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. argento delle nanoparticelle di sintesi 15 <ol><li> Sciogliere 18 mg di nitrato d&#39;argento in 100 ml di acqua ultrapura (18.2 ΩU) e vortex per 5 sec. </li><li> Sciogliere 27 mg di sodio citrato diidrato in acqua 1 ml e vortex per 5 sec. </li><li> Trasferire tutta la soluzione di nitrato d&#39;argento disposti in una beuta contenente una barra di agitazione e mettere il pallone su una piastra calda magnetica. Riscaldare il pallone sotto agitazione vigorosa con una velocità di agitazione di 700 giri al minuto a ~ 350 ° C (temperatura impostata sulla piastra). </li><li> Quando bolle, aggiungere tutta la soluzione di citrato di sodio preparato nella beuta immediatamente e lasciare la soluzione a bollire per altri 25 min fino a quando la soluzione diventa marrone verdastro, che indica la formazione di Ag NP. </li><li> Togliere il pallone dalla piastra calda e metterlo su un altro piatto magnetico (non riscaldare) e mescolare O / N alla stessa velocità di agitazione a temperatura ambiente fino a quando il composto non raggiunge uno stato stabile, con un colore costante e transparency. Utilizzare uno spettrometro UV-vis per determinare l&#39;assorbimento delle Ag NP preparati, se necessario. </li><li> Diluire la miscela finale con acqua ultrapura a 100 ml. </li><li> Utilizzare un Zetasizer per misurare le dimensioni delle nanoparticelle di Ag, se necessario, secondo il protocollo del produttore. </li><li> Trasferire il colloide Ag in un contenitore sigillato e proteggerlo dalla luce con un foglio di alluminio. Il colloide può essere conservato in frigorifero a 4-7 ° C per 2 mesi, se necessario. </li></ol> 2. Realizzazione di un SERS attivo filtro a membrana <ol><li> Sciogliere 2,92 g di cloruro di sodio (NaCl) in 100 ml di acqua per ottenere una soluzione 50 mM di NaCl. </li><li> Aggiungere 1 ml di soluzione 5 mM NaCl in 1 ml di Ag NP preparati e mescolare su un agitatore oscillante per 10 min a 20 rpm. Questo passo è quello di aggregare le NP Ag in nanoclusters AG. </li><li> Collocare una membrana filtrante (PVDF, 0,1 micron dimensione dei pori) in un portafiltro, che può essere collegato ad una siringa. La membrana dimensione dei pori più piccola era FOund più efficace rispetto alla dimensione dei pori di membrana più grandi (cioè, 0,22 micron) in intrappolamento nanocluster Ag e produrre segnali coerenti. </li><li> Carico 2 ml di nanocluster Ag preparati nella siringa per la filtrazione. Agganciare il portafiltro alla siringa e passare manualmente l&#39;intero volume di nanocluster Ag attraverso la membrana al flusso di 1 goccia / sec. I nanocluster trappole membrana Ag, formando una membrana filtrante SERS-attiva. </li><li> Staccare la membrana del filtro dal supporto del filtro. Particolare cautela è necessaria quando si tiene la membrana sul bordo esterno usando un paio di pinzette per garantire nessun danno alla membrana. Aria secca per circa 3 min e posto membrana su un vetrino. </li><li> rilevamento Raman del substrato SERS <ol><li> Impostare lo strumento Raman di un laser a lunghezza d&#39;onda di 780 nm con una potenza laser