Synthesis and Functionalization of Nitrogen-doped Carbon Nanotube Cups with Gold Nanoparticles as Cork Stoppers

Nitrogen-doped carbon  nanotubes consist of many cup-shaped graphitic compartments termed as  nitrogen-doped carbon nanotube cups (NCNCs).  These ...

University of Pittsburgh

The electrochemical activity of stacked nitrogen-doped carbon nanotube cups (NCNCs) has been explored in comparison to commercial Pt-decorated carbon nanotubes. The nanocup catalyst has demonstrated comparable performance to that of Pt catalyst in oxygen reduction reaction. In addition to effectively catalyzing O(2) reduction, the NCNC electrodes have been used for H(2)O(2) oxidation and consequently for glucose detection when NCNCs were functionalized with glucose oxidase (GOx). Creating the catalysts entirely free of precious metals is of great importance for low-cost fuel cells and biosensors.

Electrocatalytic activity of nitrogen-doped carbon nanotube cups.

L&#39;activit&eacute; &eacute;lectrochimique de tasses de nanotube empil&eacute;es dop&eacute;e &agrave; l&#39;azote carbone (NCNCs) a &eacute;t&eacute; explor&eacute;e en comparaison avec des nanotubes de carbone commercial de Pt-d&eacute;cor&eacute;es. Le catalyseur de nanocup a d&eacute;montr&eacute; des performances comparables &agrave; celle de Pt de catalyseur dans la r&eacute;action de r&eacute;duction de l&#39;oxyg&egrave;ne. En plus effectivement catalyser la r&eacute;duction o (2), les &eacute;lectrodes NCNC ont &eacute;t&eacute; utilis&eacute;s pour l&#39;oxydation de l&#39;H(2)O(2) et par cons&eacute;quent pour la d&eacute;tection du glucose lorsque NCNCs ont &eacute;t&eacute; fonctionnalis&eacute;s avec glucose oxydase (GOx). Cr&eacute;er les catalyseurs totalement exempt de m&eacute;taux pr&eacute;cieux est d&#39;une grande importance pour les piles &agrave; combustible &agrave; faible co&ucirc;t et de biocapteurs.

Activit&eacute; &eacute;lectrocatalytique de tasses de nanotube de carbone dop&eacute; &agrave; l&#39;azote.

L&#39;attivit&agrave; elettrochimica Coppe del nanotubo impilati drogato con azoto carbonio (NCNCs) &egrave; stato esplorato rispetto ai nanotubi di carbonio commerciale Pt-decorato. Il catalizzatore di nanocup ha dimostrato prestazioni paragonabile a quella del Pt catalizzatore nella reazione di riduzione dell&#39;ossigeno. Oltre a catalizzare in modo efficace riduzione apparato, gli elettrodi NCNC sono stati usati per l&#39;ossidazione del H(2)O(2) e di conseguenza per il rilevamento di glucosio quando NCNCs sono stati funzionalizzati con glucosio ossidasi (GOx). Creare i catalizzatori interamente gratuiti di metalli preziosi &egrave; di grande importanza per il basso costo celle a combustibile e biosensori.

Electrocatalytic attivit&agrave; di tazze nanotubo di carbonio azoto-drogati.

Chemical sensing with polyaniline coated single-walled carbon nanotubes.

D&eacute;tection de produits chimiques &agrave; l&#39;aide de polyaniline enduit les nanotubes simple-mur&eacute;s de carbone.

Chemical sensing con polianilina rivestito nanotubi di carbonio a parete singola.

Nitrogen doping of carbon nanotubes during chemical vapor deposition synthesis can create unique stacked cup-shaped structures termed as nitrogen-doped carbon nanotube cups (NCNCs). These cups have semielliptical hollow cavities and elevated reactivity which could lead to various applications. In this work, by applying intense ultrasonication to the as-synthesized NCNCs, we demonstrated an effective mechanical method to isolate the individual cups with opened cavities from their stacks. The graphitic structures of the isolated cups and their inherent nitrogen functionalities were characterized by comprehensive microscopic and spectroscopic methods. In particular, we quantitatively determined the existence of amine functionalities on NCNCs and found that they were preferentially distributed at the open edges of the cups, providing localized reactive sites. Further, by thiolating the amine groups with 3-mercapto-propionic acid, we were able to effectively cork the isolated cups by gold nanoparticles with commensurate diameters. These cup-shaped carbon nanomaterials with controlled inner volumes and gold nanoparticle corks could find potential applications as nanoscale reaction containers or drug delivery vehicles.

Corking carbon nanotube cups with gold nanoparticles.

