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A novel concept of generating therapeutic gas, nitric oxide (NO) via catalytic phenolic-amine “gallolamine” surface chemistry is developed. The concept is realized using plant polyphenol, gallic acid, and a glutathione peroxidase-like organoselenium compound cystamine or selenocystamine through one-step phenol-amine molecular assembling process. The resulting NO-generating coating with phenolic-cystamine or -selenocystamine framework showed the ability for long-term, steady and controllable range of NO release rates being unparalleled with any existing NO-releasing or NO-generating surface engineering toolkits. Statement of Significance Developing a facile and versatile strategy for a NO-generating coating with long-term, stable and adjustable NO release is of great interest for the application of blood-contacting materials and devices. Covalent immobilization of glutathione peroxidase (GPx)-like compound to generate NO from a material surface by exposure of endogenously existed S-nitrothiol (RSNO) is a popular strategy. However, it is generally involved in multi-step and complicated processes. Moreover, the amount of immobilized GPx-like compounds is limited by the density of introduced reactive functional groups on a surface. Herein, we propose a novel concept of catalytic plant-inspired gallolamine surface chemistry for material-independent NO-generating coatings. The concept is realized using plant polyphenol, gallic acid, and a GPx-like organoselenium compound cystamine or selenocystamine through one-step phenol-amine molecular assembling process. Without tedious multi-step synthesis, complicated surface treatments, and leakage of toxic chemicals, our unprecedentedly simple, histocompatible and biocompatible phenolic-cystamine or -selenocystamine framework demonstrated long-term, on-demand and facile dose controls of NO generated from the engineering surfaces. These unique features of such a NO-generating coating imparted a material with ability to impressively improve anti-thrombogenicity in vivo . This work constitutes the first report of an interfacial catalytic coating based on material-independent surface chemistry by plant polyphenols. This concept not only expands the application of material-independent surface chemistry in an interfacial catalytic area, but also can be a new platform for antithrombotic materials. [ABSTRACT FROM AUTHOR]

In this study, we provided the detailed characterizations of our recent HRP-AuNPs/PEDOT:BSA/Pt biosensor, constructed through a simple fabrication procedure with improved stability and good sensitivity. Raman and Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy not only confirmed the synthesis of conductive PEDOT where BSA was the template for the polymerization, but also provided further insights into the stable immobilization of AuNP on the PEDOT:BSA film. Scanning electron microscopy revealed that the attachment of AuNPs were stable under a high salt environment. The current technology demonstrates a feasible procedure to form a functional AuNPs/PEDOT:BSA film that has potential applications in the fabrication of various biosensors and electric devices.

Abstract: Two isomeric building units, 4-oxo-4-(2-pyridinylamino) butanoic acid (defined as G1) and 4-oxo-4-(3-pyridinylamino) butanoic acid (defined as G2) formed fiber- and tree-like crystals in aqueous solutions, respectively. The crystal formation process of G1 was suggested based on the layered cross section of an individual crystal and the single crystal structure. Through cooling the aqueous solutions of their mixtures under G1/G2 molar ratios ranged from 7/1 to 1/3, a series of supramolecular hydrogels were formed based on hydrogen bonds as the main driving force. As decreasing G1/G2 ratios, the first observed aggregates in solution changed from fiber to particle form, while the gelating time became longer and longer. At the collapsing temperature, the gels formed at G1/G2 ratio ⩾3/1 kept the original gel shape but released water, while at G1/G2 ratio ⩽2/1 they broke into pieces without releasing water. The “dropping ball” experiment indicated that the highest gel-to-sol dissociation temperature () is obtained at G1/G2 ratio of 2/1. As measured by UV–vis spectroscopy, the two building units distributed uniformly within the gel formed at G1/G2 ratio of 1/1, indicating they assembled together in forming hydrogel. The scanning electron microscope (SEM) and infrared spectrometer (FT-IR) analysis of the dried samples indicated that the backbone shape changed from fiber to sheet and the content of free carboxyl groups increased with decreasing G1/G2 ratios, therefore resulting in hydrogels with different stability. The simple gelator structures and the possibility in controlling gel structure and stability make the hydrogels suitable for various uses. [Copyright &y& Elsevier]

Abstract: UV/vis absorption, excitation, and emission spectroscopies are utilized to explore the association behavior of conjugated polymer, poly[2-methoxy, 5-(2′-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV), in a homologous series of linear alcohols and solvent–nonsolvent systems. We demonstrate that the aggregation, agglomeration, and collapse of isolated chains, which all take place in the poor solvents, exhibit different optical signatures. The aggregate, in which chromophores interact electronically, causes a red shift of absorption and emission spectra while the weak interaction of chromophores in the agglomerates leaves electronic properties unaltered. The collapse of isolated chain is accompanied by a blue shift of the spectra. Energy transfer from excited chromophores of non-aggregated chains to the lower energy aggregates is significantly diminished in the system of alcohol solvents, allowing separate emissions from various chromophores to occur. The optical signatures and extent of energy transfer are used as tools to elucidate the association mechanism and chain organization of isolated chains into large particles upon decreasing solvent quality. The extreme collapse of isolated chains in the very poor solvents is found to inhibit the chain organization into aggregates. [Copyright &y& Elsevier]

The metal complex, [Hg2I4(PEDT)]∞ (1), PEDT=4,5-(phenyl-ethylenedithio)-1,3-dithiole-2-thione, has been synthesized and characterized by single crystal X-ray diffraction. It is found to be an unusual organic–inorganic hybrid structure. The inorganic layer is composed of chains of Hg with bridging I, in one case doubly bridged and in the other singly, interconnected by further bridging I to complete the two dimensional connectivity. The organic layers contain pairs of centrosymmetrically related, and therefore head to tail, face to face molecules. Each molecule of such a pair participates in the formation of short S⋯S contacts with a molecule of a centrosymmetrically related neighboring molecule pair thus creating chains of molecules. The connectivity within the organic layer is completed by C–H⋯π contacts between the chains. Connectivity between the organic and inorganic layers is achieved by participation of the thione S in the coordination of one type of Hg. [Copyright &y& Elsevier]

In this study, we provided the detailed characterizations of our recent HRP-AuNPs/PEDOT:BSA/Pt biosensor, constructed through a simple fabrication procedure with improved stability and good sensitivity. Raman and Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy not only confirmed the synthesis of conductive PEDOT where BSA was the template for the polymerization, but also provided further insights into the stable immobilization of AuNP on the PEDOT:BSA film. Scanning electron microscopy revealed that the attachment of AuNPs were stable under a high salt environment. The current technology demonstrates a feasible procedure to form a functional AuNPs/PEDOT:BSA film that has potential applications in the fabrication of various biosensors and electric devices. [ABSTRACT FROM AUTHOR]