dynamic light scattering to control protein crystal nucleation and growth. After suitable crystals are grown, complete X-ray diffraction datasets can be collected using goniometer based in situ fixed target serial X-ray crystallography at room temperature. The protocol provides custom scripts to process diffraction datasets using a suite of software tools to solve and refine the protein crystal structure. This approach avoids the artefacts possibly induced during cryo-preservation or manual crystal handling in conventional crystallography experiments. We present and compare three protein structures that were solved using small crystals with dimensions of approximately 10-20 &#181;m grown in chip. By crystallizing and diffracting in situ, handling and hence mechanical disturbances of fragile crystals is minimized. The protocol details how to fabricate a custom X-ray transparent microfluidic chip suitable for in situ serial crystallography. As almost every crystal can be used for diffraction data collection, these microfluidic chips are a very efficient crystal delivery method.

Microfluidic Chips for In Situ Crystal X-ray Diffraction and In Situ Dynamic Light Scattering for Serial Crystallography

This protocol describes in detail how to fabricate and operate microfluidic devices for X-ray diffraction data collection at room temperature. Additionally, it describes how to monitor protein crystallization by dynamic light scattering and how to process and analyze obtained diffraction data.

Chips microfluídicos por difração de raio x de cristal In Situ e In Situ Difusão dinâmica da luz de cristalografia de Serial

This protocol describes fabricating microfluidic devices with low X-ray background optimized for goniometer based fixed target serial crystallography. The ...

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity and convenient colorimetric readout. However, high densities of nanoparticles are typically needed for detection. The available synthesis-based enhancement protocols are either limited to gold and silver nanoparticles or rely on precise enzymatic control and optimization. Here, we present a protocol to enhance the colorimetric readout of gold, silver, silica, and iron oxide nanoprobes. It was observed that the colorimetric signal can be improved by up to a 10000-fold factor. The basis for such signal enhancement strategies is the chemical reduction of Au3+ to Au0. There are several chemical reactions that enable the reduction of Au3+ to Au0. In the protocol, Good&#39;s buffers and H2O2 are used and it is possible to favor the deposition of Au0 onto the surface of existing nanoprobes, in detriment of the formation of new gold nanoparticles. The protocol consists of the incubation of the microarray with a solution consisting of chloroauric acid and H2O2 in 2-(N-morpholino)ethanesulfonic acid pH 6 buffer following the nanoprobe-based detection assay. The enhancement solution can be applied to paper and glass-based sensors. Moreover, it can be used in commercially available immunoassays as demonstrated by the application of the method to a commercial allergen microarray. The signal development requires less than 5 min of incubation with the enhancement solution and the readout can be assessed by naked eye or low-end image acquisition devices such as a table-top scanner or a digital camera.

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis

In this work, a protocol for signal enhancement of nanoprobe-based biosensing is presented. The protocol is based on the reduction of chloroauric acid onto the surface of existing nanoprobes that consist of gold, silver, silica or iron-oxide nanoparticles.

Sinal de nanossondas rápida realce pela síntese de nanopartículas de ouro em Situ

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity ...