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Ming Li, Mengyao Song, Guitai Wu, Zhenyu Tang, Yunfeng Sun, Yunbin He, Jinhua Li, Lei Li, Haoshuang Gu, Xiong Liu, Chuang Ma, Zefei Peng, Zhaoquan Ai, David J Lewis
In many 2D materials reported thus far, the forces confining atoms in a 2D plane are often strong interactions, such as covalent bonding. Herein, the first demonstration that hydrogen (H)-bonding can be utilized to assemble polydiacetylene (a conductive polymer) toward a 2D material, which is stable enough to be free-standing, is shown. The 2D material is well characterized by a large number of techniques (mainly different microscopy techniques). The H-bonding allows splitting of the material into ribbons, which can reassemble, similar to a zipper, leading to the first example of a healable 2D material...
April 7, 2017: Small
Jessica T Wen, Polrit Viravathana, Brian Ingel, Caroline Roper, Hideaki Tsutsui
This study presents a sensor strip for user-friendly, naked-eye detection of Xylella fasitdiosa, the bacterial causal agent of Pierce's disease in grapevine. This sensor uses anti- X. fastidiosa antibodies conjugated to a polydiacetylene layer on a polyvinylidene fluoride strip to generate specific color transitions and discriminate levels of the pathogen. The detection limit of the sensor is 0.8 × 10(8) cells/mL, which is similar to bacterial load in grapevine 18 days following bacterial inoculation. This sensor enables equipment-free detection that is highly desirable for in-field diagnostic tools in resource-limited settings...
January 1, 2017: SLAS Technology
Maarten Bert Callens, Wouter Crijns, Tom Depuydt, Karin Haustermans, Frederik Maes, Emiliano D'Agostino, Martine Wevers, Helge Pfeiffer, Koen Van Den Abeele
PURPOSE: The aim of this work is to model the dose dependence of the darkening of GafChromic(™) EBT3 films by combining the optical properties of the polydiacetylene polymer phases, and a modified version of the single-hit model, which will take the stick-like shape of the monomer microcrystals into account. Second, a comparison is made between the quantification of the film darkening by flatbed scanning and by UV-vis absorption spectroscopy. METHOD: GafChromic(™) EBT3 films were irradiated with a 6 MV photon beam at dose levels between 0 and 50 Gy...
March 30, 2017: Medical Physics
Wenjie Dong, Guanhua Lin, Haifei Wang, Wensheng Lu
Thermal responsive polydiacetylene derived from PAMAM dendrimer (PDA-G0) was synthesized. Unlike the ethylenediamine substituted PDA (PDA-NH2) solution, the prepared PDA-G0 vesicle solution showed reversible thermochromism property when temperature varied from 20 to 90 °C, which is due to the formation of an internal hydrogen bond in amide groups. Furthermore, PDA-G0/PMMA film with excellent stability was obtained by a mixed-drying method, which could be stored for a long time without denaturation. After polymerization by UV irradiation, it displayed much better reversible thermochromic ability and the responded temperature range became wider, from 20 to 110 °C...
March 23, 2017: ACS Applied Materials & Interfaces
Lander Verstraete, Brandon E Hirsch, John Greenwood, Steven De Feyter
Polydiacetylene polymers of defined lengths are formed from self-assembled precursors inside nanocorrals created within grafted graphite substrates. A scanning tunneling microscope tip is used to nanoshave corrals at the liquid-solid interface allowing orientationally controlled supramolecular self-assembly of linear diacetylene molecules. Electrical pulses trigger topological one-dimensional polymerization reactions that are confined by the nanocorral template dimensions.
April 11, 2017: Chemical Communications: Chem Comm
Roberto Diego Ortuso, Ugo Cataldi, Kaori Sugihara
We have demonstrated colorimetric and fluorescence detection of a peptide, melittin, based on polydiacetylene (PDA) made of 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DC(8,9)PC). The PDA used in this work has a phosphocholine headgroup, which mimics peptide-cell membrane interactions better than the conventional PDAs with carboxyl headgroups. The dose curve (colorimetric response vs. melittin concentration) showed a half maximum response at the melittin concentration of 0.1 mg ml(-1), which is similar to that reported in traditional PDA assays...
February 6, 2017: Soft Matter
Sylvie Spagnoli, Emrick Briand, Ian Vickridge, Jean-Louis Fave, Michel Schott
The absorptivities of polydiacetylenes (PDAs) used in Langmuir films or vesicles for the development of PDA sensor films or other applications such as nonlinear optics and field-effect transistors are not known, so the polymer contents cannot be deduced from experimental spectra. Here we introduce a novel method, using nuclear reaction analysis (NRA), that allows a quantitative determination of the polymer content X proportion of monomers that have been incorporated into PDA chains. We apply it to pentacosadiynoic acid (PCDA) evaporated microcrystalline films...
