Yazarlar minnetle bu projenin verdikleri destek için Missouri State Üniversitesi Kimya Bölümü ve Lisansüstü Koleji kabul. Biz de onların transmisyon elektron mikroskobu ve karbon kaplı ızgaraları kullanımı için Kanser Araştırma Frederick Ulusal Laboratuvarı&#39;nda Elektron Mikroskopi Laboratuvarı kabul.

Indiyum fosfit / Çinko Sülfür (InP / ZnS) Kuantum Noktalarının 1. Sentezi <ol><li> Indiyum fosfit (InP) Kuantum Nokta Çekirdek Sentezi <ol><li> 12 inç kondansatör ile 100 ml&#39;lik bir yuvarlak tabanlı, 3 boyunlu, şişeyi monte edin. 30 mi oleilamin (OLA), 0.398 gr indiyum (III) klorür (Dahil 3), 0.245 g çinko (II) klorid (ZnCl2) ilave edilir ve 1 saat süre ile bir vakum kullanılarak, oda sıcaklığında tahliye sırasında karıştırıldı. Çözelti beyaz bir çökelti ile renksiz görünmelidir. </li><li> bir termokupl ve oransal-entegral-türev (PID) sıcaklık kontrol cihazı, bir ısıtma gömleği kullanılarak, 120 ° C&#39;ye kadar çözeltinin sıcaklığı artar. Çekirdek büyümesini etkileyebilir düşük kaynama noktalı yabancı maddelerin ayrılması için 20 dakika boyunca vakum altında çözelti tahliye edin. Not: bir ısıtıcı kullanılarak bir kum banyosu ve termometre kullanmak mümkündür PID reaksiyon ürünlerinin muntazamlığı ve tekrar üretilebilirliği arttığı gözlenmektedir. </li><li> Atıl gaz altında (örnN, 2), çözelti geri akışa ve 15 dakika boyunca 220 ° C&#39;ye kadar sıcaklık artışı. Dahil olmak 3 ve ZnCl2 tamamen açık sarı bir çözelti elde çözülür. Sıcaklık, 10 dakika dengelenmesine izin verin. </li><li> tek kullanımlık, 3 ml plastik şırınga ve 4 inç, azot gazı ile 22 G iğne temizleyin. Şırınga kullanarak hızlı bir şekilde dahil olmak 3 çözeltisine, 0.5 ml tris (dimetilamino) fosfin (TDMAP) sağlar. Çözelti sıcaklığı biraz azalmakta ve 220 ° C&#39;ye kadar döner. şeffaf gelen çözüm değişiklikleri, siyah, opak sarı soluk. </li><li> Sıcaklık 200 ° C&#39;ye altına inene kadar 9.5 dakika sonra, ısıtma mantosu reaksiyon şişesi çıkarın. InP çekirdek bütünlüğünü korumak için, adım 1.2.1 ZnS kaplama doğrudan geçin. </li></ol></li><li> Çinko Sülfür (ZnS) Kuantum Nokta Kabuklar sentezi <ol><li> bir ısıtma gömleği adım 1.1.5 reaksiyon şişesi yerleştirin ve t stabilize200 ° C de emperature. Yavaş yavaş InP QD&#39;lerin içeren çözeltiye 15 saniye boyunca 3.58 g dodekantiol (DDT) ilave edin. Çözelti 1 saat süre ile reaksiyona girmesine izin verir. Not: ZnS kabuk kalınlığı artan ya da kademesi 1.2.4 ilave Çinko stearat miktarının azaltılmasıyla değiştirilebilir. Adımlar 1.1.1 ve 1.2.1 ZnCI2 miktarını ya da dodekanetiyol değiştirilmesi önemli ölçüde reaksiyon kinetiği değiştirerek QDS kalitesini etkileyebilir. <ol><li> Daha sonra, ısıtma mantosu reaksiyon şişesi çıkarın ve çözelti, yaklaşık olarak 60 ° C&#39;ye soğumasını sağlayın. </li></ol></li><li> InP / ZnS solüsyonu ~ ulaştığında 60 ° C, 10 mi heksan ilave bir 50 ml polipropilen santrifüj tüpüne yaklaşık 45 ml tüm çözeltisini. girmemiş katı öncüllerini ortadan kaldırmak için numune (10 dakika 3.000 xg) santrifüj. </li><li> Dikkatle (santrifüj 3000 x çözelti, 250 ml&#39;lik bir polipropilen santrifüj şişesine süpernatan transferi 200 ml aseton ekleyin ve10 dakika) g InP / ZnS QD&#39;lerin çökeltildi. Gerekli rotor / aksesuarları ile bir santrifüj mevcut değilse, bu hacmi de santrifüj dört 50 ml tüpler içine eşit bölünebilir. Süpernatant boşaltacaktır ve asetonun çıkarılması için azot gazı ile iyice QD pelet kurutulur. </li><li> Sonikasyon kullanılarak 20 mi Ola QD&#39;lerin süspanse bir 50 ml&#39;lik yuvarlak tabanlı, 3-boyunlu şişe, ihtiva eden 0.474 g çinko stearat ve karışmaya aktarın. Oda sıcaklığında 20 dakika boyunca vakum altında çözelti tahliye edin. </li><li> azot gazı altında, 180 ° C sıcaklık artışı ve reaksiyon, 3 saat devam etmesine izin verir. Bu reaksiyon sırasında meydana gelen reaksiyon çözeltisine, herhangi bir göze çarpan optik bir değişiklik olmakla birlikte, çinko stearat eklenmesi ve böylece QDS 12. yüzey pasivasyonu geliştirerek QY artan ZnS kabuk kalınlığı artar. Reaksiyon tamamlandıktan sonra, ısıtma mantosu balonun çıkarın ve çözelti, yaklaşık olarak 60 ° C&#39;ye soğumasını sağlayın. </li><li> InP / ZnS soluti kezulaştığında üzerinde ~ 60 ° C, 20 mL heksanlar ekleyin ve 50 ml polipropilen santrifüj tüpüne aktarılır. reaksiyona girmemiş çinko stearat kaldırmak için numune (10 dakika 3.000 xg) santrifüj. </li><li> Dikkatle, 250 ml&#39;lik