This research was supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada, the Canada Research Chairs Program, and Simon Fraser University. This work made use of 4D LABS shared facilities supported by the Canada Foundation for Innovation (CFI), British Columbia Knowledge Development Fund (BCKDF) and Simon Fraser University.

1. Síntese do 4 NaYF / Yb 3+ / Er 3+ Upconverting Nanopartículas (UCNP) <ol><li> Configure o aparelho como se segue: <ol><li> Coloque um manto de aquecimento 250 ml em uma placa de agitação regular e ligue o manto para o casal térmica. </li><li> Coloque um bal de fundo redondo de 250 ml equipado com uma barra de agitação magnética para a manta de aquecimento com aperto apropriado. </li><li> Conecte um adaptador de ar para o pescoço esquerdo do balão de fundo redondo e conectar esse adaptador de ar para a linha de Schlenk com tubos de plástico. </li><li> Anexe um adaptador de vidro para o pescoço direito do balão de fundo redondo e fixar um adaptador de termômetro para o adaptador de vidro. Inserir a sonda de temperatura para o balão através do adaptador termômetro e ligue-a a par termoeléctrico. </li><li> Anexar uma cabeça de destilação para o pescoço meio do frasco de fundo redondo. Coloque um bujão na parte superior da cabeça de destilação. Ligue a cabeça para um condensador, seguindo-se um vácuo distillatAdaptador de iões e um balão de fundo redondo de 50 ml. Conecte o adaptador de destilação a vácuo para um bubbler através de tubos de plástico. </li></ol></li><li> Pesar 1,17 g (3,9 mmol) de acetato de ítrio, 0,439 g de acetato de itérbio e 0,0727 g (0,1 mmol) de acetato de érbio e colocá-los na reacção balão de fundo redondo. </li><li> Adicionar 30 ml de ácido oleico e 75 ml de octadeceno ao frasco utilizando uma proveta graduada. </li><li> Lavar o lado da reacção balão de fundo redondo utilizando 5 ml de metanol para se certificar de que não o ácido oleico e octadeceno está presa às paredes do balão de reacção. </li><li> Ligue o balão de reacção para uma linha de Schlenk colector duplo e transformar a válvula correspondente para manter o balão de reacção ligada à linha de azoto. </li><li> Ligue o termopar, ajustar a temperatura a 80 ° C, e gradualmente aquecer o sistema a esta temperatura. A 80 ° C e depois de todos os materiais de partida são dissolvidos, remover a manta de aquecimento e para permitir que a reacçãoarrefecer a 30 ° C. </li><li> Quando a temperatura chega a 30 ° C, tirar a cabeça de destilação, mude o adaptador de ar a partir do pescoço para a esquerda para o meio do pescoço e feche o pescoço esquerda com uma rolha. Lentamente introduzir vácuo ao balão de reacção, rodando a válvula na linha de Schlenk a partir da linha de azoto para a linha de vácuo. Todos os componentes de baixo ponto de ebulição irá ser puxado para fora a partir da reacção neste ponto. </li><li> Quando a solução deixar de borbulhar, elevar-se a temperatura para 115 ° C a uma velocidade de 5 ° C / min. </li><li> Uma vez que a temperatura atinge 115 ° C, manter esta temperatura durante 15 min, depois remover a manta de aquecimento e arrefecer a reacção a 50 ° C. Em seguida, alternar rapidamente a configuração de volta à forma original por recolocar a cabeça de destilação para o pescoço meio eo adaptador de ar para a cabeça esquerda. </li><li> Pesar 0,74 g (12,5 mmol) de NaOH e 0,50 g (20,0 mmol) de NH 4 F, durante o processo de arrefecimento, e dissolvê-losem 50 ml de metanol por sonicação. </li><li> Após sonicação, verter a solução de reacção para o balão de fundo redondo e lavar as paredes do balão com 5 ml de MeOH. </li><li> Deixar a solução agitar a 50 ° C durante 30 min. </li><li> Aumentar a temperatura para 75 ° C para destilar o metanol. </li><li> Durante a destilação, esvaziar o balão de recolha quando necessário. Após a destilação é terminada, aquecer a reacção a 300 ° C sob protecção de azoto tão rápido quanto possível. </li><li> Uma vez que a temperatura atinge 300 ° C, manter