January 31, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Mekonnen Abebayehu Desta, Chia-Wei Liao, Shih-Sheng Sun
A unique strategy to suppress charge recombination effectively and enhance light harvesting in dye-sensitized solar cells (DSSCs) is demonstrated by the design of a new dipolar organic dye functionalized with a diacetylene unit, which is capable of undergoing a photoinduced crosslinking reaction to generate a hydrophobic polydiacetylene layer. The polydiacetylene layer serves as an electrolyte-blocking layer that effectively blocks the approach of the oxidized redox mediator and suppresses the dark current, and also plays a role in light harvesting owing to efficient energy transfer to the dipolar dyes...
January 12, 2017: Chemistry, An Asian Journal
Susmita Dolai, Susanta Kumar Bhunia, Stella S Beglaryan, Sofiya Kolusheva, Leila Zeiri, Raz Jelinek
A new hybrid system comprising polydiacetylene (PDA), a chromatic conjugated polymer, embedded within aerogel pores has been constructed. The PDA-aerogel powder underwent dramatic color changes in the presence of volatile organic compounds (VOCs), facilitated through infiltration of the gas molecules into the highly porous aerogel matrix and their interactions with the aerogel-embedded PDA units. The PDA-aerogel composite exhibited rapid color/fluorescence response and enhanced signals upon exposure to low VOC concentrations...
January 25, 2017: ACS Applied Materials & Interfaces
Ting Wang, Yunlong Guo, Pengbo Wan, Xiaoming Sun, Han Zhang, Zhongzhen Yu, Xiaodong Chen
A flexible, transparent, and portable wrist strap sensor device has been well developed from a hierarchical polydiacetylene/MoS2 nanocomposite (PDA/MoS2) film. MoS2 with a nanoflake structure and chelation ability acts as a supporter for PDA films to enhance the porosity as well as the transparency of films, which increases the sensitivity, selectivity, and application potential of a PDA sensor. The PDA/MoS2 film sensor shows a linear detection range for N,N-dimethylformamide (DMF) vapor from 0.01% to 4% with a visible blue to red color change detected by the naked eye, which is more sensitive than other organic vapors...
December 20, 2016: Nanoscale
Defan Yao, Shang Li, Xiaomin Zhu, Junchen Wu, He Tian
Peptide functionalized polydiacetylene (PDA) micelles encapsulated with camptothecin (CPT) kill ovarian cancer cells by the lysosome release of anticancer drug CPT. Moreover, the sub-30 nm PDA micelles penetrate efficiently into a tumor for enhanced therapeutic efficacy.
January 19, 2017: Chemical Communications: Chem Comm
Yueyuan Zhang, Julie Northcutt, Tim Hanks, Ian Miller, Bill Pennington, Raz Jelinek, Inyee Han, Paul Dawson
Polydiacetylene (PDA) vesicles are of interest as biosensors, particularly for pathogenic bacteria. As part of a food monitoring system, interaction with food sanitizers/surfactants was investigated. PDA vesicles were prepared by inkjet-printing, photopolymerized and characterized by dynamic light scattering (DLS) and UV/Vis spectroscopy. The optical response of PDA vesicles at various concentrations verses a fixed sanitizer/surfactant concentration was determined using a two variable factorial design. Sanitizer/surfactant response at various concentrations over time was also measured...
April 15, 2017: Food Chemistry
Mani Ulaganathan, Reinack Varghese Hansen, Nateisha Drayton, Hardik Hingorani, R Govindan Kutty, Hrishikesh Joshi, Sivaramapanicker Sreejith, Zheng Liu, Jinglei Yang, Yanli Zhao
Linear two-dimensional materials have recently attracted an intense interest for supercapacitors because of their potential uses as electrodes in next-generation wearable electronics. However, enhancing the electrochemical properties of these materials without complicated structural modifications remains a challenge. Herein, we present the preparation of a hybrid electrode system via polydiacetylene (PDA) cloaking on the surface of aligned multiwall carbon nanotubes (MWCNTs) through self-assembly based in situ photopolymerization...
December 7, 2016: ACS Applied Materials & Interfaces
Daniela Mazzier, Dario Mosconi, Giulia Marafon, Aikebaier Reheman, Claudio Toniolo, Alessandro Moretto
A symmetrical dipeptide-based diacetylene system (DAs) was found to be able to self-assemble in dichloromethane and to form a compact fiber network which resulted in a stable organogel. As a consequence of the organogel formation, we explored the possibility to run a light-induced topochemical polymerization. This is a typical reaction of ordered diacetylene moieties taking advantage from their organized packing mode resulting from fiber formation. Evidence for the generation of peptide-based polydiacetylenes is provided by Raman, UV-Vis, and CD spectroscopies and a set of microscopic techniques...