bir polipropilen santrifüj şişesine süpernatantı transfer InP / ZnS QD&#39;lerin çökeltmek için 200 ml aseton ve santrifüj çözeltisi (10 dakika boyunca 3,000 x g) ekleyin. Süpernatantı dikkatlice süzün ve asetonu uzaklaştırmak için azot gazı ile iyice kurulayın. </li><li> 30 ml heksan içinde InP / ZnS QD pelet çözülür. Vortex ve tam dağılmayı sağlamak için kısaca çözüm sonikasyon. </li><li> Tekrarlama arıtma aşırı organik ligandların tam kaldırılmasını sağlamak için 1.2.6-1.2.8 iki kez daha yineleyin. amfifilik polimer ve adım 1.2 &#39;de QD arasındaki etkileşimler aşırı ligandlar varlığında tehlikeye girebilir. </li><li> Xie tarafından ayrıntılı hesaplamalar, vd. 16, UV-Vis Spektroskopisi kullanarak sentezlenen InP / ZnS QDS büyüklüğünü ve konsantrasyonunu belirlemek. <br/&gt; Not: Bu analiz için önemli spektral karakteristik absorpsiyon tepe omuz olduğunu. Bu omuz maksimum dalga boyu ve absorbans değerleri sırasıyla, boyut ve QDS konsantrasyonunu hesaplamak için kullanılır. Bu reaksiyon tipik olarak 600 nm&#39;de emisyon tepe noktası ile yaklaşık 5 umol QDS verir. Farklı renklerde QD&#39;lerin sentezlemek için, reaksiyon süresi ve / veya sıcaklık değiştirilebilir. Daha uzun bir reaksiyon süresi ve / veya kırmızı-kaydırılmış emisyon tepe çözüm sonuçlarının daha yüksek ısı. Örneğin, 10 dakika 240 ° C&#39;ye kadar, reaksiyon sıcaklığı artmaktadır ve bakımını reaksiyon süresi, 680 nm, maksimum emisyon tepe QDS neden olur. Benzer bir şekilde, 2 dakika, reaksiyon süresini azaltmak ve 470 nm maksimum emisyon tepe QDS neden olur kullanılan çinko klorür katlama. Bu InP / ZnS QDS inert bir gaz altında, karanlıkta 4 ° C&#39;de en az bir ay boyunca stabildir. </li></ol></li></ol> 2. Suamfifilik polimer kullanılarak InP / ZnS Kuantum Nokta hidrolizi <ol><li> su Çözme <ol><li> Aşama 1.2.10 arasında InP / ZnS QD&#39;lerin kullanılarak, 1 uM QDS 1 ml elde etmek üzere heksan ile QDS bir kısmını seyreltin. <ol><li> bir santrifüj tüpü içinde, her bir tüp içine 0.25 ml InP / ZnS QD&#39;lerin aktarın. Santrifüj tüp ve santrifüj (10 dakika boyunca 3,000 x g), 1 ml aseton veya metanol ekleyin. Süpernatantı dikkatlice çıkarın ve 1 ml tetrahidrofuran (THF) içinde, her bir çökelti çözülür. </li><li> 100 ml&#39;lik bir yuvarlak tabanlı şişe içine THF InP / ZnS QD&#39;lerin aktarın ve 16 ml THF ile seyreltilir. Çözeltideki parçaların sayısını azaltmak 5-10 dakika süreyle QD&#39;lerin sonikasyon. </li></ol></li><li> 10 mi moleküler sınıf su içinde 30 mg poli (maleik andhydride- Alt -1 oktadesen), 3- (dimetilamino) -1-propilamin (PMAL-d) içinde çözülür. Çözelti berrak hale gelene kadar su banyosu sonikasyon ya da hafif karıştırma işlemi tamamen polimer erimesi için yeterlidir.girdap veya sert karıştırma kullanımı QD polimerin etkileşimini engelleyen birçok kabarcık üretebilir. Yuvarlak THF InP / ZnS QD&#39;lerin ihtiva dipli bir şişeye 100 ml, 10 ml, polimer solüsyonu ekleyin. </li><li> Bir dönen buharlaştıncı kullanarak QD / polimer çözeltisinden THF buharlaşır. polimer ve QD arasındaki etkileşimi kolaylaştırmak için buharlaştırma sırasında bir buz banyosu içine yerleştirilir. Vakum gücüne bağlı olarak, en fazla 10 dakika sonra, THF buharlaştırılmakta ve çözelti bulanık görünür. <ol><li> Çözelti, 10 ml kadar buharlaştırılır sonra, döner bir buharlaştırıcı şişeden çıkarın ve 30 ml moleküler sınıf su ilave edilir. Döner bir buharlaştırıcı için şişeyi geri dönün ve 2 ml kadar buharlaşmaya devam etmektedir. Bu son buharlaşma adım saatler sürebilir; buz banyosu korunmasını sağlar. </li></ol></li><li> bir pipet, yuvarlak dipli bir şişeye su çözünür InP / ZnS QD&#39;lerin çıkarın. 0.1 um naylon sy bağlanmış bir 3 ml&#39;lik plastik bir şırınga kullanılarak QD solüsyonu Filtreringe 5 ml santrifüj tüpü içine filtre. </li><li> 20.000 MWCO membran diyaliz ünitesine QD&#39;lerin yerleştirin ve aşırı polimer çıkarmak için 0.05 M borat tamponu pH 8.5 karşı dialyze. (PH değeri, bu tampon çözeltisi olmak için 8.5 olana kadar yavaş yavaş, kuvvetli bir şekilde karıştırılarak, 0.05 M borik asit 0.05 M sodyum tetraborat dekahidratı ekleyin.), Bir vakum konsantratör kullanılarak, 1 ml borat tampon maddesi içinde QD&#39;lerin konsantre edilir. </li><li> depolama için, Parafilm ile sızdırmazlık önce azot gazı ile çözüm temizlemek. suda çözünür InP / ZnS QDS karanlıkta 4 ° C&#39;de en az 4 ay boyunca stabildir. </li></ol></li></ol>

