Name: a filter-based surface enhanced raman spectroscopic assay for rapid detection of chemical contaminants
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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. Silver nanodeeltjes Synthesis 15 <ol><li> Los op 18 mg zilvernitraat in 100 ml ultrapuur water (18,2 ΩU) en vortex gedurende 5 sec. </li><li> Los op 27 mg natriumcitraatdihydraat in 1 ml water en vortex gedurende 5 sec. </li><li> Breng alle van de bereide zilvernitraat oplossing voor een conische kolf met een roerstaafje en zet de kolf op een magnetische hete plaat. De kolf onder krachtig roeren met een roersnelheid van 700 opm bij ~ 350 ° C (temperatuur instellen op de plaat). </li><li> Bij het koken,...

<ol>
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Een van de cruciale stappen in dit protocol is de Ag NP synthese, waarbij uniforme Ag NP&#39;s zijn de sleutel voor consistente resultaten. De verwarmingstijd en de concentraties van precursoren moeten nauwkeurig worden geregeld. De gemiddelde grootte van dit preparaat AgNPs is 80 nm, die werd gemeten met de Zetasizer (gegevens niet getoond). Een andere belangrijke stap is het zout aggregatie waar de zoutconcentratie en aggregatie tijd nauwkeurig moeten worden gecontroleerd. Bovendien, de keuze van membraan eveneens bel...

Oppervlakte versterkte Raman spectroscopie (SERS) is een techniek combinatie van Raman spectroscopie met nanotechnologie. De intensiteit van de Raman-verstrooiing van analyten edele metalen nano-oppervlakken sterk door de gelokaliseerde oppervlakte plasmon resonantie. 1 zilvernanodeeltjes (Ag NP) veruit het meest gebruikte SERS substraten vanwege de hoge versterking vermogen. 2 Tot dusver verschillende synthesewerkwijzen van Ag NP ontwikkeld. 3-6 Ag NP kan alleen worden gebruikt als effectieve SERS substraten, of gecombineerd met andere materialen en structuren om de gevoeligheid en / of functionaliteit te verbeteren. 7-11 SERS technieken grote capaciteit voor detectie van verschillende sporenhoeveelheid verontreinigingen in levensmiddelen en milieumonsters aangetoond 12 Traditioneel zijn er twee algemene manieren voor het bereiden van een monster SERS:..-Oplossing op basis en substraat-gebaseerde methoden 13 The -Oplossing op basis method gebruikt NP colloïden te mengen met samples. Dan de NP-analyt-complex wordt verzameld met behulp van centrifugatie, en afgezet op een vaste drager voor Raman meting na droging. Het substraat gebaseerde methode wordt gewoonlijk aangebracht door het afzetten van een aantal microliter monstervloeistof op de geprefabriceerde vast substraat. 14 Geen van deze twee methoden effectief zijn en toepasbaar voor een grote hoeveelheid monstervolume. Verscheidene modificaties van de SERS assays overwon de volumebeperkingen, zoals de integratie van een filtersysteem 15-21 of de opname van een microfluïdische apparaat. 21-24 De gemodificeerde SERS assays grote verbetering in de gevoeligheid en haalbaarheid getoond bewaken van de chemische verontreinigingen in grote watermonsters. Hier laten we gedetailleerd protocol van fabricage en toepassing van een spuitfilter gebaseerd SERS methode sporenhoeveelheid pesticide ferbam en antibioticum ampicilline detecteren.

<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.

De belangrijkste stappen van dit experiment worden getoond in het schema (figuur 1). Figuur 2 blijkt het belang voor de optimale hoeveelheid AgNPs in het membraan bekleding gebruiken om de gevoeligheid te bereiken gemaximaliseerd. 1 ml Ag NP biedt het sterkste signaal bij gebruik ferbam, vergeleken met 0,5 ml (onvoldoende coating) of 2 ml (teveel coating). We konden ferbam op 10 ppb niveau amp...

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

Een werkwijze voor de productie en het uitvoeren van het filter gebaseerde Raman spectroscopische (SERS) assay voor de detectie van chemische verontreinigingen (bijvoorbeeld pesticiden ferbam en antibioticum ampicilline) behandeld.

A-filter op basis Surface Enhanced Raman spectroscopische test voor snelle opsporing van chemische verontreinigingen

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

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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

Een twee-stap pyrolyse-Gas Chromatografie methode met massa spectrometrische detectie voor de identificatie van tatoeage inkt ingrediënten en namaakproducten

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

Preparation of Nanoparticles for ToF-SIMS and XPS Analysis

Voorbereiding van nanodeeltjes voor ToF-SIMS- en XPS-analyse

Nanoparticles have gained increasing attention in recent years due to their potential and application in different fields including medicine, cosmetics, ...