esta temperatura durante 1 h. Se necessário, cobrir a configuração com folha de alumínio para ajudar a manter a temperatura. Em seguida, remover fonte de calor e deixar a reacção arrefecer até à temperatura ambiente. </li><li> Uma vez que é resfriado a temperatura ambiente, a solução uniformemente dividida em três tubos de centrifugação (50 ml tubos, cerca de 35 ml de solução por cada tubo), e encher o tubo para os 50 ml escala utilizando etanol anidro. Centrífuga tudo tele tubos a 3400 xg durante 15 min. Após centrifugação, as UCNPs deve ser observado no lado dos tubos como um precipitado branco. </li><li> Descartar o sobrenadante e redispersar os peletes UCNPs em hexanos (7,5 mL de hexanos por cada tubo), em seguida, encher o tubo com etanol para a escala de 50 ml. Tubos Centrifugar novamente a 3400 xg durante 15 min. </li><li> Uma vez que a centrifugação é completa, descartar o sobrenadante e redispersar os UCNPs sólidos em 30 ml de CHCl 3 para utilização posterior. </li></ol> 2. Nanoassemblies Assembleia da água dispersíveis contendo orgânicos Dye Moléculas e Upconverting Nanopartículas <ol><li> Dissolve-se 25 mg (0,0147 mmol) de poli (anidrido maleico estireno-alt) (PSMA) em 3 ml de CHCI3 num frasco de cintilação equipado com uma barra de agitação magnética. Esta quantidade é uma quantidade otimizada após várias tentativas. </li><li> Adicionar 250 ul (47 mg / ml) da solução de estoque upconverting nanopartículas clorofórmio ao scintifrasco llation. </li><li> Tapar o frasco e colocá-lo na placa de agitação magnética, e agitou-se a solução à temperatura ambiente durante 2 h. </li><li> Pesar 160 mg (0,0773 mmol) de poliéter amina 2070, e dissolvê-lo em 1 ml de CHCl3. Em seguida, adicionar esta solução ao frasco de cintilação numa porção, utilizando uma pipeta. A solução torna-se a amarelo pálido, indicando que a reacção de poliéter amina 2070 com os grupos anidrido no PSMA. </li><li> Continuar a agitar a solução durante a noite à temperatura ambiente. </li><li> Medir a quantidade adequada de moléculas de corante orgânico, em seguida, dispensam-lo dentro do frasco de cintilação numa porção, agita-se a solução resultante durante 1 hora. <ol><li> Para a amostra TPP-NP (nanoassembly contendo shell de polímero, tetrafenil porfirina e nanopartículas upconverting), diretamente adicionar 1 mg de tetrafenil porfirina para o frasco de cintilação. Para a amostra DAE-UCNP (nanoassembly contendo casca de polímeros, moléculas diarylethene e upconverting nanopartículas), a quantidade de cada uma das moléculas diarylethene é 2 x 10 -7 mol. Adicionar as duas moléculas diarylethene dentro da solução reaccional. Os volumes para as duas moléculas são diarylethene: DAE-1o (1,8 mM), 111 ul e DAE-2o (1,6 mM), 125 ul. </li></ol></li><li> Remover o solvente CHCI3 sob pressão reduzida utilizando um evaporador rotativo, em seguida, adicionar 3 ml de 0,001 M de NaOH aquoso (pH ≈ 11) para o frasco de cintilação, em seguida, sonicar o frasco até uma suspensão leitosa é formado. </li><li> Colocar o frasco de volta no evaporador rotativo, e cuidadosamente remover o restante CHCI3 até que a suspensão se transformou a uma solução clara. </li><li> Transferir a solução do frasco de cintilação para tubos de centrifugação cónicos de 1,5 ml dois, depois centrifugar a solução a 20.600 xg durante 25 min. </li><li> Rejeitar o sobrenadante, adicionar em seguida um total de 3 ml de H2O desionizada para os dois tubos (1,5 ml por tubo), sonicar os tubos para redispersar os peletesno desionizada H 2 O. </li><li> Centrifugar os dois tubos novamente em 20.600 xg durante 25 min. </li><li> Rejeitar o sobrenadante, adicionar em seguida um total de 3 ml de H2O desionizada para os dois tubos (1,5 ml por tubo). Sonicar os tubos para redispersar os peletes no desionizada H 2 O. </li><li> Filtrar a amostra dispersão aquosa de nanopartículas através de um filtro de seringa de 0,2 | iM para se obter a amostra final para mais testes. </li></ol>

