Name: visible-light induced reduction of graphene oxide using plasmonic nanoparticle
Uploaded: 2015-09-22T16:00:00.000+00:00
Duration: 7 min 24 s
Description: Watch this Scientific Journal Video about Visible-light Induced Reduction of Graphene Oxide Using Plasmonic Nanoparticle at JoVE.com

Diese Arbeit wurde von der National Research Foundation of Korea (2013R1A1A1061387) und KU-KIST Forschungsfonds unterstützt.

1. Herstellung der Vorstufe <ol><li> Herstellung von Graphenoxid (GO): <ol><li> GO Vorbereitung mit modifizierten Hummer-Methode 14 <ol><li> Hinzufügen von 3,0 g Graphitflocken zu einer Mischung aus konzentrierter H 2 SO 4 / H 3 PO 4 (360: 40 ml) bei RT. (Hinweis: Besondere Sorgfalt muss bei der Verwendung von starken Säuren H 2 SO 4 und H 3 PO 4 entnommen werden.) </li><li> Hinzufügen KMnO 4 (18,0 g) langsam unter Rühren und Kühlen in einem Eisbad, um die Temperatur des Reaktionsgemisches auf &lt;35 ° C zu halten. (Die klebrig mit erhöhter Reaktionszeit-Lösung benötigen, um die ordnungsgemäße Methode verwenden, um ein effizientes Rühren aufrecht zu erhalten.) (Hinweis: Besondere Sorgfalt muss genommen werden, während es KMnO 4 aufgrund der exothermen Reaktion.) </li><li> Rühre 12 Stunden bei 50 ° C und dann auf RT abkühlen und gießt Reaktionsgemisch auf Eis (400 ml), das 30% H 2 O 2 (3 ml). </li><li> Filtern Sie die reAction Mischung unter Verwendung einer Metall US Standardtest Sieb (300 um), um nicht umgesetzte Graphit und Zentrifuge das Filtrat (4722 xg Geschwindigkeit für 2 Stunden) zu entfernen, um den Überstand zu entfernen. </li><li> Wiederholen Zentrifugationsschritt mit 200 ml Wasser, 200 ml 30% HCl, 200 ml Ethanol und destilliertem Wasser wieder bis zu einem pH von 5,0-6,0 zu erreichen Lösung bei. </li><li> Lyophilisieren die endgültigen Lösungen für einen flauschigen GO Pulver herzustellen. </li><li> Um Nano GO-Lösung herzustellen, in 40 ml dreifach destilliert Wasser (&gt; 18 M &amp; Omega;) aufzulösen 20 mg GO-Pulver und dann bei längerer Ultraschallbehandlung (35% Amplitude, 500 W, 2 h), Peeling, bis der gesamte Größenverteilung werden unter 150 nm, dann zentrifugieren es zweimal (10.625 xg Geschwindigkeit, 15 min), um Niederschläge zu (un-abgeblätterten großen GO Blätter) zu entfernen. </li></ol></li></ol></li><li> Vorbereitung plasmonischer Nanopartikel <ol><li> Herstellung von AuNPs <ol><li> Citrat-stabilisierten Kugelform Gold-Nanopartikel (AuNPs, OD = 1,0) von 30 nm Partikelgröße wurde für r-GO Reduktion verwendet. </li></ol></li><li> Herstellung von AuNRs 15 <ol><li> Vorbereitung der Keimlösung durch Zugabe einer frisch hergestellten 0,6 ml eiskalten Lösung von NaBH &amp; sub4; -Lösung (0,01 M) in eine wässrige Mischlösung compose von 0,25 ml HAuCl 4 (0,01 M) und 9,75 ml Cetyltrimethylammoniumbromid (CTAB, 0,1 M ). </li><li> Die resultierende Mischung kräftig für 0,5 min und dann halten Sie es bei 28 ° C für 3 Stunden. </li><li> Vorbereitung der Wachstumslösung durch Vermischen von 475 ml CTAB (0,1 M) wurden 3 ml AgNO 3 (0,01 M) und 20 ml HAuCl 4 (0,01 M). </li><li> Dann frisch hergestellten 3,2 ml Ascorbinsäure (0,01 M) zu der Mischung, gefolgt von der Zugabe von 0,8 ml einer wässrigen HCl (1,0 M) Lösung zuzugeben. </li><li> Im letzten Schritt hinzuzufügen 3,2 ml Keimlösung zu der Wachstumslösung bei 28 ° C und unterziehen das Reaktionsgemisch auf eine schnelle Inversion für ein paar Sekunden. Schließlich keep der resultierenden Mischung ungestört für mindestens 6 Stunden. </li><li> Analyse der hergestellten AuNRs mit UV-Vis-Spektroskopie zur Absorptionsmaxima (λ max) und TEM-Analyse (typischerweise die λ max und dem Seitenverhältnis wurde gefunden, 730 