<ol>
	<li>Alivisatos, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Semicondictor+clusters,+nanocrystals,+and+quantum+dots.">Semicondictor clusters, nanocrystals, and quantum dots.</a> Science. 271 (5251), 933-937 (1996).</li><li>Michalet, X., 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=Quantum+dots+for+live+cells,+in+vivo+imaging,+and+diagnostics.">Quantum dots for live cells, in vivo imaging, and diagnostics.</a> Science. 307 (5709), 538-544 (2005).</li><li>Jaiswal, J. K., Mattoussi, H., Mauro, J. M., Simon, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+multiple+color+imaging+of+live+cells+using+quantum+dot+bioconjugates.">Long-term multiple color imaging of live cells using quantum dot bioconjugates.</a> Nat. Biotechnol. 21 (1), 47-51 (2009).</li><li>Deerinck, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+application+of+fluorescent+quantum+dots+to+confocal,+multiphoton,+and+electron+microscopic+imaging.">The application of fluorescent quantum dots to confocal, multiphoton, and electron microscopic imaging.</a> Toxicol. Pathol. 36 (1), 112-116 (2008).</li><li>Smith, A. M., Duan, H., Mohs, A. M., Nie, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioconjugated+quantum+dots+for+in+vivo+molecular+and+cellular+imaging.">Bioconjugated quantum dots for in vivo molecular and cellular imaging.</a> Adv. Drug Deliv. Rev. 60 (11), 1226-1240 (2008).</li><li>Jamieson, 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=Biological+applications+of+quantum+dots.">Biological applications of quantum dots.</a> Biomaterials. 28 (31), 4717-4732 (2007).</li><li>Lidke, D. S., Arndt-Jovin, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+takes+a+quantum+leap.">Imaging takes a quantum leap.</a> Physiology. 19, 322-325 (2004).</li><li>Fichter, K. M., Flajolet, M., Greengard, P., Vu, T. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetics+of+G-protein-couple+receptor+endosomal+trafficking+pathways+revealed+by+single+quantum+dots.">Kinetics of G-protein-couple receptor endosomal trafficking pathways revealed by single quantum dots.</a> Proc. Natl. Acad. Sci. U.S.A. 107 (43), 18658-18663 (2010).</li><li>Smith, A. M., Ruan, G., Rhyner, M. N., Nie, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engineering+luminescent+quantum+dots+for+in+vitro+molecular+and+cellular+imaging.">Engineering luminescent quantum dots for in vitro molecular and cellular imaging.</a> Ann. Biomed. Eng. 34 (1), 3-14 (2006).</li><li>Derfus, A. M., Chan, W. C. W., Bhatia, S. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probing+the+cytotoxicity+of+semiconductor+quantum+dots.">Probing the cytotoxicity of semiconductor quantum dots.</a> Nano Lett. 4 (1), 11-18 (2004).</li><li>Brunetti, 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=InP/ZnS+as+a+safer+alternative+to+CdSe/ZnS+core/shell+quantum+dots:+in+vitro+and+in+vivo+toxicity+assessment.">InP/ZnS as a safer alternative to CdSe/ZnS core/shell quantum dots: in vitro and in vivo toxicity assessment.</a> Nanoscale. 5 (1), 307-317 (2013).</li><li>Song, W., 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=Amine-derived+synthetic+approach+to+color-tunable+InP/ZnS+quantum+dots+with+high+fluorescent+qualities.">Amine-derived synthetic approach to color-tunable InP/ZnS quantum dots with high fluorescent qualities.</a> J. Nanopart. Res. 15 (1750), (1750).</li><li>Dabbousi, B. O., 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=(CdSe)ZnS+core-shell+quantum+dots:+Synthesis+and+characterization+of+a+size+series+of+highly+luminescent+nanocrystallites.">(CdSe)ZnS core-shell quantum dots: Synthesis and characterization of a size series of highly luminescent nanocrystallites.</a> J. Phys. Chem. B. 101 (46), 9463-9475 (1997).</li><li>Micic, O. I., Curtis, C. J., Jones, K. M., Sprague, J. R., Nozik, A. J. <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+InP+quantum+dots.">Synthesis and characterization of InP quantum dots.</a> J. Phys. Chem. 98 (19), 4966-4969 (1994).</li><li>Qi, L., Gao, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantum+dot-amphipol+nanocomplex+for+intracellular+delivery+and+realtime+imaging+of+siRNA.">Quantum dot-amphipol nanocomplex for intracellular delivery and realtime imaging of siRNA.</a> ACS Nano. 2 (7), 1403-1410 (2008).</li><li>Xie, R., Zheng, L., Peng, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nucleation+kinetics+vs+chemical+kinetics+in+the+initial+formation+of+semiconductor+nanocrystals.">Nucleation kinetics vs chemical kinetics in the initial formation of semiconductor nanocrystals.</a> J. Am. Chem. Soc. 131 (42), 15457-15466 (2009).</li><li>Williams, A. T. R., Winfield, S. A., Miller, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relative+fluorescence+quantum+yields+using+a+computer-controlled+luminescence+spectrometer.">Relative fluorescence quantum yields using a computer-controlled luminescence spectrometer.</a> Analyst. 108, 1067-1071 (1983).</li><li>Schindelin, 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=Fiji:+An+open-source+platform+for+biological-image+analysis.">Fiji: An open-source platform for biological-image analysis.</a> Nat. Methods. 9 (7), 676-682 (2012).</li><li>Schnieder, C. A., Rasband, W. S., Eliceiri, K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NIH+image+to+ImageJ:+25+years+of+image+analysis.">NIH image to ImageJ: 25 years of image analysis.</a> Nat. Methods. 9, 671-675 (2012).</li><li>Jin, Y., Kannan, S., Wu, M., Zhao, J. X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxicity+of+luminescent+silica+nanoparticles+to+living+cells.">Toxicity of luminescent silica nanoparticles to living cells.</a> Chem. Res. Toxicol. 20 (8), 1126-1133 (2007).</li><li>Corazzari, I., Gilardino, A., Dalmazzo, S., Fubini, B., Lovisolo, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Localization+of+CdSe/ZnS+quantum+dots+in+the+lysosomal+acidic+compartment+of+cultured+neurons+and+its+impact+on+viability:+potential+role+of+ion+release.">Localization of CdSe/ZnS quantum dots in the lysosomal acidic compartment of cultured neurons and its impact on viability: potential role of ion release.</a> Toxicol. In Vitro. 27 (2), 752-759 (2013).</li><li>Pons, T., Uyeda, H. T., Medintz, I., Mattoussi, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrodynamic+dimensions,+electrophoretic+mobility,+and+stability+of+hydrophilic+quantum+dots.">Hydrodynamic dimensions, electrophoretic mobility, and stability of hydrophilic quantum dots.</a> J. Phys. Chem. B. 110 (41), 20308-20316 (2006).</li><li>Durisic, N., Wiseman, P., Grutter, P., Heyes, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+common+mechanism+underlies+the+dark+fraction+formation+and+fluorescence+blinking+of+quantum+dots.">A common mechanism underlies the dark fraction formation and fluorescence blinking of quantum dots.</a> ACS Nano. 3 (5), 1167-1175 (2009).</li><li>Vermehren-Schmaedick, 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=Heterogeneous+intracellular+trafficking+dynamics+of+brain-derived+neurotropic+factor+complexes+in+the+neuronal+soma+revealed+by+single+quantum+dot+tracking.">Heterogeneous intracellular trafficking dynamics of brain-derived neurotropic factor complexes in the neuronal soma revealed by single quantum dot tracking.</a> PLoS ONE. 9 (4), e95113 (2014).</li></ol>