<ol>
	<li>Fery-Forgues, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+organic+nanocrystals+and+non-doped+nanoparticles+for+biological+applications.">Fluorescent organic nanocrystals and non-doped nanoparticles for biological applications.</a> Nanoscale. 5 (18), 8428-8442 (2013).</li><li>Vollrath, A., Schubert, S., Schubert, U. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescence+imaging+of+cancer+tissue+based+on+metal-free+polymeric+nanoparticles.">Fluorescence imaging of cancer tissue based on metal-free polymeric nanoparticles.</a> J. Mater. Chem. B. 1, 1994-2007 (2013).</li><li>Cheng, X., Lowe, S. B., Reecec, P. J., Gooding, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Colloidal+silicon+quantum+dots:+from+preparation+to+the+modification+of+self-assembled+monolayers+(SAMs)+for+bio-applications.">Colloidal silicon quantum dots: from preparation to the modification of self-assembled monolayers (SAMs) for bio-applications.</a> Chem. Soc. Rev. 43, 2680-2700 (2014).</li><li>Luo, P. G., 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=Carbon-based+quantum+dots+for+fluorescence+imaging+of+cells+and+tissues.">Carbon-based quantum dots for fluorescence imaging of cells and tissues.</a> RSC Adv. 4, 10791-10807 (2014).</li><li>Wang, Y., Hu, R., Lin, G., Roy, I., Yong, K. -. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functionalized+Quantum+Dots+for+Biosensing+and+Bioimaging+and+Concerns+on+Toxicity.">Functionalized Quantum Dots for Biosensing and Bioimaging and Concerns on Toxicity.</a> ACS Appl. Mater. Interfaces. 5 (8), 2786-2799 (2013).</li><li>Kairdolf, B. 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=Semiconductor+Quantum+Dots+for+Bioimaging+and+Biodiagnostic+Applications.">Semiconductor Quantum Dots for Bioimaging and Biodiagnostic Applications.</a> Annu. Rev. Anal. Chem. 6 (1), 143-162 (2013).</li><li>Huang, B., Bates, M., Zhuang, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Super-Resolution+Fluorescence+Microscopy.">Super-Resolution Fluorescence Microscopy.</a> Annu. Rev. Biochem. 78, 993-1016 (2009).</li><li>F&#246;lling, 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=Photochromic+Rhodamines+Provide+Nanoscopy+with+Optical+Sectioning.">Photochromic Rhodamines Provide Nanoscopy with Optical Sectioning.</a> Angew. Chem. Int. Ed. 46 (33), 6266-6270 (2007).</li><li>F&#246;lling, 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=Fluorescence+Nanoscopy+with+Optical+Sectioning+by+Two-Photon+Induced+Molecular+Switching+using+Continuous-Wave+Lasers.">Fluorescence Nanoscopy with Optical Sectioning by Two-Photon Induced Molecular Switching using Continuous-Wave Lasers.</a> Chem. Phys. Chem. 9 (2), 321-326 (2008).</li><li>Bossi, M., 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=Multicolor+Far-Field+Fluorescence+Nanoscopy+through+Isolated+Detection+of+Distinct+Molecular+Species.">Multicolor Far-Field Fluorescence Nanoscopy through Isolated Detection of Distinct Molecular Species.</a> Nano Lett. 8 (8), 2463-2468 (2008).</li><li>Berns, M. W., Krasieva, T., Sun, C. &. #. 8. 2. 1. 1. ;. H., Dvornikov, A., Rentzepis, P. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+polarity+dependent+fluorescence+"switch"+in+live+cells.">A polarity dependent fluorescence "switch" in live cells.</a> Photochem. Photobiol. B: Biol. 75, 51-56 (2004).</li><li>Zou, 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=Amphiphilic+Diarylethene+as+a+Photoswitchable+Probe+for+Imaging+Living+Cells.">Amphiphilic Diarylethene as a Photoswitchable Probe for Imaging Living Cells.</a> J. Am. Chem. Soc. 130 (47), 15750-1 (2008).</li><li>Westphal, V., 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=Video-Rate+Far-Field+Optical+Nanoscopy+Dissects+Synaptic+Vesicle+Movement.">Video-Rate Far-Field Optical Nanoscopy Dissects Synaptic Vesicle Movement.</a> Science. 320, 246-249 (2008).</li><li>Zhuang, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+Switches+Based+on+Photochromic+Compounds.">Fluorescent Switches Based on Photochromic Compounds.</a> Nat Photonics. 3, 365-367 (2009).</li><li>Cusido, J., Deniz, E., Raymo, F. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+Switches+Based+on+Photochromic+Compounds.">Fluorescent Switches Based on Photochromic Compounds.</a> Eur. J. Org. Chem. 13, 2031-2045 (2009).</li><li>Raymo, F. M., Tomasulo, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron+and+energy+transfer+modulation+with+photochromic+switches.">Electron and energy transfer modulation with photochromic switches.</a> Chem. Soc. Rev. 34, 327-336 (2005).</li><li>Feringa, B. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Molecular Switches. , (2010).</li><li>Tian, H., Yang, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+progresses+on+diarylethene+based+photochromic+switches.">Recent progresses on diarylethene based photochromic switches.</a> Chem. Soc. Rev. 33, 85-97 (2004).</li><li>Ubaghs, L., Sud, D., Branda, N. R., Perepichka, I. D., Perepichka, D., Branda, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Handbook in Thiophene-Based Materials: Applications in Organic Electronics and Photonics. 2, (2009).</li><li>Norsten, T. B., Branda, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoregulation+of+Fluorescence+in+a+Porphyrinic+Dithienylethene+Photochrome.">Photoregulation of Fluorescence in a Porphyrinic Dithienylethene Photochrome.</a> J. Am. Chem. Soc. 123 (8), 1784-1785 (2001).</li><li>Giordano, L., Jovin, T. M., Irie, M., Jares-Erijman, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diheteroarylethenes+as+Thermally+Stable+Photoswitchable+Acceptors+in+Photochromic+Fluorescence+Resonance+Energy+Transfer+(pcFRET).">Diheteroarylethenes as Thermally Stable Photoswitchable Acceptors in Photochromic Fluorescence Resonance Energy Transfer (pcFRET).</a> J. Am. Chem. Soc. 124 (25), 7481-7489 (2002).</li><li>F&#246;lling, 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=Synthesis+and+Characterization+of+Photoswitchable+Fluorescent+Silica+Nanoparticles.">Synthesis and Characterization of Photoswitchable Fluorescent Silica Nanoparticles.</a> Small. 4 (1), 134-142 (2008).</li><li>Jeong, 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=Photoreversible+cellular+imaging+using+photochrome-conjugated+fullerene+silica+nanoparticles.">Photoreversible cellular imaging using photochrome-conjugated fullerene silica nanoparticles.</a> Chem. Commun. 47, 10668-10670 (2011).</li><li>Gai, S., Li, C., Yang, P., Lin, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+progress+in+rare+earth+micro/nanocrystals:+soft+chemical+synthesis,+luminescent+properties,+and+biomedical+applications.">Recent progress in rare earth micro/nanocrystals: soft chemical synthesis, luminescent properties, and biomedical applications.</a> Chem. Rev. 114 (4), 2343-2389 (2014).</li><li>Carling, C. -. J., Boyer, J. -. C., Branda, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multimodal+fluorescence+modulation+using+molecular+photoswitches+and+upconverting+nanoparticles.">Multimodal fluorescence modulation using molecular photoswitches and upconverting nanoparticles.</a> Org. Biomol. Chem. 10, 6159-6168 (2012).</li><li>Wu, T., Boyer, J. -. C., Barker, M., Wilson, D., Branda, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+"Plug-and-Play"+Method+to+Prepare+Water-Soluble+Photoresponsive+Encapsulated+Upconverting+Nanoparticles+Containing+Hydrophobic+Molecular+Switches.">A "Plug-and-Play" Method to Prepare Water-Soluble Photoresponsive Encapsulated Upconverting Nanoparticles Containing Hydrophobic Molecular Switches.</a> Chem. Mater. 25 (12), (2013).</li><li>Wu, T., Kaur, S., Branda, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Energy+transfer+between+amphiphilic+porphyrin+polymer+shells+and+upconverting+nanoparticle+cores+in+water-dispersible+nano-assemblies.">Energy transfer between amphiphilic porphyrin polymer shells and upconverting nanoparticle cores in water-dispersible nano-assemblies.</a> Org. Biol. Chem. 13, 2317-2322 (2015).</li><li>Irie, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photochromism:+Memories+and+Switches+Introduction.">Photochromism: Memories and Switches Introduction.</a> Chem. Rev. 100 (5), 1683-1684 (2000).</li></ol>