nm bzw. 3,5 sein). </li></ol></li><li> Herstellung von AuNSs 16 <ol><li> Vorbereitung einer wässrigen Stammlösung von 4- (2-Hydroxyethyl) -1-piperazinethansulfonsäure (HEPES) mit einer Konzentration von 100 mM und der pH auf 7,4 bei 25ºC einstellen durch Zugabe von 1,0 M NaOH-Lösung. </li><li> Mix 20 ml Phosphatpuffer (100 mM) mit 30 ml 2- [4- (2-Hydroxyethyl) -1-piperazinyl] ethansulfonsäure (100 mM). </li><li> Dann fügen Sie 500 ul von Gold (III) -chlorid-Trihydrat (20 mM) zu der obigen Mischung und hält bei 28,5 ° C für 30 min im Wasserbad. Lösung Farbe von hellgelb bis grünlich-blau nach 30 Minuten beobachtet werden. </li><li> Zentrifugieren Sie die Lösung bei 8928 xg Geschwindigkeit für 30 Minuten und zu dispergierendie Präzipitate in destilliertem Wasser. </li><li> Schließlich analysiert man die vorbereitete AuNSs mit UV-Vis-Spektroskopie zur Absorptionsmaxima (λ max) und TEM-Analyse für Teilchengröße Bestätigung ein, der 740 nm und 30 nm betragen. </li></ol></li></ol></li></ol> 2. Herstellung von r-GO mit sichtbarem Licht und AuNPs <ol><li> 1 ml plasmonic Nanopartikel (Abs 1,0 bei 520 nm für AuNPs, Abs 1,0 bei 750 nm für AuNRs und ABS-1,0 bei 730 nm für AuNSs bezeichnet), und 100 ul von Ammoniumhydroxid (28%, w / v%) und 10 ml der GO-Lösung (OD 1,0 bei 230 nm, 0,125 mg ml -1) in einem Pyrex-Glasreaktor mit einem Wasserzirkulationsmantel ausgestattet war. </li><li> Bestrahlen der Mischung mit Xe-Lampe (Leistungsdichte von 1,56 W cm -2) für 30 Minuten mit Wasserumlauf durch die Wasserzirkulationsmantel um die Temperatur auf 25 ° C zu halten und dann zu zentrifugieren die Lösung bei 10.625 xg Geschwindigkeit für 15 minentfernen Gold-Nanopartikeln. </li><li> Nehmen Sie den Überstand, der die vorbereitet r-GO, um mit UV-Vis-Spektralphotometer Analyse im Bereich von 200 bis 900 nm (r-GO sollte die Unterscheidungsabsorptionsbande bei 270 nm zeigen). </li></ol> 3. Ziel-DNA-Nachweis unter Verwendung von R-GO-Lösung 17 <ol><li> Für Fluoreszenzlöschung, fügen Sie 20 ul 10 -6 M Cy3-modifizierte ssDNA (5&#39;-ATC CTT ATC AAT ATT TAA CAA TAA TCC CTC-Cy3-3 &#39;) in GO oder r-GO Lösung, die 25 &amp; mgr; l GO (0,125 mg ml -1) oder r-GO (0,125 mg ml -1) in 1.955 &amp; mgr; l von 0,3 M PBS-Lösung (10 mM Phosphatpuffer, 0,3 M NaCl) und Inkubation für 10 min bei RT. </li><li> Messung der Fluoreszenzintensität der Proben mit Spektralfluorometer (λ ex = 529 nm). </li><li> Zur Zielerkennung, fügen Sie 200 ul der Target-Oligonukleotid-Lösung (5&#39;-GAG GGA TTA TTA TTG AAT ATT GAT AAG GAT-3 &#39;) in drei verschiedenen Konzentrationen (10 -6 &lt;/ sup&gt; M, 10 -7 M, 10 -8 M) in den GO oder r-GO-Lösung, enthaltend 20 ul 10 -6 M ssDNA-Cy3, 25 ul GO oder r-GO (0,125 mg ml -1) und 1755 &amp; mgr; l von 0,3 M PBS für die Fluoreszenz-Recovery-Experiment. 17 Hinweise: Lichtquellen &amp; Reactor Sichtbares Licht (400-780 nm) Quelle. Sichtbares Licht zu bestrahlen durch Pyrex-Glasreaktor (Fensterdurchmesser = 1,1 cm), die GO-Lösung mit Xe-Lampe (1,56 W / cm 2 Leistung). Die Photonenenergie an den Reaktor angelegt wird berechnet, um 4,8 × 10 21 Photonen pro min (2A-2C) sein. Nah-Infrarot (NIR) Laser. NIR-Laser (Fensterdurchmesser = 13,2 cm) mit Leistungsdichte von 0,36 W / cm 2, und die Betriebswellenlänge von 808 nm als Quelle für nahes Infrarotlicht für GO Reduktionsreaktionen (2E) verwendet wurde. Die Photonenenergie wird berechnet, um 2,43 × 10 21 Photonen pro min betragen. Reactor: Pyrex-Glasreaktor (Fensterdurchmesser = 1,1 cm; Reaktionsvolumen = 10 ml) mit einem Wasserumlauf Mantel ausgestattet ist sowohl für sichtbares Licht und NIR-Licht bestrahlt verwendet GO Reduktionsreaktionen (2F). </li></ol>

<ol>
	<li>Novoselov, K. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electric+Field+Effect+in+Atomically+Thin+Carbon+Films.">Electric Field Effect in Atomically Thin Carbon Films.</a> Science. 306 (5696), 666-669 (2004).</li><li>Obraztsov, A. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+Vapour+Deposition+Making+Graphene+on+a+Large+Scale.">Chemical Vapour Deposition Making Graphene on a Large Scale.</a> Nat Nanotechnol. 4 (4), 212-213 (2009).</li><li>Choi, W., Lahiri, I., Seelaboyina, R., Kang, Y. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+of+Graphene+and+Its+Applications+A+Review.">Synthesis of Graphene and Its Applications A Review.</a> Crit Rev Solid State Mater Sci. 35 (1), 52-71 (2010).</li><li>Zhou, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microstructuring+of+Graphene+Oxide+Nanosheets+Using+Direct+Laser+Writing.">Microstructuring of Graphene Oxide Nanosheets Using Direct Laser Writing.</a> Adv Mater. 22 (1), 67-71 (2010).</li><li>Stankovich, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Graphene+Based+Composite+Materials.">Graphene Based Composite Materials.</a> Nature. 442 (7100), 282-286 (2006).</li><li>Becerril, H. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+Solution-Processed+Reduced+Graphene+Oxide+Films+as+Transparent+Conductors.">Evaluation of Solution-Processed Reduced Graphene Oxide Films as Transparent Conductors.</a> ACS Nano. 2 (3), 463-470 (2008).</li><li>Wang, X., Zhi, L., M&#252;llen, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transparent+Conductive+Graphene+Electrodes+for+Dye+Sensitized+Solar+Cells.">Transparent Conductive Graphene Electrodes for Dye Sensitized Solar Cells.</a> Nano Lett. 8 (1), 323-327 (2007).</li><li>Sungjin, P., Ruoff, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+Methods+for+the+Production+of+Graphenes.">Chemical Methods for the Production of Graphenes.</a> Nat Nanotechnol. 4 (4), 217-224 (2009).</li><li>Akhavan, O., Ghaderi, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photocatalytic+Reduction+of+Graphene+Oxide+Nanosheets+on+TiO2+Thin+Film+for+Photoinactivation+of+Bacteria+in+Solar+Light+Irradiation.">Photocatalytic Reduction of Graphene Oxide Nanosheets on TiO2 Thin Film for Photoinactivation of Bacteria in Solar Light Irradiation.</a> J Phys Chem C. 113 (47), 20214-20220 (2009).</li><li>Huang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pulsed+Laser+Assisted+Reduction+of+Graphene+Oxide.">Pulsed Laser Assisted Reduction of Graphene Oxide.</a> Carbon. 49 (7), 2431-2436 (2011).</li><li>Cote, L. J., Cruz-Silva, R., Huang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flash+Reduction+and+Patterning+of+Graphite+Oxide+and+Its+Polymer.">Flash Reduction and Patterning of Graphite Oxide and Its Polymer.</a> Composite. J. Am. Chem. Soc. 131 (31), 11027-11032 (2009).</li><li>Wu, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+plasmon+resonance-induced+visible+light+photocatalytic+reduction+of+graphene+oxide:+Using+Ag+nanoparticles+as+a+plasmonic+photocatalyst.">Surface plasmon resonance-induced visible light photocatalytic reduction of graphene oxide: Using Ag nanoparticles as a plasmonic photocatalyst.</a> Nanoscale. 3 (5), 2142-2144 (2011).</li><li>Kumar, D., Kaur, S., Lim, D. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Plasmon-assisted+and+visible-light+induced+graphene+oxide+reduction+and+efficient+fluorescence+quenching.">Plasmon-assisted and visible-light induced graphene oxide reduction and efficient fluorescence quenching.</a> Chem. Commun. 50 (88), 13481-13484 (2014).</li><li>Gilje, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photothermal+Deoxygenation+of+Graphene+Oxide+for+Patterning+and+Distributed+Ignition+Applications.">Photothermal Deoxygenation of Graphene Oxide for Patterning and Distributed Ignition Applications.</a> Adv. Mater. 22 (3), 419-423 (2010).</li><li>Cote, L. J., Kim, F., Huang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Langmuir&#8722;Blodgett+Assembly+of+Graphite+Oxide+Single+Layers.">Langmuir&#8722;Blodgett Assembly of Graphite Oxide Single Layers.</a> J. Am. Chem. Soc. 131 (3), 1043-1049 (2008).</li><li>Ming, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+Evidence+of+Plasmophores:+Plasmon-Directed+Polarized+Emission+from+Gold+Nanorod&#8211;Fluorophore+Hybrid+Nanostructures.">Experimental Evidence of Plasmophores: Plasmon-Directed Polarized Emission from Gold Nanorod&#8211;Fluorophore Hybrid Nanostructures.</a> Nano Lett. 11 (6), 2296-2303 (2011).</li><li>Xie, J., Lee, J. Y., Seedless Wang, D. I. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surfactantless,+High-Yield+Synthesis+of+Branched+Gold+Nanocrystals+in+HEPES+Buffer+Solution.">Surfactantless, High-Yield Synthesis of Branched Gold Nanocrystals in HEPES Buffer Solution.</a> Chem. Mater. 19 (11), 2823-2830 (2007).</li><li>Ferrari, A. C., Robertson, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resonant+Raman+spectroscopy+of+disordered,+amorphous,+and+diamond+like+carbon.">Resonant Raman spectroscopy of disordered, amorphous, and diamond like carbon.</a> Phys. Rev. B. 64 (7), 075414-1-075414-13 (2000).</li><li>Tian, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One&#8211;pot+green+hydrothermal+synthesis+of+CuO&#8211;Cu2O&#8211;Cu+nanorod&#8211;decorated+reduced+graphene+oxide+composites+and+their+application+in+photocurrent+generation.">One&#8211;pot green hydrothermal synthesis of CuO&#8211;Cu2O&#8211;Cu nanorod&#8211;decorated reduced graphene oxide composites and their application in photocurrent generation.</a> Catal. Sci. Technol. 2 (11), 2227-2230 (2012).</li><li>Liu, S., Tian, J., Wang, L., Sun, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+for+the+production+of+reduced+graphene+oxide+using+benzylamine+as+a+reducing+and+stabilizing+agent+and+its+subsequent+decoration+with+Ag+nanoparticles+for+enzymeless+hydrogen+peroxide+detection.">A method for the production of reduced graphene oxide using benzylamine as a reducing and stabilizing agent and its subsequent decoration with Ag nanoparticles for enzymeless hydrogen peroxide detection.</a> CARBON. 49 (10), 3158-3164 (2011).</li><li>Tian, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Environmentally+Friendly,+One&#8211;Pot+Synthesis+of+Ag+Nanoparticle+Decorated+Reduced+Graphene+Oxide+Composites+and+Their+Application+to+Photocurrent+Generation.">Environmentally Friendly, One&#8211;Pot Synthesis of Ag Nanoparticle Decorated Reduced Graphene Oxide Composites and Their Application to Photocurrent Generation.</a> Inorg. Chem. 51 (8), 4742-4746 (2012).</li><li>Tian, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three&#8211;Dimensional+Porous+Supramolecular+Architecture+from+Ultrathin+gC3N4+Nanosheets+and+Reduced+Graphene+Oxide:+Solution+Self-Assembly+Construction+and+Application+as+a+Highly+Efficient+Metal&#8211;Free+Electrocatalyst+for+Oxygen+Reduction+Reaction.">Three&#8211;Dimensional Porous Supramolecular Architecture from Ultrathin gC3N4 Nanosheets and Reduced Graphene Oxide: Solution Self-Assembly Construction and Application as a Highly Efficient Metal&#8211;Free Electrocatalyst for Oxygen Reduction Reaction.</a> ACS Appl. Mater. Interfaces. 6 (2), 1011-1017 (2014).</li><li>Liu, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stable+Aqueous+Dispersion+of+Graphene+Nanosheets:+Noncovalent+Functionalization+by+a+Polymeric+Reducing+Agent+and+Their+Subsequent+Decoration+with+Ag+Nanoparticles+for+Enzymeless+Hydrogen+Peroxide+Detection.">Stable Aqueous Dispersion of Graphene Nanosheets: Noncovalent Functionalization by a Polymeric Reducing Agent and Their Subsequent Decoration with Ag Nanoparticles for Enzymeless Hydrogen Peroxide Detection.</a> Macromolecules. 43 (23), 10078-10083 (2010).</li><li>Li, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photocatalytic+synthesis+of+highly+dispersed+Pd+nanoparticles+on+reduced+graphene+oxide+and+their+application+in+methanol+electro&#8211;oxidation.">Photocatalytic synthesis of highly dispersed Pd nanoparticles on reduced graphene oxide and their application in methanol electro&#8211;oxidation.</a> Catal. Sci. Technol. 2 (6), 1153-1156 (2012).</li></ol>

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Bestrahlung mit sichtbarem Licht auf GO Lösung für 30 min mit Gold-Nanopartikeln (AuNPs, AuNSs &amp; AuNRs) zeigte den schnellen Farbumschlag von hellgelb-braune bis schwarze Farbe (Abbildung 1). Um hochreines r-GO Produkt in hoher Ausbeute zu erhalten, gibt es zwei wichtige Faktoren zu folgen. Eine davon ist die Verwendung von AuNPs als effiziente plasmonic Katalysators, da AuNPs können stark das sichtbare Licht unter anderen Strukturen (dh AuNRs, AuNSs) absorbieren. Ein weiteres ist die Ve...

<html> Das erste entwickelte Scotch-Tape-basierte Methode 1 und chemische Gasphasenabscheidung 2 waren ausgezeichnet Methoden, um den ursprünglichen Zustand eines Graphen zu erzeugen, aber der Groß Graphen-Synthese oder Graphenschicht Bildung auf der Oberfläche mit großen Bereich haben als Schlüssel Begrenzung angesehen früheren Verfahren. 3 Eine mögliche Lösung für große R-GO Synthese naßchemischen synthetischen Verfahren, erfordert zunächst die Reaktionen mit starken Oxidationsmitteln, umfangreiche physikalische Behandlung wie Beschallung herzustellen GO Bogen und schließlich die Reduktion von Sauerstoff Funktionalitäten wie sein Hydroxy, Epoxid und Carbonylgruppen in GO ist wesentlich, um in seinen ursprünglichen physikalischen Eigenschaften zu gewinnen. 4 Teilweise wird die Reduktion von GO wurde entweder mit chemischen Verfahren unter Verwendung von Hydrazin oder seine Derivate 5 oder durch Wärmebehandlungsverfahren 550-1,100 ° durchgeführt ( C) in einer inerten oder reduzierenden Atmosphäre. 6 jove_content &quot;&gt; Diese Verfahren erfordern die giftigen Chemikalien, lange Reaktionszeit und hoher Temperatur, die Gesamtenergiebedarf für die r-GO Synthese erhöht. 7 Während die Foto-Bestrahlung Reduktionsverfahren, wie beispielsweise UV-induzierte, 8 photothermischen Verfahren unter Verwendung eines Xenon-Impuls Flash, 9 gepulsten Laser unterstützte 10 und photothermische Heizung mit Blitzlampen 11 sind auch für die Herstellung von gemeldet r-GO. Im Allgemeinen ist die geringe Effizienz der Umwandlung der photoinduzierten Verfahren auf die Verwendung von UV oder gepulste propagiert Laserbestrahlung, die hohe Photonenenergie liefern kann. Der geringe Energie von sichtbarem Licht Photonen schränkt seine Verwendung und nicht angezogen viel für r-GO-Synthese. Hervorragende Lichtabsorptionseigenschaften plasmonischer Nanopartikel im sichtbaren und / oder NIR-Bereich können die aktuellen Nachteile erheblich verbessern der Verwendung von sichtbarem Licht für r-GO-Synthese. 12,13 milden Reaktionsbedingungen kurze Reaktionszeit und begrenzter Verwendung toxischer chemicals könnte das sichtbare Licht induzierten Plasmonen-unterstützte photokatalytische Reduktion von GO als eine nützliche Alternative Methode zu machen. Im vorliegenden Verfahren beschreiben wir die effiziente und einfache r-GO Syntheseverfahren unter Verwendung von Plasmonen Nanopartikeln und sichtbares Licht. Der Reaktionsfortschritt wurde wie sphärische Gold-Nanopartikel (AuNPs), Gold-Nanostäbchen (AuNRs) und Gold nanostars (AuNSs) als stark abhängig von den Strukturen der Plasmonen Nanopartikel sein. Der Einsatz von AuNPs zeigten die wirksamste Verringerung der GO und die Nanopartikel leicht entfernbare und wiederverwertbare für den wiederholten Gebrauch (Abbildung 1). Die r-go mit sichtbarem Licht synthetisiert und AuNPs zeigten fast gleichen Qualität im Vergleich mit dem R-GO durch bekannte chemische Verfahren (Hydrazin), wie durch die Verwendung von verschiedenen analytischen Messungen und der Fluoreszenzlöschung / Recovery-basierte DNA-Nachweisverfahren nachgewiesen vorbereitet.