Yazarlar ifşa hiçbir şey yok.

Bu protokol, bir çok biyolojik sistemlerde kullanılabilir yüksek floresan InP / ZnS QDS sentezini göstermektedir. Burada sentezlenen QD ürünleri için diğer daha önce tarif edilen sentezlerin 12 ile karşılaştırılabilir 73 nm (Şekil 1) &#39;in bir FWHM, 600 nm&#39;de odaklanmış olan tek bir floresans emisyon tepe sergiledi. Tepki süresi ve reaksiyon sıcaklığı QD sentez kalitesi ve tekrarlanabilirlik üzerindeki derin etkisi nedeniyle son derece önemli adımlardır. Suda ?...

A correction was made to: <a href="http://www.jove.com/video/53684/synthesis-cd-free-inpzns-quantum-dots-suitable-for-biomedical" target="_blank">Synthesis of Cd-free InP/ZnS Quantum Dots Suitable for Biomedical Applications</a>. There was an error with an author's given name. The author's name was corrected to:
Katye M. Fichter
from:
Kathryn M. Fichter

A correction was made to: <a href="http://www.jove.com/video/53684/synthesis-cd-free-inpzns-quantum-dots-suitable-for-biomedical" target="_blank">Synthesis of Cd-free InP/ZnS Quantum Dots Suitable for Biomedical Applications</a>.

Erratum: Synthesis of Cd-free InP/ZnS Quantum Dots Suitable for Biomedical Applications

Kuantum nokta (QD&#39;lerin) ışık 1 ile ışınlanmış zaman floresan özellikleri sergileyen nanokristaller yarıiletken vardır. Nedeniyle kendi küçük birçok büyük biyomoleküllerin benzer büyüklükte (2-5 nm) ve biofunctionalization kolaylığı, QD&#39;lerin biyomedikal uygulamaları için son derece cazip bir araçtır. Bunlar, biyolojik etiketleme kullanım bulmuşlardır, diğer kullanımlar 2-8 arasındaki tek-molekül canlı hücre görüntüleme, ilaç verme, in vivo görüntüleme, patojen tespiti ve hücre takibi. CD tabanlı QDS en çok nedeniyle şiddetli floresan ve dar emisyon tepe genişlikleri 9 biyomedikal uygulamalarda kullanılmaktadır. Ancak, endişeler sebebiyle Cd potansiyel toksisitesi ortaya atılan 2+ Nanopartikülün bozulması yoluyla serbest bırakılabilir 10 iyonlar. Birçok flüoresan özellikleri korumak için en son, InP tabanlı QDS CD tabanlı QDS alternatif olarak araştırılmıştırve QD&#39;lerin Cd-tabanlı ve 11 daha biyouyumlu olabilir. CD tabanlı QDS sadece 48 saat sonra 11, 10 pM kadar düşük konsantrasyonlarda, in vitro deneylerde InP tabanlı QDS önemli ölçüde daha fazla toksik olduğu tespit edilmiştir. QDS floresans emisyon renk boyut ayarlanabilir 1&#39;dir. Bu QD boyutu arttıkça, floresans emisyon kırmızı kaydırılır vardır. QD ürün boyutu ve boyut dispersitesi reaksiyon 12 boyunca sıcaklık, reaksiyon süresi, ve ön-madde konsantrasyonu, koşullarını değiştirerek değiştirilebilir. InP QDS emisyon tepe tipik olarak daha geniş ve CD tabanlı QDS daha az yoğun olduğu birlikte, InP QDS spektral çakışmasını önlemek için tasarlanmış bir renk büyük bir çeşitlilik içinde yapılır ve en çok biyomedikal uygulamalar 12 yeterince yoğundur edilebilir. Bu protokol, ayrıntılı bir sentez 600 nm&#39;de odaklanmış olan kırmızı salma tepe QD&#39;lerin verir. Birkaç adım af alınırQD çekirdeklerinin ter sentezi QDS optik bütünlüğünü korumak ve biyolojik uygulamalar için uyumlu hale getirmek için. QD iç yüzeyi söndürülmesi neden olabilir oksitleme veya yüzey kusurları korunmalıdır; Bu nedenle, bir ZnS kabuğu InP / ZnS (çekirdek / kabuk) 13 QDS üretmek için iç kısım üzerine kaplanır. Bu kaplama, QD ürünün fotolüminesans korumak için gösterilmiştir. InP QD sentezi sırasında çinko iyonlarının bulunması, yüzey kusurları, ve düşüş büyüklüğü dağılımı 12 sınırlamak için gösterilmiştir. Hatta, reaksiyon ortamı içinde Zn2 + varlığında ile InZnP sentezi 12 yüksek olası değildir. Kaplamadan sonra, elde edilen InP / ZnS QDS örneğin trioctylphosphine oksit (TOPO) ya da oleilamin 12,14 hidrofobik ligandlar içinde kaplanır. Amfifilik polimerin suda çözünürlüğü 15 vermek için QD yüzeye hidrofobik ligandlar olarak toplu su molekülleri ile etkileşime girebilir. karbo ile amfifilik polimerlerxylate kimyasal gruplar ayrıca QD&#39;lerin işlevselleştirilmesi &quot;Kimyasal kulp&quot; olarak da kullanılabilir. Bu protokol, çok yoğun floresan emisyonu ve nispeten küçük boyutu yayılganlığı ile sentezi ve suda çözünür InP / ZnS QDS fonksiyonalizasyonu göstermektedir. Bu QDS potansiyel yaygın olarak kullanılan CdSe / ZnS QDS daha az toksiktir. Burada InP / ZnS QDS sentezi biyomedikal uygulamalar için Cd-tabanlı QDS için pratik bir alternatif sunuyor.