The authors have nothing to disclose.

As nanopartículas sintetizado de acordo com este protocolo tem uma distribuição de tamanho de 20 a 25 nm centrada em torno de 22,5 26,27 nm. Eles podem ser classificados como partículas esféricas com uma estrutura de rede 4 de acolhimento α-NaYF. Existem dois passos críticos neste protocolo. Na síntese UCNP, é crucial para manter a temperatura de aquecimento e tempo tão preciso quanto possível para assegurar uma distribuição estreita de tamanho de partícula. A adição simultânea de ...

Hoje ainda há uma necessidade urgente de desenvolver novos tipos de agentes de bio-imagem. Muitas novas sondas fluorescentes têm sido bem documentadas. 1-6 No entanto, melhorias substanciais na resolução de imagem continua a ser um desafio. 7 Um método prático é para modular directamente as sondas de fluorescência entre um estado emissivo &#39;light&#39; e um estado extinta &#39;dark&#39;. 12/08 Este método particular tem sido aplicado no desenvolvimento de tecnologias como o empobrecimento da emissão estimulada (STED) microscopia 13 e microscopia óptica reconstrução estocástico (STORM). 14 Outra abordagem para modular a fluorescência é acoplar cromóforos fotossensíveis juntamente com sondas fluorescentes. 15,16 Alternando o cromóforo fotossensíveis entre dois isómeros em que apenas um dos isómeros pode actuar como um aceitador de transferência de energia eficiente, permite o controle sobre extinção da fluorescência do po dee sonda através de transferência Förster Ressonância Energia (FRET) e outros mecanismos. O resultado é a criação de um estado emissiva e extinguiu-se um estado que pode ser alternado por exposição do cromóforo fotossensíveis para diferentes comprimentos de onda de luz. Cromóforos diarylethene fotossensíveis pode ser reversivelmente alternada entre um isómero de anel aberto incolor e um isómero de anel fechado de cor após irradiação com UV e luz visível 17-19 A estabilidade térmica dos dois isómeros e os espectros de absorção sintonizável do anel fechado composição isómero. diarylethenes muito bons candidatos como FRET controlável aceitantes. nanopartículas 20-23 Lanthanide dopado NaYF 4 upconverting são úteis para bio-imagem. 24 Estas nanopartículas absorvem a luz infravermelha próxima e emitem luz em várias regiões do espectro visível. Exemplos de modulação de fluorescência através da combinação de cromóforos diarylethene fotossensíveis e nanopartículas foram previamenteriormente relatado pelo nosso grupo. 25-27 No entanto, os sistemas descritos em cada exemplo necessária uma modificação sintética adicional para unir as diarylethenes à superfície das nanopartículas, o que complica o desenvolvimento de sistemas mais diversos. Aqui demonstramos um método simples &quot;plug-and-play &#39;para preparar moléculas de corante orgânico dispersíveis em água e nanopartículas fotossensíveis upconverting usando uma estratégia de auto-montagem. A escolha dos polímeros; poli (anidrido maleico estireno-alt) e poliéter amina 2,070 fornecer um ambiente hidrofílico e hidrofóbico. As secções hidrófobas do polímero ajuda a manter as moléculas orgânicas insolúveis em água e normalmente nanopartículas upconverting juntos, enquanto que a região hidrófila do polímero é essencial para manter a solubilidade em água. Vamos primeiro demonstrar síntese das nanopartículas upconverting pelo método de nucleação térmica. Então, vamos provar how as moléculas orgânicas e nanopartículas upconverting são encapsulados dentro de regiões hidrofóbicas do invólucro de polímero e permanecem estáveis ​​em meio aquoso por simplesmente co-agitação de uma solução do nanopartículas upconverting, polímero e diferentes moléculas de corantes orgânicos, seguido por um procedimento de trabalho conveniente. Nós também demonstrar como para modular a emissão de fluorescência das montagens usando a irradiação de luz externa. Nós antecipamos o âmbito da utilização deste método &#39;plug-and-play &quot;para fazer nanoassemblies dispersíveis em água continuará a se expandir.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>yttrium acetate</td>
			<td>sigma</td>
			<td>326046</td>
			<td>Yttrium(III) acetate hydrate</td>
		</tr>
		<tr>
			<td>ytterbium acetate</td>
			<td>sigma</td>
			<td>544973</td>
			<td>&#160;Ytterbium(III) acetate hydrate&#160;</td>
		</tr>
		<tr>
			<td>erbium acetate</td>
			<td>sigma</td>
			<td>325570</td>
			<td>Erbium(III) acetate hydrate</td>
		</tr>
		<tr>
			<td>oleic acid</td>
			<td>sigma</td>
			<td>75096</td>
			<td>analytical standard</td>
		</tr>
		<tr>
			<td>octadecene</td>
			<td>sigma</td>
			<td>O806&#160;</td>
			<td>Technical grade&#160;</td>
		</tr>
		<tr>
			<td>NaOH</td>
			<td></td>
			<td>S5881&#160;</td>
			<td>reagent grade</td>
		</tr>
		<tr>
			<td>NH4F</td>
			<td></td>
			<td>216011</td>
			<td>ACS reagent</td>
		</tr>
		<tr>
			<td>poly(styrene-alt-maleic anhydride)</td>
			<td>sigma</td>
			<td>4422699</td>
			<td>Average Mn= 1700</td>
		</tr>
		<tr>
			<td>JeffAmine 2070</td>
			<td>Huntsman</td>
			<td>M-2070</td>
			<td></td>
		</tr>
		<tr>
			<td>Varian Carry 300</td>
			<td>Agilent</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>JDSU NIR laser</td>
			<td>JSDU</td>
			<td>L4-9897510-100M</td>
			<td>980 nm diode laser</td>
		</tr>
	</tbody>
</table>

a 'plug and play' method to create water-dispersible nanoassemblies containing an amphiphilic polymer, organic dyes and upconverting nanoparticles

In this protocol, we first describe a procedure to synthesize lanthanide doped upconverting nanoparticles (UCNPs). We then demonstrate how to generate amphiphilic polymers in situ, and describe a protocol to encapsulate the prepared UCNPs and different organic dye molecules (porphyrins and diarylethenes) using polymer shells to form stable water-dispersible nanoassemblies. The nanoassembly samples containing both the UCNPs and the diarylethene organic dyes have interesting photochemical and photophysical properties. Upon 365 nm UV irradiation, the diarylethene group undergoes a visual color change. When the samples are irradiated with visible light of another specific wavelength, the color fades and the samples return to the initial colorless state. The samples also emit visible light from the UCNPs upon irradiation with 980 nm near-infrared light. The emission intensity of the samples can be tuned through alternate irradiation with UV and visible light. Modulation of fluorescence can be performed for many cycles without observable degradation of the samples. This versatile encapsulation procedure allows for the transfer of hydrophobic molecules and nanoparticles from an organic solvent to an aqueous medium. The polymer helps to maintain a lipid-like microenvironment for the organic molecules to aid in preservation of their photochemical behavior in water. Thus this method is ideal to prepare water-dispersible photoresponsive systems. The use of near-infrared light to activate upconverting nanoparticles allows for lower energy light to be used to activate photoreactions instead of more harmful ultraviolet light.