<table><tbody><tr><td>Cy3 modifeid ssDNA</td><td>IDT(Iowa, USA)</td><td></td><td>HPLC purified by IDT</td></tr><tr><td>Gold nanoparticles (30&amp;#160;nm)</td><td>Ted Pella, Inc(Redding, CA, USA).</td><td>15706-20</td><td>colloidal solution</td></tr><tr><td>4-(2-hydroxyethyl)-1-piperazineethane sulfonic acid (HEPES) (99.5%)</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>7365-45-9</td><td></td></tr><tr><td>Gold(III) Chloride Hydrate (99.999%)</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>&amp;nbsp;27988-77-8</td><td>strongly hygroscopic</td></tr><tr><td>Sodium Borohydride (99.99%)</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>16940-66-2</td><td></td></tr><tr><td>Hexadecyltrimethylammonium bromide (&amp;ge;99%)</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>57-09-0</td><td></td></tr><tr><td>L-Ascorbic Acid(&amp;ge;99.0%)</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>50-81-7</td><td></td></tr><tr><td>Sodium Chloride (99.5%)</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>7647-14-5</td><td></td></tr><tr><td>Silver Nitrate&amp;nbsp; (&amp;ge;99.0%)</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>7761-88-8</td><td></td></tr><tr><td>Graphite</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>7782-42-5</td><td></td></tr><tr><td>Sulfuric acid</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>7664-93-9</td><td></td></tr><tr><td>Phophoric acid</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>7664-38-2</td><td></td></tr><tr><td>Potassium permanganate</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>7722-64-7</td><td></td></tr><tr><td>Hydrogen peroxide</td><td>JUNSEI</td><td>23150-0350</td><td></td></tr><tr><td>Ammonium hydroxide</td><td>Sigma-Aldrich (St. Louis, MO, USA)</td><td>1336-21-6</td><td></td></tr><tr><td>Xe-lamp</td><td>&amp;nbsp;Cermax, Waltham, USA</td><td></td><td></td></tr><tr><td>NIR Laser</td><td>Class-IV, Sanctity Laser, Shanghai, China&amp;nbsp;</td><td></td><td>6W (output power)</td></tr><tr><td>UV-Vis spectrophotometer&amp;nbsp;</td><td>S-3100, SINCO, South Korea</td><td></td><td></td></tr><tr><td>Transmission Electron Microscopy</td><td>H-7650, Hitachi, Japan</td><td></td><td></td></tr><tr><td>Spectro Fluorometer</td><td>Jasco FP-6500, Tokyo, Japan</td><td></td><td></td></tr><tr><td>X-ray Photoelectron Spectrometer</td><td>AXIS&amp;ndash;NOVA, KRATOS Inc., UK</td><td></td><td></td></tr></tbody></table>

visible-light induced reduction of graphene oxide using plasmonic nanoparticle

Vorliegende Arbeit zeigt die einfachen, chemischen kostenlos, schnell und energieeffiziente Methode, um reduzierte Graphenoxid (r-GO) Lösung bei RT produzieren mit Bestrahlung mit sichtbarem Licht mit Plasmonen Nanopartikel. Die Plasmonen Nanopartikel verwendet, um die Reduktionseffizienz von GO zu verbessern. Es dauert nur 30 min bei RT durch Beleuchten der Lösungen mit Xe-Lampe, kann der R-GO-Lösungen von Goldnanopartikeln vollständigen Entfernung durch einfache Zentrifugation Schritt erhalten werden. Die kugelförmigen Goldnanopartikel (AuNPs) im Vergleich zu den anderen Nanostrukturen ist die geeignetste plasmonic Nanostruktur für r-GO Zubereitung. Mit sichtbarem Licht die reduzierte Graphenoxid vorbereitet und AuNPs war ebenso qualitative als chemisch reduzierte Graphenoxid, die durch verschiedene analytische Verfahren, wie UV-Vis-Spektroskopie, Raman-Spektroskopie, Pulver-XRD und XPS unterstützt wurde. Die reduzierte Graphenoxid mit sichtbarem Licht bereit zeigt hervorragende Löscheigenschaften über die Fluorzier Moleküle auf ssDNA und ausgezeichnete Fluoreszenz Recovery für Ziel-DNA-Detektion modifiziert. Die r-GO durch Recycling AuNPs hergestellt wird festgestellt, dass der gleiche Qualität mit der des chemisch reduziert r-GO können. Die Verwendung von sichtbarem Licht mit plasmonic Nanopartikel zeigt die gute Alternative Verfahren zur r-GO-Synthese.

Abbildung 1 zeigt die Gesamtschema für sichtbares Licht und Plasmonen-Nanopartikel auf der Basis r-GO Reduktionsreaktion. Abbildung 2 zeigt die instrumental-Setup für die Reaktionen. Nach der Reaktion ist es erforderlich, den Zentrifugationsschritt, um das verwendete Photokatalysator (AuNSs, AuNRs oder AuNPs), wie in 3A gezeigt, zu entfernen. Die HRTEM-Analyse zeigt das vollständige Entfernen von Nanopartikeln in dem Überstand (r-GO) (3B), die auch ...

Watch this Scientific Journal Video about Visible-light Induced Reduction of Graphene Oxide Using Plasmonic Nanoparticle at JoVE.com

Visible-light Induced Reduction of Graphene Oxide Using Plasmonic Nanoparticle

Ein einfaches Protokoll zur Herstellung von reduzierten Graphenoxids Verwendung von sichtbarem Licht und plasmonic Nanopartikel beschrieben.

Sichtbares Licht induzierte Reduktion von Graphenoxid Mit Plasmonische Nanopartikel

Present work demonstrates the simple, chemical free, fast, and energy efficient method to produce reduced graphene oxide (r-GO) solution at RT using ...

visible-light-induced-reduction-graphene-oxide-using-plasmonic

Research

JoVE Journal

Engineering

14.4K Aufrufe.  Korea University.  Ein einfaches Protokoll zur Herstellung von reduzierten Graphenoxids Verwendung von sichtbarem Licht und plasmonic Nanopartikel beschrieben. 