di 5 mW, tempo di esposizione di 1 secondo e l&#39;esposizione numero di 2. Impostare l&#39;obiettivo microscopico a 10 volte. Assicurarsi che l&#39;obiettivo del software è impostato di conseguenza troppo. &lt;/ Li&gt; <li> Posizionare il vetrino con la membrana in alto sulla piattaforma dello strumento Raman e utilizzare il microscopio a concentrarsi sulla superficie della membrana. </li><li> Casualmente selezionare 8-10 macchie dalla superficie della membrana e lo strumento raccoglierà automaticamente in sequenza. Aperte dati spettrali nel software del produttore per l&#39;analisi. </li></ol></li></ol> 3. Applicazione della SERS Filtro Attivo sistema di rilevare contaminanti chimici <ol><li> Preparare una soluzione ferbam 10 ppb. Attenzione: Ferbam è altamente volatile. Utilizzare precauzioni (respiratore e occhiali) nel valutare il solido. <ol><li> Pesare 2 mg polvere ferbam e scioglierlo in 20 ml 50% acetonitrile (10 ml di acetonitrile e 10 ml di acqua) per ottenere una soluzione stock (100 ppm). Agitare il pallone per 30 sec. </li><li> Prendere 1 ml di soluzione ferbam 100 ppm in una provetta e aggiungere 9 ml 50% acetonitrile per ottenere una soluzione 10 ppm. Agitare la provetta per 5 secondi. </li><li> Prendere 1 ml di10 ppm soluzione in una provetta e aggiungere 9 ml 50% acetonitrile per ottenere una soluzione 1 ppm. Agitare la provetta per 5 secondi. </li><li> Prendere 1 ml della soluzione di 1 ppm in una provetta e aggiungere 9 ml 50% acetonitrile per ottenere una soluzione di 100 ppb. Agitare la provetta per 5 secondi. </li><li> Prendere 1 ml della soluzione 100 ppb in una provetta e aggiungere 9 ml 50% acetonitrile per ottenere una soluzione 10 ppb. Agitare la provetta per 5 secondi. </li></ol></li><li> Preparare una soluzione ampicillina 1 ppm. <ol><li> Pesare 10 mg polvere ampicillina e sciogliere in 100 ml di acqua per ottenere una soluzione ampicillina 100 ppm. Agitare il pallone per 30 sec. </li><li> Prendere 1 ml della soluzione 100 ppm in una provetta e aggiungere 9 ml di acqua per ottenere una soluzione ampicillina 10 ppm. Agitare la provetta per 5 secondi. </li><li> Prendere 1 ml della soluzione di 10 ppm in una provetta e aggiungere 9 ml di acqua per ottenere una soluzione ampicillina 1 ppm. Agitare la provetta per 5 secondi. </li></ol></li><li> Mettere la membrana del filtro ai portafiltri, con il lato rivestito NP rivolto verso l&#39;alto. &lt;/ Li&gt; <li> Carico 5 ml di un campione in una nuova siringa, e poi attaccarlo al supporto del filtro con una membrana di Ag ricoperto all&#39;interno. </li><li> Far passare manualmente l&#39;intero volume del campione attraverso la membrana al flusso di 1 goccia / sec. molecole bersaglio possono essere assorbiti e concentrati sulle NP adesi alla membrana del filtro. </li><li> Sfilare membrana del filtro dal portafiltro, asciugare all&#39;aria per circa 3 minuti e misurare i segnali utilizzando lo strumento Raman utilizzando lo stesso metodo descritto al punto 2.6. </li><li> Ripetere passaggio 2.2 2.6 preparare un&#39;altra membrana Ag-rivestito, e seguire dal punto 3.3 per il rilevamento degli altri campioni. </li></ol>