Espectros de absorção e espectros de fotoluminescência foram coletadas para amostra DAE-UCNP. Os espectros de absorção são usados ​​para comparar a sobreposição espectral entre os cromóforos diarylethene fechadas e as nanopartículas upconverting. As fotografias das amostras (tanto TPP-UCNP e DAE-UCNP) também foram incluídos para demonstrar a encapsulação bem sucedida das moléculas de corante e nanopartículas upconverting orgânicos, que estão localizados dentro das conchas polímero anfifílico na f...

Watch this Scientific Journal Video about A 'Plug and Play' Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles at JoVE.com

A &#039;Plug and Play&#039; Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles

Organic dye molecules and oleic acid coated upconverting nanoparticles are not water-soluble. This protocol describes a &#8216;plug and play&#8217; method that enables the transfer of organic dye molecules and upconverting particles from their initial hydrophobic solvent to water.

Um método &#39;Plug and Play&#39; para criar Nanoassemblies dispersáveis ​​em água contendo um polímero anfifílicas, corantes orgânicos e Upconverting Nanopartículas

In this protocol, we first describe a procedure to synthesize lanthanide doped upconverting nanoparticles (UCNPs). We then demonstrate how to generate ...

a-plug-play-method-to-create-water-dispersible-nanoassemblies

Research

JoVE Journal

Chemistry

A 'Plug and Play' Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles

9.8K visualizações.  Simon Fraser University. Organic dye molecules and oleic acid coated upconverting nanoparticles are not water-soluble. This protocol describes a ‘plug and play’ method that enables the transfer of organic dye molecules and upconverting particles from their initial hydrophobic solvent to water. 

Vídeo: A 'Plug and Play' Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles

Analysis of Volatile and Oxidation Sensitive Compounds Using a Cold Inlet System and Electron Impact Mass Spectrometry

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The analysis of volatile and oxidation sensitive compounds by mass spectrometry is not easily achieved, as all state-of-the-art mass spectrometric methods require at least one sample preparation step, e.g., dissolution and dilution of the analyte (electrospray ionization), co-crystallization of the analyte with a matrix compound (matrix-assisted laser desorption/ionization), or transfer of the prepared samples into the ionization source of the mass spectrometer, to be conducted under atmospheric conditions. Here, the use of a sample inlet system is described which enables the analysis of volatile metal organyls, silanes, and phosphanes using a sector field mass spectrometer equipped with an electron impact ionization source. All sample preparation steps and the sample introduction into the ion source of the mass spectrometer take place either under air-free conditions or under vacuum, enabling the analysis of compounds highly susceptible to oxidation. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes, which have to be handled using inert conditions, such as the Schlenk technique. The principle of operation is presented in this video.

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The presented technique is especially of interest for inorganic chemists, working with metal organyls, silanes, or phosphanes which have to be handled using inert conditions, such as the Schlenk technique.

Análise de compostos sensíveis voláteis e oxidação usando um sistema de frio e de entrada Electron Impact Espectrometria de Massa

This video presents a protocol for the mass spectrometrical analysis of volatile and oxidation sensitive compounds using electron impact ionization. The ...

Química

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

Síntese e caracterização de funcionalizados metal-organic frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated &#62;300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy.

We describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles via the reduction of chloroauric acid (HAuCl4) with sodium thiocyanate (NaSCN). The oligoclusters have a narrow size distribution and can be produced with a wide range of sizes and surface coats.

Um método simples para o tamanho Síntese controlada de estáveis ​​Oligoméricas Clusters de nanopartículas em condições ambientais

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

An ELISA Based Binding and Competition Method to Rapidly Determine Ligand-receptor Interactions

A comprehensive understanding of signaling pathways requires detailed knowledge regarding ligand-receptor interaction. This article describes two fast and reliable point-by-point protocols of enzyme-linked immunosorbent assays (ELISAs) for the investigation of ligand-receptor interactions: the direct ligand-receptor interaction assay (LRA) and the competition LRA. As a case study, the ELISA based analysis of the interaction between different lambda interferons (IFNLs) and the alpha subunit of their receptor (IL28RA) is presented: the direct LRA is used for the determination of dissociation constants (KD values) between receptor and IFN ligands, and the competition LRA for the determination of the inhibitory capacity of an oligopeptide, which was designed to compete with the IFNLs at their receptor binding site. Analytical steps to estimate KD and half maximal inhibitory concentration (IC50) values are described. Finally, the discussion highlights advantages and disadvantages of the presented method and how the results enable a better molecular understanding of ligand-receptor interactions.

The presented protocols describe two enzyme-linked immunosorbent assay (ELISA) based techniques for the rapid investigation of ligand-receptor interactions: The first assay allows the determination of dissociation constant between ligand and receptor. The second assay enables a rapid screening of blocking peptides for ligand-receptor interactions.

Um ELISA baseada Encadernação e Método de competição de determinar rapidamente interacções ligando-receptor

A comprehensive understanding of signaling pathways requires detailed knowledge regarding ligand-receptor interaction. This article describes two fast and ...