Serie: Visible-light Induced Reduction of Graphene Oxide Using Plasmonic Nanoparticle

Template Directed Synthesis of Plasmonic Gold Nanotubes with Tunable IR Absorbance

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) membranes have been under development since the 1990's and have become a common method to template the synthesis of high aspect ratio nanostructures, mostly by electrochemical growth or pore-wetting. Recently, these membranes have become commercially available in a wide range of pore sizes and densities, leading to an extensive library of functional nanostructures being synthesized from AAO membranes. These include composite nanorods, nanowires and nanotubes made of metals, inorganic materials or polymers 3-10. Nanoporous membranes have been used to synthesize nanoparticle and nanotube arrays that perform well as refractive index sensors, plasmonic biosensors, or surface enhanced Raman spectroscopy (SERS) substrates 11-16, as well as a wide range of other fields such as photo-thermal heating 17, permselective transport 18, 19, catalysis 20, microfluidics 21, and electrochemical sensing 22, 23. Here, we report a novel procedure to prepare gold nanotubes in AAO membranes. Hollow nanostructures have potential application in plasmonic and SERS sensing, and we anticipate these gold nanotubes will allow for high sensitivity and strong plasmon signals, arising from decreased material dampening 15.

Solution-suspendable gold nanotubes with controlled dimensions can be synthesized by electrochemical deposition in porous anodic aluminum oxide (AAO) membranes using a hydrophobic polymer core. Gold nanotubes and nanotube arrays hold promise for applications in plasmonic biosensing, surface-enhanced Raman spectroscopy, photo-thermal heating, ionic and molecular transport, microfluidics, catalysis and electrochemical sensing.

Template Gezielte Synthese von Plasmonic Gold-Nanoröhren mit einstellbaren IR Absorption

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) ...

Forschung

Chemie

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information support1,2,3. In this context, metal nanowires are especially desirable for realizing dense routing networks4. A prerequisite to operate such shared nanowire-based platform relies on our ability to electrically contact individual metal nanowires and efficiently excite surface plasmon polaritons5 in this information support. In this article, we describe a protocol to bring electrical terminals to chemically-synthesized silver nanowires6 randomly distributed on a glass substrate7. The positions of the nanowire ends with respect to predefined landmarks are precisely located using standard optical transmission microscopy before encapsulation in an electron-sensitive resist. Trenches representing the electrode layout are subsequently designed by electron-beam lithography. Metal electrodes are then fabricated by thermally evaporating a Cr/Au layer followed by a chemical lift-off. The contacted silver nanowires are finally transferred to a leakage radiation microscope for surface plasmon excitation and characterization8,9. Surface plasmons are launched in the nanowires by focusing a near infrared laser beam on a diffraction-limited spot overlapping one nanowire extremity5,9. For sufficiently large nanowires, the surface plasmon mode leaks into the glass substrate9,10. This leakage radiation is readily detected, imaged, and analyzed in the different conjugate planes in leakage radiation microscopy9,11. The electrical terminals do not affect the plasmon propagation. However, a current-induced morphological deterioration of the nanowire drastically degrades the flow of surface plasmons. The combination of surface plasmon leakage radiation microscopy with a simultaneous analysis of the nanowire electrical transport characteristics reveals the intrinsic limitations of such plasmonic circuitry.

Silver nanowires can simultaneously transport electrons and optical information in the form of surface plasmons. A procedure is described here to realize such a shared circuitry and the limitations at propagating both information carriers are evaluated.

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information ...

Ingenieurwesen

Utilization of Plasmonic and Photonic Crystal Nanostructures for Enhanced Micro- and Nanoparticle Manipulation

A method to manipulate the position and orientation of submicron particles nondestructively would be an incredibly useful tool for basic biological research. Perhaps the most widely used physical force to achieve noninvasive manipulation of small particles has been dielectrophoresis(DEP).1 However, DEP on its own lacks the versatility and precision that are desired when manipulating cells since it is traditionally done with stationary electrodes. Optical tweezers, which utilize a three dimensional electromagnetic field gradient to exert forces on small particles, achieve this desired versatility and precision.2 However, a major drawback of this approach is the high radiation intensity required to achieve the necessary force to trap a particle which can damage biological samples.3 A solution that allows trapping and sorting with lower optical intensities are optoelectronic tweezers (OET) but OET's have limitations with fine manipulation of small particles; being DEP-based technology also puts constraint on the property of the solution.4,5
This video article will describe two methods that decrease the intensity of the radiation needed for optical manipulation of living cells and also describe a method for orientation control. The first method is plasmonic tweezers which use a random gold nanoparticle (AuNP) array as a substrate for the sample as shown in Figure 1. The AuNP array converts the incident photons into localized surface plasmons (LSP) which consist of resonant dipole moments that radiate and generate a patterned radiation field with a large gradient in the cell solution. Initial work on surface plasmon enhanced trapping by Righini et al and our own modeling have shown the fields generated by the plasmonic substrate reduce the initial intensity required by enhancing the gradient field that traps the particle.6,7,8 The plasmonic approach allows for fine orientation control of ellipsoidal particles and cells with low optical intensities because of more efficient optical energy conversion into mechanical energy and a dipole-dependent radiation field. These fields are shown in figure 2 and the low trapping intensities are detailed in figures 4 and 5. The main problems with plasmonic tweezers are that the LSP's generate a considerable amount of heat and the trapping is only two dimensional. This heat generates convective flows and thermophoresis which can be powerful enough to expel submicron particles from the trap.9,10 The second approach that we will describe is utilizing periodic dielectric nanostructures to scatter incident light very efficiently into diffraction modes, as shown in figure 6.11 Ideally, one would make this structure out of a dielectric material to avoid the same heating problems experienced with the plasmonic tweezers but in our approach an aluminum-coated diffraction grating is used as a one-dimensional periodic dielectric nanostructure. Although it is not a semiconductor, it did not experience significant heating and effectively trapped small particles with low trapping intensities, as shown in figure 7. Alignment of particles with the grating substrate conceptually validates the proposition that a 2-D photonic crystal could allow precise rotation of non-spherical micron sized particles.10 The efficiencies of these optical traps are increased due to the enhanced fields produced by the nanostructures described in this paper.

Plasmonic tweezers and photonic crystal nanostructures are shown to produce useful enhancements in the efficiency and orientation control of optically trapping micro- and nano-particles.