Azote dopage de carbone nanotubes pendant la synth&egrave;se de d&eacute;p&ocirc;t chimique en phase vapeur peut cr&eacute;er uniques empil&eacute;s en forme de tasse des structures qualifi&eacute;es de tasses de nanotube de carbone dop&eacute; &agrave; l&#39;azote (NCNCs). Ces tasses ont semielliptiques cavit&eacute;s creuses et r&eacute;activit&eacute; &eacute;lev&eacute;e qui pourrait conduire &agrave; diverses applications. Dans cet ouvrage, par application ultrasonication intense aux NCNCs comme-synth&eacute;tis&eacute;, nous avons d&eacute;montr&eacute; une m&eacute;thode m&eacute;canique efficace pour isoler les tasses individuelles avec les cavit&eacute;s ouvertes de leurs piles. Les structures graphitiques les tasses isol&eacute;s et leurs fonctionnalit&eacute;s inh&eacute;rentes d&#39;azote ont &eacute;t&eacute; caract&eacute;ris&eacute;s par des m&eacute;thodes microscopiques et spectroscopiques compl&egrave;tes. En particulier, nous quantitativement d&eacute;termin&eacute; l&#39;existence de fonctions amines sur NCNCs et trouv&eacute; qu&#39;elles &eacute;taient distribu&eacute;es pr&eacute;f&eacute;rentiellement sur les bords ouverts des coupes, fournissant des sites r&eacute;actifs localis&eacute;es. En outre, par thiolating les groupes amine avec 3-mercapto-propionique, nous avons pu effectivement de Li&egrave;ge les tasses isol&eacute;s par des nanoparticules d&#39;or avec des diam&egrave;tres proportionnels. Ces nanomat&eacute;riaux de carbone en forme de coupe avec contr&ocirc;le des volumes int&eacute;rieurs et bouchons de nanoparticule or pourraient trouver des applications potentielles comme &eacute;chelle nanom&eacute;trique conteneurs de r&eacute;action ou de la drogue v&eacute;hicules de livraison.

Bouchage des tasses de nanotube de carbone avec des nanoparticules d&#39;or.

Azoto doping di carbonio, nanotubi durante la sintesi di deposizione di vapore chimico possono creare unico impilati strutture a forma di Coppa, definiti come coppe nanotubo di carbonio drogato con azoto (NCNCs). Queste tazze sono cavit&agrave; vuote semielliptical ed elevata reattivit&agrave; che potrebbe portare a varie applicazioni. In questo lavoro, da applicare ultrasuoni intenso per la NCNCs come sintetizzato, abbiamo dimostrato un efficacia Metodo meccanico per isolare le coppette individuali con cavit&agrave; aperte da loro stack. Le strutture grafitiche le tazze isolate e loro funzionalit&agrave; intrinseche di azoto sono state caratterizzate da complete metodi microscopici e spettroscopiche. In particolare, abbiamo quantitativamente determinato l&#39;esistenza di funzionalit&agrave; ammina su NCNCs e trovato che preferenzialmente furono distribuiti presso i bordi aperti delle tazze, fornendo localizzati siti reattivi. Ulteriormente, thiolating i gruppi di ammina con acido 3-mercapto-propionico, siamo stati in grado di sughero efficacemente le tazze isolate da nanoparticelle d&#39;oro con diametri commisurati. Questi nanomateriali di carbonio a forma di Coppa con controllata volumi interni e tappi di sughero delle nanoparticelle d&#39;oro potrebbe trovare potenziali applicazioni come contenitori di reazione su scala nanometrica o droga veicoli di consegna.

Tappatrice tazze di nanotubi di carbonio con le nanoparticelle d&#39;oro.

PIK3CA mutation appears to predict a lack of response to anti-EGFR monoclonal antibody (mAb) treatment in patients with metastatic colorectal cancer (mCRC). However, the predictive value of PIK3CA mutations for survival remains inconclusive. Here, we pooled the data from published studies to estimate the association between PIK3CA mutation and survival outcomes in mCRC patients treated with anti-EGFR mAbs.

PIK3CA mutation is associated with poor survival among patients with metastatic colorectal cancer following anti-EGFR monoclonal antibody therapy: a meta-analysis.

PIK3CA mutation semble pr&eacute;dire l&#39;absence de r&eacute;ponse au traitement d&#39;anticorps monoclonaux (ACM) anti-EGFR chez les patients pr&eacute;sentant un cancer colorectal m&eacute;tastatique (mCRC). Toutefois, la valeur pr&eacute;dictive des mutations de PIK3CA pour la survie reste peu concluante. Ici, nous avons mis en commun les donn&eacute;es d&#39;&eacute;tudes publi&eacute;es pour &eacute;valuer l&#39;association entre les r&eacute;sultats de mutation et de survie PIK3CA mCRC patients trait&eacute;s par anti-EGFR mAbs.

PIK3CA mutation est associ&eacute;e &agrave; faible taux de survie chez les patients pr&eacute;sentant un cancer colorectal m&eacute;tastatique apr&egrave;s traitement d&#39;anticorps monoclonaux anti-EGFR: a meta-analysis.

PIK3CA mutazione sembra prevedere una mancanza di risposta al trattamento con anticorpo monoclonale (mAb) anti-EGFR nei pazienti con cancro del colon-retto metastatico (mCRC). Tuttavia, il valore predittivo di mutazioni PIK3CA per sopravvivenza rimane inconcludente. Qui, abbiamo riunito i dati di studi pubblicati per valutare l&#39;associazione tra risultati mutazione e sopravvivenza PIK3CA in mCRC pazienti trattati con anti-EGFR mAbs.

PIK3CA mutazione &egrave; associata a scarsa sopravvivenza tra i pazienti con cancro colorettale metastatico dopo terapia con anticorpi monoclonali anti-EGFR: una meta-analisi.

Yifan Tang

Department of Chemistry

University of Pittsburgh

Synthesis and Functionalization of Nitrogen-doped Carbon Nanotube Cups with Gold Nanoparticles as Cork Stoppers

Yifan Tang

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Chemistry

University of Pittsburgh

Synthesis and Functionalization of Nitrogen-doped Carbon Nanotube Cups with Gold Nanoparticles as Cork Stoppers

Department of Chemistry