The Preparation and Properties of Thermo-reversibly Cross-linked Rubber Via Diels-Alder Chemistry

A method for using Diels Alder thermo-reversible chemistry as cross-linking tool for rubber products is demonstrated. In this work, a commercial ethylene-propylene rubber, grafted with maleic anhydride, is thermo-reversibly cross-linked in two steps. The pending anhydride moieties are first modified with furfurylamine to graft furan groups to the rubber backbone. These pendant furan groups are then cross-linked with a bis-maleimide via a Diels-Alder coupling reaction. Both reactions can be performed under a broad range of experimental conditions and can easily be applied on a large scale. The material properties of the resulting Diels-Alder cross-linked rubbers are similar to a peroxide-cured ethylene/propylene/diene rubber (EPDM) reference. The cross-links break at elevated temperatures (&#62; 150 &#176;C) via the retro-Diels-Alder reaction and can be reformed by thermal annealing at lower temperatures (50-70 &#176;C). Reversibility of the system was proven with infrared spectroscopy, solubility tests and mechanical properties. Recyclability of the material was also shown in a practical way, i.e., by cutting a cross-linked sample into small parts and compression molding them into new samples displaying comparable mechanical properties, which is not possible for conventionally cross-linked rubbers.

A simple two-step approach involving rubber modification and cross-linking yields fully reworkable, elastic rubber products.

A preparação e propriedades de termo-reversível reticulada Química Rubber Via Diels-Alder

A method for using Diels Alder thermo-reversible chemistry as cross-linking tool for rubber products is demonstrated. In this work, a commercial ...

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group

Here, we demonstrate a detailed protocol for the radiosynthesis of a 125I-labeled azide prosthetic group and its application to the efficient radiolabeling of DBCO-group-functionalized gold nanoparticles using a copper-free click reaction. Radioiodination of the stannylated precursor (2) was carried out by using [125I]NaI and chloramine T as an oxidant at room temperature for 15 min. After HPLC purification of the crude product, the purified 125I-labeled azide (1) was obtained with high radiochemical yield (75 &plusmn; 10%, n = 8) and excellent radiochemical purity (&gt;99%). For the synthesis of radiolabeled 13-nm-sized gold nanoparticles, the DBCO-functionalized gold nanoparticles (3) were prepared by using a thiolated polyethylene glycol polymer. A copper-free click reaction between 1 and 3 gave the 125I-labeled gold nanoparticles (4) with more than 95% of radiochemical yield as determined by radio-thin-layer chromatography (radio-TLC). These results clearly indicate that the present radiolabeling method using a strain-promoted copper-free click reaction will be useful for the efficient and convenient radiolabeling of DBCO-group-containing nanomaterials.

An Optimized Protocol for the Efficient Radiolabeling of Gold Nanoparticles by Using a 125I-labeled Azide Prosthetic Group

A detailed procedure for the synthesis of a 125I-labeled azide and the radiolabeling of dibenzocyclooctyne (DBCO)-group-conjugated, 13-nm-sized gold nanoparticles using a copper-free click reaction is described.

Um protocolo otimizado para a radiomarcação eficiente de nanopartículas de ouro usando um<sup&gt; 125</sup&gt; Marcado com Eu Azida grupo prostético

Here, we demonstrate a detailed protocol for the radiosynthesis of a 125I-labeled azide prosthetic group and its application to the efficient ...

Grafting Multiwalled Carbon Nanotubes with Polystyrene to Enable Self-Assembly and Anisotropic Patchiness

We demonstrate a straightforward protocol to graft pristine multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) chains at the sidewalls through a free-radical polymerization strategy to enable the modulation of the nanotube surface properties and produce supramolecular self-assembly of the nanostructures. First, a selective hydroxylation of the pristine nanotubes through a biphasic catalytically mediated oxidation reaction creates superficially distributed reactive sites at the sidewalls. The latter reactive sites are subsequently modified with methacrylic moieties using a silylated methacrylic precursor to create polymerizable sites. Those polymerizable groups can address further polymerization of styrene to produce a hybrid nanomaterial containing PS chains grafted to the nanotube sidewalls. The polymer-graft content, amount of silylated methacrylic moieties introduced and hydroxylation modification of the nanotubes are identified and quantified by Thermogravimetric Analysis (TGA). The presence of reactive functional groups hydroxyl and silylated methacrylate are confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). Polystyrene-grafted carbon nanotube solutions in tetrahydrofuran (THF) provide wall-to-wall collinearly self-assembled nanotubes when cast samples are analyzed by transmission electron microscopy (TEM). Those self-assemblies are not obtained when suitable blanks are similarly cast from analogous solutions containing non-grafted counterparts. Therefore, this method enables the modification of the nanotube anisotropic patchiness at the sidewalls which results into spontaneous auto-organization at the nanoscale.

A procedure for the synthesis of polystyrene-grafted multiwalled carbon nanotubes using successive chemical modification steps to selectively introduce the polymer chains to the sidewalls and their self-assembly via anisotropic patchiness is presented.