Nutzung von Plasmonic und Photonic Crystal Nanostrukturen für verbesserte Mikro-und Nanopartikel-Manipulation

A method to manipulate the position and orientation of submicron particles nondestructively would be an incredibly useful tool for basic biological ...

Biotechnik

Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating

One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to neutral gold Au(0) by reducing agents, such as sodium citrate or sodium borohydride. The extension of this method to decorate iron oxide or similar nanoparticles with gold nanoparticles to create multifunctional hybrid Fe2O3-Au nanoparticles is straightforward. This approach yields fairly good control over Au nanoparticle dimensions and loading onto Fe2O3. Additionally, the Au metal size, shape, and loading can easily be tuned by changing experimental parameters (e.g., reactant concentrations, reducing agents, surfactants, etc.). An advantage of this procedure is that the reaction can be done in air or water, and, in principle, is amenable to scaling up. The use of such optically tunable Fe2O3-Au nanoparticles for hyperthermia studies is an attractive option as it capitalizes on plasmonic heating of gold nanoparticles tuned to absorb light strongly in the VIS-NIR region. In addition to its plasmonic effects, nanoscale Au provides a unique surface for interesting chemistries and catalysis. The Fe2O3 material provides additional functionality due to its magnetic property. For example, an external magnetic field could be used to collect and recycle the hybrid Fe2O3-Au nanoparticles after a catalytic experiment, or alternatively, the magnetic Fe2O3 can be used for hyperthermia studies through magnetic heat induction. The photothermal experiment described in this report measures bulk temperature change and nanoparticle solution mass loss as functions of time using infrared thermocouples and a balance, respectively. The ease of sample preparation and the use of readily available equipment are distinct advantages of this technique. A caveat is that these photothermal measurements assess the bulk solution temperature and not the surface of the nanoparticle where the heat is transduced and the temperature is likely to be higher.

Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating

We describe the synthesis and properties of multifunctional Fe2O3-Au nanoparticles produced by a wet chemical approach and investigate their photothermal properties using laser irradiation. The composite Fe2O3-Au nanoparticles retain the properties of both materials, creating a multifunctional structure with excellent magnetic and plasmonic properties.

Multifunktions-Hybrid Fe<sub&gt; 2</sub&gt; O<sub&gt; 3</sub&gt; -Au Nanopartikel für effiziente Plasmonische Heizung

One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to ...

In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

Combinations of metal oxide semiconductors and gold nanoparticles (AuNPs) have been investigated as new types of materials. The in situ synthesis of AuNPs within the interlayer space of semiconducting layered titania nanosheet (TNS) films was investigated here. Two types of intermediate films (i.e., TNS films containing methyl viologen (TNS/MV2+) and 2-ammoniumethanethiol (TNS/2-AET+)) were prepared. The two intermediate films were soaked in an aqueous tetrachloroauric(III) acid (HAuCl4) solution, whereby considerable amounts of Au(III) species were accommodated within the interlayer spaces of the TNS films. The two types of obtained films were then soaked in an aqueous sodium tetrahydroborate (NaBH4) solution, whereupon the color of the films immediately changed from colorless to purple, suggesting the formation of AuNPs within the TNS interlayer. When only TNS/MV2+ was used as the intermediate film, the color of the film gradually changed from metallic purple to dusty purple within 30 min, suggesting that aggregation of AuNPs had occurred. In contrast, this color change was suppressed by using the TNS/2-AET+ intermediate film, and the AuNPs were stabilized for over 4 months, as evidenced by the characteristic extinction (absorption and scattering) band from the AuNPs.

In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

Here, we present a protocol for the in situ synthesis of gold nanoparticles (AuNPs) within the interlayer space of layered titanate films without the aggregation of AuNPs. No spectral change was observed even after 4 months. The synthesized material has expected applications in catalysis, photo-catalysis, and the development of cost-effective plasmonic devices.

In - situ - Synthese von Gold - Nanopartikeln ohne Aggregation zwischen die Schichten von Layered - Titanat OHP - Folien

Combinations of metal oxide semiconductors and gold nanoparticles (AuNPs) have been investigated as new types of materials. The in situ synthesis of AuNPs ...

Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing in combination with new nanofabrication techniques. A plasmon is a quantum of charge density oscillation that lends nanoscale metals such as gold and silver unique optical properties. In particular, gold and silver nanoparticles exhibit localized surface plasmon resonances-collective charge density oscillations on the surface of the nanoparticle-in the visible spectrum. Here, we focus on the fabrication of periodic arrays of anisotropic plasmonic nanostructures. These half-shell (or nanocup) structures can exhibit additional unique light-bending and polarization-dependent optical properties that simple isotropic nanostructures cannot. Researchers are interested in the fabrication of periodic arrays of nanocups for a wide variety of applications such as low-cost optical devices, surface-enhanced Raman scattering, and tamper indication. We present a scalable technique based on colloidal lithography in which it is possible to easily fabricate large periodic arrays of nanocups using spin-coating and self-assembled commercially available polymeric nanospheres. Electron microscopy and optical spectroscopy from the visible to near-infrared (near-IR) was performed to confirm successful nanocup fabrication. We conclude with a demonstration of the transfer of nanocups to a flexible, conformal adhesive film.

We demonstrate the fabrication of periodic gold nanocup arrays using colloidal lithographic techniques and discuss the importance of nanoplasmonic films.

Herstellung von periodischen Gold Nanocup Arrays mit kolloidalen Lithographie

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing ...

Determination of the Excitation and Coupling Rates Between Light Emitters and Surface Plasmon Polaritons

We have developed a unique method to measure the excitation and coupling rates between the light emitters and surface plasmon polaritons (SPPs) arising from metallic periodic arrays without involving time-resolved techniques. We have formulated the rates by quantities that can be measured by simple optical measurements. The instrumentation based on angle- and polarization-resolved reflectivity and photoluminescence spectroscopy will be described in detail here. Our approach is intriguing due to its simplicity, which requires routine optics and several mechanical stages, and thus is highly affordable to most of the research laboratories.

This protocol describes the instrumentation for determining the excitation and coupling rates between light emitters and Bloch-like surface plasmon polaritons arising from periodic arrays.