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The authors have nothing to disclose.

Uno dei passaggi critici in questo protocollo è la sintesi Ag NP, dove uniformi Ag NP sono la chiave per ottenere risultati coerenti. Il tempo di riscaldamento e le concentrazioni di precursori devono essere controllati con precisione. La dimensione media di questa preparazione AGNPS è di 80 nm, che è stata misurata dal Zetasizer (dati non mostrati). Un altro passo importante è l&#39;aggregazione di sale in cui la concentrazione di sale e tempo di aggregazione devono essere controllati con precisione. Inoltre, la sc...

Surface Enhanced spettroscopia Raman (SERS) è una tecnica che combina spettroscopia Raman con la nanotecnologia. L&#39;intensità di scattering Raman di analiti a nobili metallici nano-superfici è notevolmente migliorata dalla risonanza plasmonica di superficie localizzata. 1 nanoparticelle di argento (Ag NP) sono di gran lunga i SERS più utilizzati substrati grazie alla sua elevata capacità di valorizzazione. 2 Fino ad oggi , sono stati sviluppati diversi metodi di sintesi di Ag NP. 3-6 Ag NP può essere usato da solo come substrati SERS efficaci, o combinati con altri materiali e strutture per migliorare la sensibilità e / o la funzionalità. 7-11 Tecniche SERS hanno dimostrato grande capacità di rilevamento di vari contaminanti quantità in tracce negli alimenti e nei campioni ambientali 12 Tradizionalmente, ci sono due modi comuni per la preparazione di un campione SERS:.. Soluzione-based e metodi di substrato a base 13 Il metho soluzione basata sud utilizza colloidi NP per mescolare con i campioni. Poi il complesso NP-analita viene raccolto mediante centrifugazione, e depositato su un supporto solido per la misurazione Raman dopo l&#39;essiccazione. Il metodo substrato a base di solito è applicata depositando diversi microlitri di campione liquido sul substrato solido prefabbricato. 14 Tuttavia, nessuno di questi due metodi sono efficaci e applicabili per una grande quantità di volume di campione. Diverse modifiche dei dosaggi SERS superato i limiti di volume, come l&#39;integrazione di un sistema di filtri 15-21 o l&#39;incorporazione di un dispositivo microfluidico. 21-24 I saggi SERS modificati hanno mostrato grande miglioramento nella sensibilità e la fattibilità del monitoraggio dei contaminanti chimici in grandi campioni di acqua. Qui mostriamo il protocollo dettagliato di fabbricazione e applicazione di un metodo basato SERS filtro siringa per rilevare quantità traccia di ferbam pesticidi e antibiotici ampicillina.

<table><tbody><tr><td>Ampicillin</td><td>Fisher Scientific</td><td>BP1760-5</td><td>N/A</td></tr><tr><td>Ferbam</td><td>Chem Service</td><td>N-11970-250MG</td><td>98+%</td></tr><tr><td>Silver nitrate</td><td>Sigma Aldrich</td><td>209139</td><td>99.0+%</td></tr><tr><td>Sodium citrate dehydrate</td><td>Sigma Aldrich</td><td>W302600</td><td>99+%</td></tr><tr><td>Sodium chloride</td><td>Sigma Aldrich</td><td>S7653</td><td>99.5+%</td></tr><tr><td>EMD Millipore Durapore PVDF Membrane Filters</td><td>Fisher Scientific</td><td>VVLP01300</td><td>0.10 &amp;micro;m Pore Size, hydrophilic</td></tr><tr><td>Polycarbonate Filter Holders</td><td>Cole-Parmer</td><td>EW-29550-40</td><td>13 mm diameter</td></tr><tr><td>Analog Vortex Mixer</td><td>Fisher Scientific</td><td>02-215-365</td><td>N/A</td></tr><tr><td>Nutating Mixers</td><td>Fisher Scientific</td><td>05-450-213</td><td>N/A</td></tr><tr><td>DXR Raman spectroscope</td><td>Thermo Scientific</td><td>IQLAADGABFFAHCMAPB</td><td>Laser power: 1 mW&lt;br /&gt; Exposure time: 5 sec</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.

Le fasi principali di questo esperimento sono stati mostrati nel diagramma schematico (Figura 1). La Figura 2 ha dimostrato l&#39;importanza di usare il volume ottimizzata AGNPS nel rivestimento della membrana al fine di ottenere sensibilità massimizzato. 1 ml di Ag NP fornisce il segnale più forte quando si utilizza ferbam, rispetto a 0,5 ml (rivestimento insufficiente) o 2 ml (troppo rivestimento). <p class="jove_content" fo:keep...

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

Procedimento per la fabbricazione ed eseguendo la superficie filtro Enhanced Raman spettroscopiche (SERS) Test per l&#39;individuazione dei contaminanti chimici (cioè, ferbam pesticidi e ampicillina) è presentata.