February 2017: Journal of Peptide Science: An Official Publication of the European Peptide Society
Woohyun Baek, Jung-Moo Heo, Seungwhan Oh, Sang-Hwa Lee, Jaeyong Kim, Joonyoung F Joung, Sungnam Park, Hesson Chung, Jong-Man Kim
An azobenzene-containing supramolecular polydiacetylene (PDA) crystal undergoes a photoinduced reversible blue-to-red phase transition accompanied by crystal tearing.
November 18, 2016: Chemical Communications: Chem Comm
Baiju P Krishnan, Sreedevi Raghu, Somnath Mukherjee, Kana M Sureshan
An organogelator, 2,4-undeca-diynyl-4',6'-O-benzylidene-β-d-galactopyranoside, which aligns its diacetylene upon gelation, has been synthesized. UV irradiation of its gel resulted in topochemical polymerization of the gelator forming polydiacetylene (PDA). We have used this gel-state reaction for the synthesis of surface-immobilized multi-valent glycoclusters, which showed 1000-fold enhanced binding, compared to monomers, with various galactose-binding lectins.
December 1, 2016: Chemical Communications: Chem Comm
Manoj Kumar Yadav, Vijay Kumar, Bijender Singh, Santosh Kumar Tiwari
The colorimetric assay is phospholipid/polydiacetylene vesicle-based assay used for the detection of membrane-acting peptides. Bacteriocins and halocins are antimicrobial peptides known to kill target cells by membrane disruption. Therefore, the assay was applied for high-throughput (HTP) screening of bacteriocins and halocins produced by lactic acid bacteria and haloarchaea, respectively. The assay consisted of vesicles which were synthesized using four different phospholipids: dipalmitoylphosphatydilcholine (DPPC), dimyristoylphosphatidylcholine (DMPC), dimyristoylphosphoethanolamine (DMPE) and dimyristoylphosphatidylglycerol (DMPG) in combination with diacetylene monomer 10,12-tricosadiy noic acid (TRCDA)...
November 14, 2016: Applied Biochemistry and Biotechnology
Manon Ripoll, Patrick Neuberg, Antoine Kichler, Nassera Tounsi, Alain Wagner, Jean-Serge Remy
A novel generation of pH-responsive photopolymerized diacetylenic amphiphile (PDA) micelles with a diameter of 10 nm was designed and optimized for the intracellular delivery of siRNAs. Dialysis and photopolymerization of the micelles allowed a strong reduction of the cytotoxicity of the nanovector, while the hydrophilic histidine headgroup permitted enhancing the siRNA delivery potential by improving the endosomal escape via imidazole protonation. These PDA-micellar systems were fully characterized by DLS, TEM, and DOSY-NMR experiments...
November 16, 2016: ACS Applied Materials & Interfaces
Jaqueline de Paula Rezende, Guilherme Max Dias Ferreira, Gabriel Max Dias Ferreira, Luis Henrique Mendes da Silva, Maria do Carmo Hepanhol da Silva, Maximiliano Soares Pinto, Ana Clarissa Dos Santos Pires
Bovine serum albumin (BSA) has been recognized as a marker of the cow's health, milk quality, an allergenic protein and as a carrier. Its detection is important in the food, pharmaceutical and medical industries. However, traditional techniques used to detect BSA are often time-consuming, expensive, and show limited sensitivity. This paper describes properties of polydiacetylene-triblock copolymer (L64) nanosensors, synthesized to easily detect BSA. Sensor efficiency was studied as a function of nanosensor composition, polydiacetylene chemical structures, BSA conformation and hydrophobic domain availability, using spectroscopic, calorimetric, light scattering, and electrokinetic analyses...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Chunfeng Chen, Jie Chen, Tianyu Wang, Minghua Liu
Four kinds of commercially available diacetylene (DA) monomers with different chain length, diacetylene positions were fabricated into the organogels via mixing with a chaperone gelator, an amphiphilic l-histidine ester derivative LHC18 that can help the nongelator to form gels. Upon photo irradiation with a 254 nm UV light, the white gels underwent topochemical reaction and turned into red or blue gels, depending on the DA monomer structures. Through the gel formation, the molecular chirality of LHC18 can be transferred to the polydiacetylene (PDA) and helical nanoribbon structures were obtained...
November 9, 2016: ACS Applied Materials & Interfaces
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