Bestimmung der Erregung und Kupplung zwischen Lichtemittern und Oberflächen Plasmon Polaritonen

We have developed a unique method to measure the excitation and coupling rates between the light emitters and surface plasmon polaritons (SPPs) arising ...

Performing Spectroscopy on Plasmonic Nanoparticles with Transmission-Based Nomarski-Type Differential Interference Contrast Microscopy

Differential interference contrast (DIC) microscopy is a powerful imaging tool that is most commonly employed for imaging microscale objects using visible-range light. The purpose of this protocol is to detail a proven method for preparing plasmonic nanoparticle samples and performing single particle spectroscopy on them with DIC microscopy. Several important steps must be followed carefully in order to perform repeatable spectroscopy experiments. First, landmarks can be etched into the sample substrate, which aids in locating the sample surface and in tracking the region of interest during experiments. Next, the substrate must be properly cleaned of debris and contaminants that can otherwise hinder or obscure examination of the sample. Once a sample is properly prepared, the optical path of the microscope must be aligned, using Kohler Illumination. With a standard Nomarski style DIC microscope, rotation of the sample may be necessary, particularly when the plasmonic nanoparticles exhibit orientation-dependent optical properties. Because DIC microscopy has two inherent orthogonal polarization fields, the wavelength-dependent DIC contrast pattern reveals the orientation of rod-shaped plasmonic nanoparticles. Finally, data acquisition and data analyses must be carefully performed. It is common to represent DIC-based spectroscopy data as a contrast value, but it is also possible to present it as intensity data. In this demonstration of DIC for single particle spectroscopy, the focus is on spherical and rod-shaped gold nanoparticles.

The goal of this protocol is to detail a proven approach for the preparation of plasmonic nanoparticle samples and for performing single particle spectroscopy on them with differential interference contrast (DIC) microscopy.

Durchführung der Spektroskopie über plasmonische Nanopartikel mit transmissionsbasierten Nomarski-Typ-Differentialinterferenz-Interferenz-Kontrahenten Mikroskopie

Differential interference contrast (DIC) microscopy is a powerful imaging tool that is most commonly employed for imaging microscale objects using ...

Photodeposition of Pd onto Colloidal Au Nanorods by Surface Plasmon Excitation

A protocol is described to photocatalytically guide Pd deposition onto Au nanorods (AuNR) using surface plasmon resonance (SPR). Excited plasmonic hot electrons upon SPR irradiation drive reductive deposition of Pd on colloidal AuNR in the presence of [PdCl4]2-. Plasmon-driven reduction of secondary metals potentiates covalent, sub-wavelength deposition at targeted locations coinciding with electric field &#8220;hot-spots&#8221; of the plasmonic substrate using an external field (e.g., laser). The process described herein details a solution-phase deposition of a catalytically-active noble metal (Pd) from a transition metal halide salt (H2PdCl4) onto aqueously-suspended, anisotropic plasmonic structures (AuNR). The solution-phase process is amenable to making other bimetallic architectures. Transmission UV-vis monitoring of the photochemical reaction, coupled with ex situ XPS and statistical TEM analysis, provide immediate experimental feedback to evaluate properties of the bimetallic structures as they evolve during the photocatalytic reaction. Resonant plasmon irradiation of AuNR in the presence of [PdCl4]2- creates a thin, covalently-bound Pd0 shell without any significant dampening effect on its plasmonic behavior in this representative experiment/batch. Overall, plasmonic photodeposition offers an alternative route for high-volume, economical synthesis of optoelectronic materials with sub-5 nm features (e.g., heterometallic photocatalysts or optoelectronic interconnects).

A protocol for anisotropic photodeposition of Pd onto aqueously-suspended Au nanorods via localized surface plasmon excitation is presented.

Photodeposition von Pd auf kolloidale Au Nanostäbe durch Surface Plasmon Erregung

A protocol is described to photocatalytically guide Pd deposition onto Au nanorods (AuNR) using surface plasmon resonance (SPR). Excited plasmonic hot ...

Graphene-Assisted Quasi-van der Waals Epitaxy of AlN Film on Nano-Patterned Sapphire Substrate for Ultraviolet Light Emitting Diodes

This protocol demonstrates a method for graphene-assisted quick growth and coalescence of AlN on nano-pattened sapphire substrate (NPSS). Graphene layers are directly grown on NPSS using catalyst-free atmospheric-pressure chemical vapor deposition (APCVD). By applying nitrogen reactive ion etching (RIE) plasma treatment, defects are introduced into the graphene film to enhance chemical reactivity. During metal-organic chemical vapor deposition (MOCVD) growth of AlN, this N-plasma treated graphene buffer enables AlN quick growth, and coalescence on NPSS is confirmed by cross-sectional scanning electron microscopy (SEM). The high quality of AlN on graphene-NPSS is then evaluated by X-ray rocking curves (XRCs) with narrow (0002) and (10-12) full width at half-maximum (FWHM) as 267.2 arcsec and 503.4 arcsec, respectively. Compared to bare NPSS, AlN growth on graphene-NPSS shows significant reduction of residual stress from 0.87 GPa to 0.25 Gpa, based on Raman measurements. Followed by AlGaN multiple quantum wells (MQWS) growth on graphene-NPSS, AlGaN-based deep ultraviolet light-emitting-diodes (DUV LEDs) are fabricated. The fabricated DUV-LEDs also demonstrate obvious, enhanced luminescence performance. This work provides a new solution for the growth of high quality AlN and fabrication of high performance DUV-LEDs using a shorter process and less costs.

A protocol for graphene-assisted growth of high-quality AlN films on nano-patterned sapphire substrate is presented.

Graphen-Assisted Quasi-van der Waals Epitaxy von AlN Film auf Nano-PatternEd Sapphire Substrat für ultraviolette Leuchtdioden

This protocol demonstrates a method for graphene-assisted quick growth and coalescence of AlN on nano-pattened sapphire substrate (NPSS). Graphene layers ...