Una Superficie-filtro basato avanzata Raman spettroscopica Assay per Rapid individuazione dei contaminanti chimici

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

Universidad de Cartagena UDEC

Research

JoVE Journal

Chemistry

9.3K Views.  University of Massachusetts Amherst.  Procedimento per la fabbricazione ed eseguendo la superficie filtro Enhanced Raman spettroscopiche (SERS) Test per l'individuazione dei contaminanti chimici (cioè, ferbam pesticidi e ampicillina) è presentata. 

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

Fabricating a UV-Vis and Raman Spectroscopy Immunoassay Platform

Immunoassays are used to detect proteins based on the presence of associated antibodies. Because of their extensive use in research and clinical settings, a large infrastructure of immunoassay instruments and materials can be found. For example, 96- and 384-well polystyrene plates are available commercially and have a standard design to accommodate ultraviolet-visible (UV-Vis) spectroscopy machines from various manufacturers. In addition, a wide variety of immunoglobulins, detection tags, and blocking agents for customized immunoassay designs such as enzyme-linked immunosorbent assays (ELISA) are available.
Despite the existing infrastructure, standard ELISA kits do not meet all research needs, requiring individualized immunoassay development, which can be expensive and time-consuming. For example, ELISA kits have low multiplexing (detection of more than one analyte at a time) capabilities as they usually depend on fluorescence or colorimetric methods for detection. Colorimetric and fluorescent-based analyses have limited multiplexing capabilities due to broad spectral peaks. In contrast, Raman spectroscopy-based methods have a much greater capability for multiplexing due to narrow emission peaks. Another advantage of Raman spectroscopy is that Raman reporters experience significantly less photobleaching than fluorescent tags1. Despite the advantages that Raman reporters have over fluorescent and colorimetric tags, protocols to fabricate Raman-based immunoassays are limited. The purpose of this paper is to provide a protocol to prepare functionalized probes to use in conjunction with polystyrene plates for direct detection of analytes by UV-Vis analysis and Raman spectroscopy. This protocol will allow researchers to take a do-it-yourself approach for future multi-analyte detection while capitalizing on pre-established infrastructure.

Nanoparticle-based optical probes have been designed as a vehicle for detecting antigens using Raman and UV-Vis spectroscopy. Here we describe a protocol for preparing such probes for a UV-Vis/Raman spectroscopy immunoassay in such a way to incorporate future multiplexing capabilities.

Realizzazione di un UV-Vis e Raman Spectroscopy Immunoassay Platform

Immunoassays are used to detect proteins based on the presence of associated antibodies. Because of their extensive use in research and clinical settings, ...

Ricerca

Biochimica

Surface Enhanced Raman Spectroscopy Detection of Biomolecules Using EBL Fabricated Nanostructured Substrates

Fabrication and characterization of conjugate nano-biological systems interfacing metallic nanostructures on solid supports with immobilized biomolecules is reported. The entire sequence of relevant experimental steps is described, involving the fabrication of nanostructured substrates using electron beam lithography, immobilization of biomolecules on the substrates, and their characterization utilizing surface-enhanced Raman spectroscopy (SERS). Three different designs of nano-biological systems are employed, including protein A, glucose binding protein, and a dopamine binding DNA aptamer. In the latter two cases, the binding of respective ligands, D-glucose and dopamine, is also included. The three kinds of biomolecules are immobilized on nanostructured substrates by different methods, and the results of SERS imaging are reported. The capabilities of SERS to detect vibrational modes from surface-immobilized proteins, as well as to capture the protein-ligand and aptamer-ligand binding are demonstrated. The results also illustrate the influence of the surface nanostructure geometry, biomolecules immobilization strategy, Raman activity of the molecules and presence or absence of the ligand binding on the SERS spectra acquired.

We describe the fabrication and characterization of nano-biological systems interfacing nanostructured substrates with immobilized proteins and aptamers. The relevant experimental steps involving lithographic fabrication of nanostructured substrates, bio-functionalization, and surface-enhanced Raman spectroscopy (SERS) characterization, are reported. SERS detection of surface-immobilized proteins, and probing of protein-ligand and aptamer-ligand binding is demonstrated.

Surface Enhanced Raman Spectroscopy Rilevamento di Biomolecole Utilizzando EBL manufatti nanostrutturati Substrati

Fabrication and characterization of conjugate nano-biological systems interfacing metallic nanostructures on solid supports with immobilized biomolecules ...