<table><tbody><tr><td>Oleylamine</td><td>Acros</td><td>129540010</td><td></td></tr><tr><td>Zinc(II) chloride</td><td>Sigma</td><td>030-003-00-2</td><td></td></tr><tr><td>Indium(III) chloride</td><td>Chem-Impex</td><td>24560</td><td></td></tr><tr><td>Tris(dimethylamino)phosphine</td><td>Encompass</td><td>50-901-10500</td><td></td></tr><tr><td>1-dodecanethiol</td><td>Acros</td><td>117625000</td><td></td></tr><tr><td>Hexanes</td><td>Fisher Sci</td><td>H292-4</td><td></td></tr><tr><td>Acetone</td><td>TransChemical</td><td>UN 1090</td><td></td></tr><tr><td>Zinc Stearate</td><td>Aldrich Chem</td><td>307564-1KG</td><td></td></tr><tr><td>Tetrahydrofuran</td><td>Acros</td><td>34845-0010</td><td></td></tr><tr><td>Molecular Water</td><td>Fisher Sci</td><td>BP2470-1</td><td></td></tr><tr><td>Poly(maleic anhyrdride-&lt;em&gt;alt&lt;/em&gt;-1-tetradecene), 3-(dimethylamino)-1-propylamine derivative</td><td>Sigma</td><td>90771-1G</td><td></td></tr><tr><td>Boric acid</td><td>Fisher Sci</td><td>BP168-500</td><td></td></tr><tr><td>Sodium Tetraborate Decahydrate</td><td>Fisher Sci</td><td>BP175-500</td><td></td></tr><tr><td>Rhodamine B</td><td>Aldrich Chem</td><td>R95-3</td><td></td></tr><tr><td>Nitrogen gas</td><td>Airgas</td><td>UN1066</td><td></td></tr><tr><td>Trypan blue</td><td>Thermo Sci</td><td>SV30084.01</td><td></td></tr><tr><td>3 ml plastic Luer-lock syringe</td><td>BD</td><td>309657</td><td></td></tr><tr><td>Luer-lock Needle</td><td>Air-Tite</td><td>8300014471</td><td>4 inch, 22 gauge</td></tr><tr><td>50 ml polypropyene centrifuge tube</td><td>Falcon</td><td>352098</td><td></td></tr><tr><td>250 ml centrifuge bottle</td><td>Thermo Sci</td><td>05-562-23</td><td>Nalgene PPCO</td></tr><tr><td>5 ml centrifuge tubes</td><td>Argos-Tech</td><td>T2076</td><td></td></tr><tr><td>1.5 ml microcentrifuge tubes</td><td>Bio Plas</td><td>4150</td><td></td></tr><tr><td>0.1 &amp;mu;m Syringe filter</td><td>Whatman</td><td>6786-1301</td><td>Puradisc 13 mm nylon filter</td></tr><tr><td>Slide-A-Lyzer MINI Dialysis Unit</td><td>Thermo Sci</td><td>69590</td><td>20,000 MWCO</td></tr><tr><td>Rotary Evaporator</td><td>Heidolph</td><td></td><td></td></tr><tr><td>Centrifuge 5072</td><td>Eppendorf</td><td></td><td>Swinging Bucket with 50&amp;nbsp;ml tube adapters</td></tr><tr><td>Lambda 650 UV/VIS Spectrometer</td><td>Perkin Elmer</td><td></td><td>UV-Vis Spectrophotometer</td></tr><tr><td>LS 55 Fluorescence Spectrometer</td><td>Perkin Elmer</td><td></td><td>Fluorometer</td></tr><tr><td>Axio Observer.A1</td><td>Zeiss</td><td></td><td>epifluorescence microscope</td></tr><tr><td>AxioCam MRm</td><td>Zeiss</td><td></td><td>CCD Camera</td></tr><tr><td>Tecnai TF20 Microscope</td><td>FEI</td><td></td><td>Transmisison Electron Miscroscope</td></tr><tr><td>TEM Eagle CCD</td><td>FEI</td><td></td><td>TEM CCD Camera</td></tr><tr><td>NanoBrook Omni DLS</td><td>Brookhaven</td><td></td><td>Dynamic Light Scattering Instrument</td></tr></tbody></table>

synthesis of cd-free inp/zns quantum dots suitable for biomedical applications

Fluorescent nanocrystals, specifically quantum dots, have been a useful tool for many biomedical applications. For successful use in biological systems, quantum dots should be highly fluorescent and small/monodisperse in size. While commonly used cadmium-based quantum dots possess these qualities, they are potentially toxic due to the possible release of Cd2+ ions through nanoparticle degradation. Indium-based quantum dots, specifically InP/ZnS, have recently been explored as a viable alternative to cadmium-based quantum dots due to their relatively similar fluorescence characteristics and size. The synthesis presented here uses standard hot-injection techniques for effective nanoparticle growth; however, nanoparticle properties such as size, emission wavelength, and emission intensity can drastically change due to small changes in the reaction conditions. Therefore, reaction conditions such temperature, reaction duration, and precursor concentration should be maintained precisely to yield reproducible products. Because quantum dots are not inherently soluble in aqueous solutions, they must also undergo surface modification to impart solubility in water. In this protocol, an amphiphilic polymer is used to interact with both hydrophobic ligands on the quantum dot surface and bulk solvent water molecules. Here, a detailed protocol is provided for the synthesis of highly fluorescent InP/ZnS quantum dots that are suitable for use in biomedical applications.

kaplanmamış InP çekirdekler gözle önemli görünür floresan göstermek yok. Ancak, InP / ZnS (çekirdek / kabuk) kuantum noktaları, UV ışınlama altında göz ile parlak floresan görünür. InP / ZnS QDS flüoresansı, flüoresans spektroskopisi ile karakterize edilmiştir. Heksan içinde QDS floresan spektrumu 73 nm yarı maksimum (FWHM) tam bir genişliğe sahip 600 nm&#39;de ortalanmış bir majör tepe gösterir mil 533 uyarıldığında (Şekil 1). <strong...

