Citation : “ Immobilized Polydiacetylene Vesicles on Solid Substrates Use as
نویسنده
چکیده
Iodine-mediated, oxidative desulfurization promoted cyclization of N-2 pyridylmethyl thioamides serves as an efficient and versatile method for the preparation of 2-azaindolizines (imidazo[1,5-a]pyridines) and rare 2-azaindolizine sulfur-bridged dimers. The 2-azaindolizines prepared in this manner are readily converted to a variety of fluorescent compounds by using transition-metal-catalyzed cross-coupling reactions. • Citation: “Fabrication of a Superhydrophobic Surface from a Smectic Liquid-Crystal Defect Array,” Kim, Y. H.; Yoon, D. K.; Jeong, H. S.; Kim, J. H.; Yoon, E. K.; Jung , H. T. Adv. Funct. Mater., 2009, 19, 3008–3013. Abstract: A novel fabrication method is developed for the preparation of superhydrophobic surfaces. The procedure uses focal conic structures of semi-fluorinated smectic liquid crystals (LCs) whose periodic toric focal conic domains (TFCDs) are prepared on a surface modified substrate. Reactive ion etching (RIE) on the periodic TFCD surface leads to a superhydrophobic surface with a water contact angle of 1608 and a sliding angle of 28 for a 10 mL water droplet. The results show that this phenomenon is due to the development of a dual-scale surface roughness arising from the nanoscale protuberance caused by applying the RIE process to the top of the microscale TFCD arrays. The unique surface behavior is further verified by demonstrating that RIE on a flat lamellar liquid crystal film, in which the director is aligned parallel with surface, results in a relatively low hydrophobicity as compared to when periodic TFCDs are subjected to REI. The observations made in this publication suggest that a new approach exists for selecting potential candidates of superhydrophic surface formation based on spontaneous self-assembly in smectic liquid-crystalline materials.
منابع مشابه
Label-free detection with polydiacetylene vesicle immobilized on the substrate
Polyacetylene vesicle has attracted attentions due to its unique chromatic properties, such as blue-to-red transition. The liposome-like vesicle was immobilized on solid substrates to detect small quantity analytes. In this case, fluorescence was used for detection. We successfully detected protein and bacteria using antibodies or aptamers on the vesicles as probes. Recently, we developed a dif...
متن کاملA polydiacetylene-based fluorescent sensor chip.
Self-assembled diacetylene vesicles were spotted and immobilized on aldehyde-modified glass substrates using conventional microarray technology. Irradiation of the immobilized diacetylenes allowed generation of nonfluorescent "blue-phase" polydiacetylene (PDA) arrays. Specific interaction of the PDA vesicle arrays with carbohydrates or poly(acrylic acid) solutions afforded fluorescent profiles.
متن کاملResponsive Polydiacetylene Vesicles for Biosensing Microorganisms
Polydiacetylene (PDA) inserted in films or in vesicles has received increasing attention due to its property to undergo a blue-to-red colorimetric transition along with a change from non-fluorescent to fluorescent upon application of various stimuli. In this review paper, the principle for the detection of various microorganisms (bacteria, directly detected or detected through the emitted toxin...
متن کاملLabel-free detection of bacterial RNA using polydiacetylene-based biochip.
We developed a simple and effective polydiacetylene-based, label-free multiplex DNA chip for the detection of various pathogenic microorganisms. A novel immobilization method of PDA vesicles on glass slides was exploited using α-cyclodextrin (α-CD). The surface topography of the efficiently immobilized PDA vesicles was confirmed using scanning electron microscopy (SEM) and atomic force microsco...
متن کاملPolydiacetylene vesicles functionalized with N-heterocyclic ligands for metal cation binding.
Self assembled poly diacetylene (PDA) based blue vesicles LS-Terpy, LS-DPA, LS-DP and LS-DEA with metal chelating sites have been prepared and characterized. Their response to the presence of metal cations in buffered aqueous solution has been investigated by monitoring changes of colour, UV-Vis absorption and emission. The addition of zinc, manganese, cadmium, mercury or silver salts to soluti...
متن کامل