Enxertia de nanotubos de carbono de Multiwalled com poliestireno para habilitar auto-montagem e anisotrópica Patchiness

We demonstrate a straightforward protocol to graft pristine multiwalled carbon nanotubes (MWCNTs) with polystyrene (PS) chains at the sidewalls through a ...

Time-resolved Photophysical Characterization of Triplet-harvesting Organic Compounds at an Oxygen-free Environment Using an iCCD Camera

Here, we present a sensible method of the acquisition and analysis of time-resolved photoluminescence using an ultrafast iCCD camera. This system enables the acquisition of photoluminescence spectra covering the time regime from nanoseconds up to 0.1 s. This enables us to follow the changes in the intensity (decay) and emission of the spectra over time. Using this method, it is possible to study diverse photophysical phenomena, such as the emission of phosphorescence, and the contributions of prompt and delayed fluorescence in molecules showing thermally activated delayed fluorescence (TADF). Remarkably, all spectra and decays are obtained in a single experiment. This can be done for solids (thin film, powder, crystal) and liquid samples, where the only limitations are the spectral sensitivity of the camera and the excitation wavelength (532 nm, 355 nm, 337 nm, and 266 nm). This technique is, thus, very important when investigating the excited state dynamics in organic emitters for their application in organic light-emitting diodes and other areas where triplet harvesting is of paramount importance. Since triplet states are strongly quenched by oxygen, emitters with efficient TADF luminescence, or those showing room temperature phosphorescence (RTP), must be correctly prepared in order to remove any dissolved oxygen from solutions and films. Otherwise, no long-lived emission will be observed. The method of degassing solid samples as presented in this work is basic and simple, but the degassing of liquid samples creates additional difficulties and is particularly interesting. A method of minimizing solvent loss and changing the sample concentration, while still enabling to remove oxygen in a very efficient and a repeatable manner, is presented in this work.

Here, we present a method of the spectroscopic characterization of organic molecules by means of time-resolved photoluminescence spectroscopy on the nanosecond-to-millisecond timescale in oxygen-free conditions. Methods to efficiently remove oxygen from the samples and, thus, limit luminescence quenching are also described.

Tempo-resolvido compostos orgânicos de Photophysical caracterização dos Triplet-colheita em um livre de oxigênio ambiente usando uma câmera de iCCD

Here, we present a sensible method of the acquisition and analysis of time-resolved photoluminescence using an ultrafast iCCD camera. This system enables ...

Raman and IR Spectroelectrochemical Methods as Tools to Analyze Conjugated Organic Compounds

In the presented work, two spectroelectrochemical techniques are discussed as tools for the analysis of the structural changes occurring in the molecule on the vibrational level of energy. Raman and IR spectroelectrochemistry can be used for advanced characterization of the structural changes in the organic electroactive compounds. Here, the step-by-step analysis by means of Raman and IR spectroelectrochemistry is shown. Raman and IR spectroelectrochemical techniques provide complementary information about structural changes occurring during an electrochemical process, i.e. allows for the investigation of redox processes and their products. The examples of IR and Raman spectroelectrochemical analysis are presented, in which the products of the redox reactions, both in solution and solid state, are identified.

A protocol of step-by-step Raman and IR spectroelectrochemical analysis is presented.

Raman e IR Spectroelectrochemical métodos como ferramentas para analisar compostos orgânicos conjugados

In the presented work, two spectroelectrochemical techniques are discussed as tools for the analysis of the structural changes occurring in the molecule ...

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, allowing for the synthesis of isotactic poly(&#945;-hydroxy acids) with expected molecular weights (&#62;140 kDa) and narrow molecular weight distributions (Mw/Mn &#60; 1.1). This ring-opening polymerization is mediated by Ni and Zn complexes in the presence of an alcohol initiator and a photoredox Ir catalyst, irradiated by a blue LED (400 - 500 nm). The polymerization is performed at a low temperature (-15 &#176;C) to avoid undesired side reactions. The complete monomer consumption can be achieved within 4 - 8 hours, providing a polymer close to the expected molecular weight with narrow molecular weight distribution. The resulted number-average molecular weight shows a linear correlation with the degree of polymerization up to 1000. The homodecoupling 1H NMR study confirms that the obtained polymer is isotactic without epimerization. This polymerization reported herein offers a strategy for achieving rapid, controlled O-carboxyanhydrides polymerization to prepare stereoregular poly(&#945;-hydroxy acids) and its copolymers bearing various functional side-chain groups.

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

A protocol for the controlled photoredox ring-opening polymerization of O-carboxyanhydrides mediated by Ni/Zn complexes is presented.

Controlado por polimerização de anel de abertura Photoredox do - Carboxyanhydrides, mediada por complexos de Ni/Zn

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, ...

Um método 'Plug and Play' para criar Nanoassemblies dispersáveis ​​em água contendo um polímero anfifílicas, corantes orgânicos e Upconverting Nanopartículas

Um método 'Plug and Play' para criar Nanoassemblies dispersáveis em água contendo um polímero anfifílicas, corantes orgânicos e Upconverting Nanopartículas