Watch this Scientific Journal Video about Synthesis of Cd-free InP/ZnS Quantum Dots Suitable for Biomedical Applications at JoVE.com

Synthesis of Cd-free InP/ZnS Quantum Dots Suitable for Biomedical Applications

In this protocol, the synthesis of Cd-free InP/ZnS quantum dots (QDs) is detailed. InP-based QDs are gaining popularity due to the toxicity of Cd2+ ions that may be released through nanoparticle degradation. After synthesis, QDs are solubilized in water using an amphiphilic polymer for use in biomedical applications.

Biyomedikal Uygulamalar için uygundur InP / ZnS Kuantum Noktaları Cd-serbest sentezi

Fluorescent nanocrystals, specifically quantum dots, have been a useful tool for many biomedical applications. For successful use in biological systems, ...

synthesis-cd-free-inpzns-quantum-dots-suitable-for-biomedical

Research

JoVE Journal

Chemistry

13.6K Görüntüleme.  Missouri State University. In this protocol, the synthesis of Cd-free InP/ZnS quantum dots (QDs) is detailed. InP-based QDs are gaining popularity due to the toxicity of Cd2+ ions that may be released through nanoparticle degradation. After synthesis, QDs are solubilized in water using an amphiphilic polymer for use in biomedical applications.

Video: Synthesis of Cd-free InP/ZnS Quantum Dots Suitable for Biomedical Applications

Compact Quantum Dots for Single-molecule Imaging

Single-molecule imaging is an important tool for understanding the mechanisms of biomolecular function and for visualizing the spatial and temporal heterogeneity of molecular behaviors that underlie cellular biology 1-4. To image an individual molecule of interest, it is typically conjugated to a fluorescent tag (dye, protein, bead, or quantum dot) and observed with epifluorescence or total internal reflection fluorescence (TIRF) microscopy. While dyes and fluorescent proteins have been the mainstay of fluorescence imaging for decades, their fluorescence is unstable under high photon fluxes necessary to observe individual molecules, yielding only a few seconds of observation before complete loss of signal. Latex beads and dye-labeled beads provide improved signal stability but at the expense of drastically larger hydrodynamic size, which can deleteriously alter the diffusion and behavior of the molecule under study.
Quantum dots (QDs) offer a balance between these two problematic regimes. These nanoparticles are composed of semiconductor materials and can be engineered with a hydrodynamically compact size with exceptional resistance to photodegradation 5. Thus in recent years QDs have been instrumental in enabling long-term observation of complex macromolecular behavior on the single molecule level. However these particles have still been found to exhibit impaired diffusion in crowded molecular environments such as the cellular cytoplasm and the neuronal synaptic cleft, where their sizes are still too large 4,6,7.
Recently we have engineered the cores and surface coatings of QDs for minimized hydrodynamic size, while balancing offsets to colloidal stability, photostability, brightness, and nonspecific binding that have hindered the utility of compact QDs in the past 8,9. The goal of this article is to demonstrate the synthesis, modification, and characterization of these optimized nanocrystals, composed of an alloyed HgxCd1-xSe core coated with an insulating CdyZn1-yS shell, further coated with a multidentate polymer ligand modified with short polyethylene glycol (PEG) chains (Figure 1). Compared with conventional CdSe nanocrystals, HgxCd1-xSe alloys offer greater quantum yields of fluorescence, fluorescence at red and near-infrared wavelengths for enhanced signal-to-noise in cells, and excitation at non-cytotoxic visible wavelengths. Multidentate polymer coatings bind to the nanocrystal surface in a closed and flat conformation to minimize hydrodynamic size, and PEG neutralizes the surface charge to minimize nonspecific binding to cells and biomolecules. The end result is a brightly fluorescent nanocrystal with emission between 550-800 nm and a total hydrodynamic size near 12 nm. This is in the same size range as many soluble globular proteins in cells, and substantially smaller than conventional PEGylated QDs (25-35 nm).

We describe the preparation of colloidal quantum dots with minimized hydrodynamic size for single-molecule fluorescence imaging. Compared to conventional quantum dots, these nanoparticles are similar in size to globular proteins and are optimized for single-molecule brightness, stability against photodegradation, and resistance to nonspecific binding to proteins and cells.

Tek molekül Görüntüleme için kompakt Kuantum Noktaları

Single-molecule imaging is an important tool for  understanding the mechanisms of biomolecular function and for visualizing the  spatial and temporal ...

Mühendislik

Seeded Synthesis of CdSe/CdS Rod and Tetrapod Nanocrystals

We demonstrate a method for the synthesis of multicomponent nanostructures consisting of CdS and CdSe with rod and tetrapod morphologies. A seeded synthesis strategy is used in which spherical seeds of CdSe are prepared first using a hot-injection technique. By controlling the crystal structure of the seed to be either wurtzite or zinc-blende, the subsequent hot-injection growth of CdS off of the seed results in either a rod-shaped or tetrapod-shaped nanocrystal, respectively. The phase and morphology of the synthesized nanocrystals are confirmed using X-ray diffraction and transmission electron microscopy, demonstrating that the nanocrystals are phase-pure and have a consistent morphology. The extinction coefficient and quantum yield of the synthesized nanocrystals are calculated using UV-Vis absorption spectroscopy and photoluminescence spectroscopy. The rods and tetrapods exhibit extinction coefficients and quantum yields that are higher than that of the bare seeds. This synthesis demonstrates the precise arrangement of materials that can be achieved at the nanoscale by using a seeded synthetic approach.

A protocol for the seeded synthesis of rod-shaped and tetrapod-shaped multicomponent nanostructures consisting of CdS and CdSe is presented.

We demonstrate a method for the synthesis of multicomponent nanostructures consisting of CdS and CdSe with rod and tetrapod morphologies. A seeded ...

Kimya

Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores.

The synthesis of uniform gold nanoparticles coated with semiconductor shells of CdS or ZnS is performed. The semiconductor coating is conducted by first depositing a silver sulfide shell and exchanging the silver cations for zinc or cadmium cations.

Sentezi, Karakterizasyonu ve Hibrid Au / CdS ve Au / ZnS Çekirdek / Shell Nanopartiküller işlevselleştirilmesi

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large ...