Ingegneria

Rapid High-throughput Species Identification of Botanical Material Using Direct Analysis in Real Time High Resolution Mass Spectrometry

We demonstrate that direct analysis in real time-high resolution mass spectrometry can be used to produce mass spectral profiles of botanical material, and that these chemical fingerprints can be used for plant species identification. The mass spectral data can be acquired rapidly and in a high throughput manner without the need for sample extraction, derivatization or pH adjustment steps. The use of this technique bypasses challenges presented by more conventional techniques including lengthy chromatography analysis times and resource intensive methods. The high throughput capabilities of the direct analysis in real time-high resolution mass spectrometry protocol, coupled with multivariate statistical analysis processing of the data, provide not only class characterization of plants, but also yield species and varietal information. Here, the technique is demonstrated with two psychoactive plant products, Mitragyna speciosa (Kratom) and Datura (Jimsonweed), which were subjected to direct analysis in real time-high resolution mass spectrometry followed by statistical analysis processing of the mass spectral data. The application of these tools in tandem enabled the plant materials to be rapidly identified at the level of variety and species.

A method for species identification of botanical material by direct analysis in real time-high resolution mass spectrometry and multivariate statistical analysis is presented.

Rapid high-throughput Specie Identificazione del materiale botanico Utilizzando l&#39;analisi diretta in tempo reale ad alta risoluzione Spettrometria di Massa

We demonstrate that direct analysis in real time-high resolution mass spectrometry can be used to produce mass spectral profiles of botanical material, ...

Chimica

Preparation and Application of a New Bacterial Biosensor for the Presumptive Detection of Gunshot Residue

MicRoboCop is a biosensor that has been designed for a unique application in forensic chemistry. MicRoboCop is a system made up of three devices that, when used together, can indicate the presence of gunshot residue (GSR) by producing a fluorescence signal in the presence of three key analytes (antimony, lead, and organic components of GSR). The protocol describes the synthesis of the biosensors using Escherichia coli (E. coli), and the analytical chemistry methods used to evaluate the selectivity and sensitivity of the sensors. The functioning of the system is demonstrated by using GSR collected from the inside of a spent cartridge casing. Once prepared, the biosensors can be stored until needed and can be used as a test for these key analytes. A positive response from all three analytes provides a presumptive positive test for GSR, while each individual device has applications for detecting the analytes in other samples (e.g., a detector for lead contamination in drinking water). The main limitation of the system is the time required for a positive signal; future work may involve studying different organisms to optimize the response time.

A protocol is presented using synthetic biology techniques to synthesize a set of bacterial biosensors for the analysis of gunshot residue, and to test the functioning of the devices for their intended use using fluorescence spectroscopy.

Preparazione e applicazione di un nuovo biosensore batterico per il rilevamento presuntivo di residui di arma da fuoco

MicRoboCop is a biosensor that has been designed for a unique application in forensic chemistry. MicRoboCop is a system made up of three devices that, ...

Multiplex Chemical Imaging Based on Broadband Stimulated Raman Scattering Microscopy

Stimulated Raman scattering (SRS) microscopy is a nonlinear optical technique for label-free chemical imaging. This analytical tool delivers chemical maps at high speed, and high spatial resolution of thin samples by directly interrogating their molecular vibrations. In its standard implementation, SRS microscopy is narrowband and forms images with only a single vibrational frequency at a time. However, this approach not only hinders the chemical specificity of SRS but also neglects the wealth of information encoded within vibrational spectra. 
These limitations can be overcome by broadband SRS, an implementation capable of extracting a vibrational spectrum per pixel of the image in parallel. This delivers hyperspectral data that, when coupled with chemometric analysis, maximizes the amount of information retrieved from the specimen. Thus, broadband SRS improves the chemical specificity of the system, allowing the quantitative determination of the concentration of the different constituents of a sample. Here, we report a protocol for chemical imaging with broadband SRS microscopy, based on a home-built SRS microscope operating with a custom differential multichannel-lock-in amplifier detection. It discusses the sample preparation, alignment of the SRS apparatus, and chemometric analysis. By acquiring vibrational Raman spectra, the protocol illustrates how to identify different chemical species within a mixture, determining their relative concentrations.

