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Gonzalo García-Espejo, Marta Pérez-Morales, Michel Goldmann, María T Martín-Romero, Juan J Giner-Casares, Luis Camacho
Mixed Langmuir monolayers of 10,12-Pentacosadiynoic acid (DA) monomer and an amphiphilic Hemicyanine dye derivative have been formed at the air/water interface. Two derivatives of docosylpyridinium have been used, with either one included in the monolayer in 1:1molar ratio. The DA monomers within the mixed monolayers have been polymerized in situ at the air/water interface. The crystalline structure of the monolayer and the kinetics of polymerization have been probed by grazing incidence X-ray diffraction (GIXD)...
August 22, 2017: Journal of Colloid and Interface Science
Ying Wang, Hanwen Pei, Yan Jia, Jianhua Liu, Zelun Li, Kelong Ai, Zhongyuan Lu, Lehui Lu
Early detection of ovarian cancer, the most lethal type of gynecologic cancer, can dramatically improve the efficacy of available treatment strategies. However, few screening tools exist for rapidly and effectively diagnosing ovarian cancer in early stages. Here, we present a facile "lock-key" strategy, based on rapid, specific detection of plasma lysophosphatidic acid (LPA, an early stage biomarker) with polydiacetylenes (PDAs)-based probe, for the early diagnosis of ovarian cancer. This strategy relies on specifically inserting LPA "key" into the PDAs "lock" through the synergistic electrostatic and hydrophobic interactions between them, leading to conformation transition of the PDA backbone with a concomitant blue-to-red color change...
August 14, 2017: Journal of the American Chemical Society
Jinkyu Roh, Su Yeon Lee, Sangho Park, Dong June Ahn
The immunochromatographic assay (ICA) using a nitrocellulose (NC) membrane offers several advantages. This technique is a rapid and straightforward method in contrast to other immunoassays. Polydiacetylene (PDA) vesicles have unique optical properties, displaying red color and red fluorescence at the same time. In this system, red-phase PDA vesicles are used as a fluorescent dye as well as a surface for immobilized hepatitis B surface antibody (HBsAb). PDA has a remarkable stability compared with other fluorescent dyes...
August 17, 2017: Chemistry, An Asian Journal
P Maffert, S Reverchon, W Nasser, C Rozand, H Abaibou
Point-of-care diagnosis based on nucleic acid testing aims to incorporate all the analytical steps, from sample preparation to nucleic acid amplification and detection, in a single device. This device needs to provide a low-cost, robust, sensitive, specific, and easily readable analysis. Microfluidics has great potential for handling small volumes of fluids on a single platform. Microfluidic technology has recently been applied to paper, which is already used in low-cost lateral flow tests. Nucleic acid extraction from a biological specimen usually requires cell filtration and lysis on specific membranes, while affinity matrices, such as chitosan or polydiacetylene, are well suited to concentrating nucleic acids for subsequent amplification...
June 1, 2017: European Journal of Clinical Microbiology & Infectious Diseases
Marcos Fernandez-Castano Romera, René P M Lafleur, Clément Guibert, Ilja K Voets, Cornelis Storm, Rint P Sijbesma
Biomimetic, strain-stiffening materials are reported, made through self-assembly and covalent fixation of small building blocks to form fibrous hydrogels that are able to stiffen by an order of magnitude in response to applied stress. The gels consist of semi-flexible rodlike micelles of bisurea bolaamphiphiles with oligo(ethylene oxide) (EO) outer blocks and a polydiacetylene (PDA) backbone. The micelles are fibers, composed of 9-10 ribbons. A gelation method based on Cu-catalyzed azide-alkyne cycloaddition (CuAAC), was developed and shown to lead to strain-stiffening hydrogels with unusual, yet universal, linear and nonlinear stress-strain response...
July 17, 2017: Angewandte Chemie
Yukiko Ishijima, Mamoru Okaniwa, Yuya Oaki, Hiroaki Imai
Nanosheets have attracted much interest because of their characteristic properties originating from anisotropic and flexible structures. Inorganic nanosheets are synthesized from precursor layered compounds through exfoliation in a liquid phase. In contrast, a versatile exfoliation approach has not been fully studied for organic layered compounds. Here we report two exfoliation approaches for organic layered compounds. Hydrophilic and hydrophobic polydiacetylene (PDA) nanosheets, around 5 nm in thickness, are obtained through exfoliation of the layered precursor in aqueous and nonpolar organic media, respectively...
January 1, 2017: Chemical Science
Machi Takeuchi, Hiroaki Imai, Yuya Oaki
Organic layered materials have intercalation and dynamic properties. The dynamic properties are tuned by the intercalation of the guests. In general, however, it is not easy to achieve the homogeneous and thin coating of the layered materials on substrates with complex shapes because of the two-dimensional anisotropic structures. In the present work, the layered organic composites were homogeneously coated on a variety of substrates for application to practical devices. The metal-ion-intercalated layered polydiacetylene (PDA-M(n+)) with tunable stimuli-responsive color-change properties was coated on substrates, such as paper and cotton consisting of cellulose fibers...
May 3, 2017: ACS Applied Materials & Interfaces
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...
June 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...
August 2017: SLAS Technology
Maarten B 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 was 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(TM) 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
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