Solubilization and Bio-conjugation of Quantum Dots and Bacterial Toxicity Assays by Growth Curve and Plate Count

Quantum dots (QDs) are fluorescent semiconductor nanoparticles with size-dependent emission spectra that can be excited by a broad choice of wavelengths. QDs have attracted a lot of interest for imaging, diagnostics, and therapy due to their bright, stable fluorescence1,2 3,4,5. QDs can be conjugated to a variety of bio-active molecules for binding to bacteria and mammalian cells6.
QDs are also being widely investigated as cytotoxic agents for targeted killing of bacteria. The emergence of multiply-resistant bacterial strains is rapidly becoming a public health crisis, particularly in the case of Gram negative pathogens 7. Because of the well-known antimicrobial effect of certain nanomaterials, especially Ag, there are hundreds of studies examining the toxicity of nanoparticles to bacteria 8. Bacterial studies have been performed with other types of semiconductor nanoparticles as well, especially TiO2 9,10-11, but also ZnO12 and others including CuO 13. Some comparisons of bacterial strains have been performed in these studies, usually comparing a Gram negative strain with a Gram positive. With all of these particles, mechanisms of toxicity are attributed to oxidation: either the photogeneration of reactive oxygen species (ROS) by the particles or the direct release of metal ions that can cause oxidative toxicity. Even with these materials, results of different studies vary greatly. In some studies the Gram positive test strain is reportedly more sensitive than the Gram negative 10; in others it is the opposite 14. These studies have been well reviewed 15.
In all nanoparticle studies, particle composition, size, surface chemistry, sample aging/breakdown, and wavelength, power, and duration of light exposure can all dramatically affect the results. In addition, synthesis byproducts and solvents must be considered16 17. High-throughput screening techniques are needed to be able to develop effective new nanomedicine agents.
CdTe QDs have anti-microbial effects alone18 or in combination with antibiotics. In a previous study, we showed that coupling of antibiotics to CdTe can increase toxicity to bacteria but decrease toxicity to mammalian cells, due to decreased production of reactive oxygen species from the conjugates19. Although it is unlikely that cadmium-containing compounds will be approved for use in humans, such preparations could be used for disinfection of surfaces or sterilization of water.
In this protocol, we give a straightforward approach to solubilizing CdTe QDs with mercaptopropionic acid (MPA). The QDs are ready to use within an hour. We then demonstrate coupling to an antimicrobial agent.
The second part of the protocol demonstrates a 96-well bacterial inhibition assay using the conjugated and unconjugated QDs. The optical density is read over many hours, permitting the effects of QD addition and light exposure to be evaluated immediately as well as after a recovery period. We also illustrate a colony count for quantifying bacterial survival.

Nanoparticles such as semiconductor quantum dots (QDs) can be used to create photoactivatable agents for anti-microbial or anti-cancer applications. This technique shows how to water-solubilize cadmium telluride (CdTe) QDs, conjugate them to an antibiotic, and perform a bacterial inhibition assay based upon growth curves and plate count.

Büyüme Eğrisi ve Plate Count tarafından Kuantum Noktaları ve Bakteriyel Toksisite Tahliller kararlı hale getirilmesi ve Bio-konjugasyon

Quantum dots (QDs) are fluorescent semiconductor nanoparticles with size-dependent emission spectra that can be excited by a broad choice of wavelengths. ...

Biyomühendislik

Synthesis of Ligand-free CdS Nanoparticles within a Sulfur Copolymer Matrix

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature solvents. These coordinating ligands help solubilize and stabilize the nanoparticles while in solution, and can influence the resulting size and reactivity of the nanoparticles during their formation. Despite the ubiquity of using ligands during synthesis, the presence of aliphatic ligands on the nanoparticle surface can result in a number of problems during the end use of the nanoparticles, necessitating further ligand stripping or ligand exchange procedures. We have developed a way to synthesize cadmium sulfide (CdS) nanoparticles using a unique sulfur copolymer. This sulfur copolymer is primarily composed of elemental sulfur, which is a cheap and abundant material. The sulfur copolymer has the advantages of operating both as a high temperature solvent and as a sulfur source, which can react with a cadmium precursor during nanoparticle synthesis, resulting in the generation of ligand free CdS. During the reaction, only some of the copolymer is consumed to produce CdS, while the rest remains in the polymeric state, thereby producing a nanocomposite material. Once the reaction is finished, the copolymer stabilizes the nanoparticles within a solid polymeric matrix. The copolymer can then be removed before the nanoparticles are used, which produces nanoparticles that do not have organic coordinating ligands. This nascent synthesis technique presents a method to produce metal-sulfide nanoparticles for a wide variety of applications where the presence of organic ligands is not desired.

Herein we present a method to synthesize ligand-free cadmium sulfide (CdS) nanoparticles based on a unique sulfur copolymer. The sulfur copolymer operates as a high temperature solvent and a sulfur source during the nanoparticle synthesis and stabilizes the nanoparticles after the reaction.

Bir Kükürt Kopolimer Matrix içinde ligand-serbest CdS Nanopartiküller Sentezi

Aliphatic ligands are typically used during the synthesis of nanoparticles to help mediate their growth in addition to operating as high-temperature ...

Enhanced Electron Injection and Exciton Confinement for Pure Blue Quantum-Dot Light-Emitting Diodes by Introducing Partially Oxidized Aluminum Cathode

Stable and efficient red (R), green (G), and blue (B) light sources based on solution-processed quantum dots (QDs) play important roles in next-generation displays and solid-state lighting technologies. The brightness and efficiency of blue QDs-based light-emitting diodes (LEDs) remain inferior to their red and green counterparts, due to the inherently unfavorable energy levels of different colors of light. To solve these problems, a device structure should be designed to balance the injection holes and electrons into the emissive QD layer. Herein, through a simple autoxidation strategy, pure blue QD-LEDs which are highly bright and efficient are demonstrated, with a structure of ITO/PEDOT:PSS/Poly-TPD/QDs/Al:Al2O3. The autoxidized Al:Al2O3 cathode can effectively balance the injected charges and enhance radiative recombination without introducing an additional electron transport layer (ETL). As a result, high color-saturated blue QD-LEDs are achieved with a maximum luminance over 13,000 cd m-2, and a maximum current efficiency of 1.15 cd A-1. The easily controlled autoxidation procedure paves the way for achieving high-performance blue QD-LEDs.

A protocol is presented for fabricating high-performance, pure blue ZnCdS/ZnS-based quantum dots light-emitting diodes by employing an autoxidized aluminum cathode.