We present a protocol to acquire chemical images with broadband stimulated Raman scattering (SRS) microscopy. Based on an SRS microscope that operates with differential multichannel-lock-in detection, the protocol describes the sample preparation, adjustment of the SRS apparatus, and chemometrics to disentangle different constituents of chemically heterogeneous samples.

Imaging chimico multiplex basato sulla microscopia a dispersione Raman stimolata a banda larga

Stimulated Raman scattering (SRS) microscopy is a nonlinear optical technique for label-free chemical imaging. This analytical tool delivers chemical maps ...

Direct Comparison of Hyperspectral Stimulated Raman Scattering and Coherent Anti-Stokes Raman Scattering Microscopy for Chemical Imaging

Stimulated Raman scattering (SRS) and coherent anti-Stokes Raman scattering (CARS) microscopy are the most widely used coherent Raman scattering imaging technologies. Hyperspectral SRS and CARS imaging offer Raman spectral information at every pixel, which enables better separation of different chemical compositions. Although both techniques require two excitation lasers, their signal detection schemes and spectral properties are quite different. The goal of this protocol is to perform both hyperspectral SRS and CARS imaging on a single platform and compare the two microscopy techniques for imaging different biological samples. The spectral focusing method is employed to acquire spectral information using femtosecond lasers. By using standard chemical samples, the sensitivity, spatial resolution, and spectral resolution of SRS and CARS in the same excitation conditions (i.e., power at the sample, pixel dwell time, objective lens, pulse energy) are compared. The imaging contrasts of CARS and SRS for biological samples are juxtaposed and compared. The direct comparison of CARS and SRS performances would allow for optimal selection of the modality for chemical imaging.

This paper directly compares the resolution, sensitivity, and imaging contrasts of stimulated Raman scattering (SRS) and coherent anti-Stokes Raman scattering (CARS) integrated into the same microscope platform. The results show that CARS has a better spatial resolution, SRS gives better contrasts and spectral resolution, and both methods have similar sensitivity.

Confronto diretto tra lo scattering Raman stimolato iperspettrale e la microscopia a dispersione raman coerente anti-Stokes per l'imaging chimico

Stimulated Raman scattering (SRS) and coherent anti-Stokes Raman scattering (CARS) microscopy are the most widely used coherent Raman scattering imaging ...

Sintesi di nanoparticelle e nanostrutture tramite ablazione laser

Ultrafast Laser-Ablated Nanoparticles and Nanostructures for Surface-Enhanced Raman Scattering-Based Sensing Applications

The technique of ultrafast laser ablation in liquids has evolved and matured over the past decade, with several impending applications in various fields such as sensing, catalysis, and medicine. The exceptional feature of this technique is the formation of nanoparticles (colloids) and nanostructures (solids) in a single experiment with ultrashort laser pulses. We have been working on this technique for the past few years, investigating its potential using the surface-enhanced Raman scattering (SERS) technique in hazardous materials sensing applications. Ultrafast laser-ablated substrates (solids and colloids) could detect several analyte molecules at the trace levels/mixture form, including dyes, explosives, pesticides, and biomolecules. Here, we present some of the results achieved using the targets of Ag, Au, Ag-Au, and Si. We have optimized the nanostructures (NSs) and nanoparticles (NPs) obtained (in liquids and air) using different pulse durations, wavelengths, energies, pulse shapes, and writing geometries. Thus, various NSs and NPs were tested for their efficiency in sensing numerous analyte molecules using a simple, portable Raman spectrometer. This methodology, once optimized, paves the way for on-field sensing applications. We discuss the protocols in (a) synthesizing the NPs/NSs via laser ablation, (b) characterization of NPs/NSs, and (c) their utilization in the SERS-based sensing studies.