Gelişmiş elektron enjeksiyon ve Exciton hapsi için kısmen oksitlenmiş alüminyum katot tanıtımı tarafından saf mavi kuantum nokta ışık - yayan diyotlar

Stable and efficient red (R), green (G), and blue (B) light sources based on solution-processed quantum dots (QDs) play important roles in next-generation ...

Production and Targeting of Monovalent Quantum Dots

The multivalent nature of commercial quantum dots (QDs) and the difficulties associated with producing monovalent dots have limited their applications in biology, where clustering and the spatial organization of biomolecules is often the object of study. We describe here a protocol to produce monovalent quantum dots (mQDs) that can be accomplished in most biological research laboratories via a simple mixing of CdSe/ZnS core/shell QDs with phosphorothioate DNA (ptDNA) of defined length. After a single ptDNA strand has wrapped the QD, additional strands are excluded from the surface. Production of mQDs in this manner can be accomplished at small and large scale, with commercial reagents, and in minimal steps. These mQDs can be specifically directed to biological targets by hybridization to a complementary single stranded targeting DNA. We demonstrate the use of these mQDs as imaging probes by labeling SNAP-tagged Notch receptors on live mammalian cells, targeted by mQDs bearing a benzylguanine moiety.

We provide detailed instructions for the preparation of monovalent targeted quantum dots (mQDs) from phosphorothioate DNA of defined length. DNA wrapping occurs in high yield, and therefore, products do not require purification. We demonstrate the use of the SNAP tag to target mQDs to cell-surface receptors for live-cell imaging applications.

Üretim ve Monovalent Kuantum Noktalarının Hedefleme

The multivalent nature of commercial quantum dots (QDs) and the difficulties associated with producing monovalent dots have limited their applications in ...

Inkjet Printing All Inorganic Halide Perovskite Inks for Photovoltaic Applications

A method for synthesizing photoactive inorganic&#160;perovskite quantum dot inks and an inkjet printer deposition method, using the synthesized inks, are demonstrated. The ink synthesis is based on a simple wet chemical reaction and the inkjet printing protocol is a facile step by step method. The inkjet printed thin films have been characterized by X-ray diffraction, optical absorption spectroscopy, photoluminescent spectroscopy, and electronic transport measurements. X-ray diffraction of the printed quantum dot films indicates a crystal structure consistent with an orthorhombic room temperature phase with (001) orientation. In conjunction with other characterization methods, the X-ray diffraction&#160;measurements show high quality films can be obtained through the inkjet printing method.

A protocol for synthesizing inorganic-lead-halide hybrid perovskite quantum dot inks for inkjet printing and the protocol for preparing and printing the quantum dot inks in an inkjet printer with post characterization techniques are presented.

Fotovoltaik uygulamalar için tüm inorganik Halide Perovskite mürekkepler baskı mürekkep püskürtmeli

A method for synthesizing photoactive inorganic&#160;perovskite quantum dot inks and an inkjet printer deposition method, using the synthesized inks, are ...

Synthesis of In37P20(O2CR)51 Clusters and Their Conversion to InP Quantum Dots

This text presents a method for the synthesis of In37P20(O2C14H27)51 clusters and their conversion to indium phosphide quantum dots. The In37P20(O2CR)51 clusters have been observed as intermediates in the synthesis of InP quantum dots from molecular precursors (In(O2CR)3, HO2CR, and P(SiMe3)3) and may be isolated as a pure reagent for subsequent study and use as a single-source precursor. These clusters readily convert to crystalline and relatively monodisperse samples of quasi-spherical InP quantum dots when subjected to thermolysis conditions in the absence of additional precursors above 200 &#176;C. The optical properties, morphology, and structure of both the clusters and quantum dots are confirmed using UV-Vis spectroscopy, photoluminescence spectroscopy, transmission electron microscopy, and powder X-ray diffraction. The molecular symmetry of the clusters is additionally confirmed by solution-phase 31P NMR spectroscopy. This protocol demonstrates the preparation and isolation of atomically-precise InP clusters, and their reliable and scalable conversion to InP QDs.

Synthesis of In37P20O2CR51 Clusters and Their Conversion to InP Quantum Dots

A protocol for the synthesis of In37P20(O2C14H27)51 clusters and their conversion to indium phosphide quantum dots is presented.

37P20(O2CR)51 kümeler ve inp kuantum noktalarına dönüşümlerinin sentezini

This text presents a method for the synthesis of In37P20(O2C14H27)51 clusters and their conversion to indium phosphide quantum dots. The In37P20(O2CR)51 ...

Biyobelirteç Tespitinde Gelişmiş Hassasiyet için Quantum Dot Nanobeads

Fluorescent Lateral Flow Immunoassay Based on Quantum Dots Nanobeads

Quantum dots, also known as semiconductor nanocrystals, are novel fluorescent labels for biological imaging and sensing. However, quantum dot-antibody conjugates with small dimensions (~10 nm), prepared through laborious purification procedures, exhibit limited sensitivity in detecting certain trace disease markers using lateral flow immunoassay strips. Herein, we present a method for the preparation of quantum dot nanobeads (QDNB) using a one-step emulsion evaporation method. Using the as-prepared QDNB, a fluorescent lateral flow immunoassay was fabricated to detect disease biomarkers using C-reactive protein (CRP) as an example. Unlike single quantum dot nanoparticles, quantum dot nanobead-antibody conjugates are more sensitive as immunoassay labels due to signal amplification by encapsulating hundreds of quantum dots in one polymer composite nanobead. Moreover, the larger size of QDNBs facilitates easier centrifugation separation when conjugating QDNBs with antibodies. The fluorescent lateral flow immunoassay based on QDNBs was fabricated, and the CRP concentration in the sample was measured in 15 min. The test results can be qualitatively assessed under UV light illumination and quantitatively measured using a fluorescent reader within 15 min.

Yazar Spotlight: Hassas Floresan Yanal Akış İmmünoanalizler için Yüksek Kaliteli Quantum Dot Nanoboncuklar

Here, we describe a protocol for the preparation of quantum dot nanobeads (QDNB) and the detection of disease biomarkers using QDNB-based lateral flow immunoassay strips. The test results can be qualitatively assessed under UV light illumination and quantitatively measured using a fluorescent strip reader within 15 min.

Kuantum Noktaları Nano Boncuklara Dayalı Floresan Yanal Akış İmmünoassay

Quantum dots, also known as semiconductor nanocrystals, are novel fluorescent labels for biological imaging and sensing. However, quantum dot-antibody ...