Autore in primo piano: Progressi e applicazioni nella sintesi di nanoparticelle attraverso l'ablazione laser nei liquidi 

Ultrafast laser ablation in liquid is a precise and versatile technique for synthesizing nanomaterials (nanoparticles [NPs] and nanostructures [NSs]) in liquid/air environments. The laser-ablated nanomaterials can be functionalized with Raman-active molecules to enhance the Raman signal of analytes placed on or near the NSs/NPs.

Nanoparticelle e nanostrutture ultraveloci ad ablazione laser per applicazioni di rilevamento basate sullo scattering Raman potenziato dalla superficie

The technique of ultrafast laser ablation in liquids has evolved and matured over the past decade, with several impending applications in various fields ...

Fabbricazione di substrato flessibile per la rilevazione SERS di R6G e Thiram

Fabrication of polydimethylsiloxane (PDMS)-Based Flexible Surface-Enhanced Raman Scattering (SERS) Substrate for Ultrasensitive Detection

This article presents a fabrication method for a flexible substrate designed for Surface-Enhanced Raman Scattering (SERS). Silver nanoparticles (AgNPs) were synthesized through a complexation reaction involving silver nitrate (AgNO3) and ammonia, followed by reduction using glucose. The resulting AgNPs exhibited a uniform size distribution ranging from 20 nm to 50 nm. Subsequently, 3-aminopropyl triethoxysilane (APTES) was employed to modify a PDMS substrate that had been surface-treated with oxygen plasma. This process facilitated the self-assembly of AgNPs onto the substrate. A systematic evaluation of the impact of various experimental conditions on substrate performance led to the development of a SERS substrate with excellent performance and an Enhanced Factor (EF). Utilizing this substrate, impressive detection limits of 10-10 M for R6G (Rhodamine 6G) and 10-8 M for Thiram were achieved. The substrate was successfully employed for detecting pesticide residues on apples, yielding highly satisfactory results. The flexible SERS substrate demonstrates great potential for real-world applications, including detection in complex scenarios.

Autore in primo piano: Sviluppo e applicazione di substrati flessibili SERS utilizzando AgNP sintetizzati 

This protocol describes a fabrication method for a flexible substrate for surface-enhanced Raman scattering. This method has been used in the successful detection of low concentrations of R6G and Thiram.

Fabbricazione di substrato SERS (Flexible Surface-Enhanced Raman Scattering) a base di polidimetilsilossano (PDMS) per la rilevazione ultrasensibile

This article presents a fabrication method for a flexible substrate designed for Surface-Enhanced Raman Scattering (SERS). Silver nanoparticles (AgNPs) ...

Una Superficie-filtro basato avanzata Raman spettroscopica Assay per Rapid individuazione dei contaminanti chimici

Riepilogo

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Capitoli in questo video

Realizzazione di un UV-Vis e Raman Spectroscopy Immunoassay Platform

Surface Enhanced Raman Spectroscopy Rilevamento di Biomolecole Utilizzando EBL manufatti nanostrutturati Substrati

Rapid high-throughput Specie Identificazione del materiale botanico Utilizzando l'analisi diretta in tempo reale ad alta risoluzione Spettrometria di Massa

Preparazione e applicazione di un nuovo biosensore batterico per il rilevamento presuntivo di residui di arma da fuoco

Imaging chimico multiplex basato sulla microscopia a dispersione Raman stimolata a banda larga

Confronto diretto tra lo scattering Raman stimolato iperspettrale e la microscopia a dispersione raman coerente anti-Stokes per l'imaging chimico

Nanoparticelle e nanostrutture ultraveloci ad ablazione laser per applicazioni di rilevamento basate sullo scattering Raman potenziato dalla superficie

Nanoparticelle e nanostrutture ultraveloci ad ablazione laser per applicazioni di rilevamento basate sullo scattering Raman potenziato dalla superficie

Nanoparticelle e nanostrutture ultraveloci ad ablazione laser per applicazioni di rilevamento basate sullo scattering Raman potenziato dalla superficie

Fabbricazione di substrato SERS (Flexible Surface-Enhanced Raman Scattering) a base di polidimetilsilossano (PDMS) per la rilevazione ultrasensibile