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Molecular Recognition Abilities (molecular + recognition_ability)
Selected AbstractsA Substrate-Selective Nanoreactor Made of Molecularly Imprinted Polymer Containing Catalytic Silver NanoparticlesADVANCED FUNCTIONAL MATERIALS, Issue 16 2009Song jun Li Abstract An original, substrate-selective nanoreactor is designed and characterized. The nanoreactor made of a 4-nitrophonel (NP)-imprinted polymer and Ag nanoparticles, can specifically recognize NP compared with its analogues 4-nitrophenyl acetate (NPA) and 2,6-dimethyl-4-nitrophenol (DNP). Under comparable conditions, this nanoreactor significantly accelerated the reduction of NP; however, much less acceleration is shown for its analogues. Unlike traditional Ag nanoreactors, which lack molecular recognition abilities, this unique nanoreactor is composed of molecularly imprinted networks, making substrate-selective catalysis feasible. [source] Surface plasmon resonance study on binding interactions of multivalent cyclophane hosts with immobilized guestsPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 2 2010Osamu Hayashida Abstract Guest-binding affinities of water-soluble cyclophane heptadecamer (1) and pentamer (2) with immobilized guests such as 1-pyrenylmethylamine (PMA) and 2-(1- naphthyl)ethylamine (NEA) were investigated by surface plasmon resonance (SPR) measurements. As a typical example, the binding constants (K) for 1 and 2 with the immobilized PMA as a guest were evaluated to be 2.5,×,107 and 2.7,×,106,M,1, respectively, and were much larger than that of a monocyclic reference cyclophane (K, 2.5,×,104,M,1). Interestingly, in the complexation of 1 and 2 with the immobilized guests, more favorable association and dissociation rate constant values (ka and kd, respectively) were observed in comparison with those for the monocyclic cyclophane, reflecting multivalent effects in macrocycles. The multivalent effects in macrocycles as well as molecular recognition abilities of the cyclophane oligomers were confirmed even when the guest molecules were immobilized on SPR sensor chip surfaces. Copyright © 2009 John Wiley & Sons, Ltd. [source] Aqueous catalysis by novel macromolecule metal complexes with molecular recognition abilities,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 3-4 2001Edward A. Karakhanov Abstract A number of water-soluble macromolecular metal complexes on the basis of polyethers, ,-cyclodextrins, calix[4] and calix[6]arenes functionalized by oligoethylene oxide blocks, catechol, ethylendiamine, acetylacetone, 2,2,-dipiridyl, phosphines and nitrile containing groups have been developed. Complexes showed high catalytic activity in aqueous hydroformylation, biphasic Wacker-type oxidation of various higher olefines, alkane oxidation, hydroxylation of benzene and phenol. These catalysts can be multiply reused. The application of host compounds results the extremely selectivities. Copyright © 2001 John Wiley & Sons, Ltd. [source] Structured Nucleic Acid Probes for Electrochemical DevicesELECTROANALYSIS, Issue 19 2009Rebeca Miranda-Castro Abstract The use of nucleic acid with a specific sequence and a highly ordered secondary structure such as hairpins, quadruplexes and pseudoknots as biological recognition elements and switches in biosensors is rapidly increasing because of their improved features (e.g. selectivity) when compared with the traditional linear probes. Owing to the novelty, a critical outlook of their characteristics and a compilation of the latest advances are lacking. This article describes the potential of those nucleic acids probes whose molecular recognition ability relies on a conformational change (e.g. folding/unfolding mechanism) in electrochemical sensing. It provides an overview of the toolbox of assays using these probes for genosensors and aptasensors, highlighting its performance characteristics and the prospects and challenges for biosensor design. [source] Metal ion-binding ability of tetrapeptides containing ,-aminoisobutyric acidJOURNAL OF PEPTIDE SCIENCE, Issue 3 2004Masayuki Hanyu Abstract ,-Aminoisobutyric acid (Aib), one of the C,, , -disubstituted glycines, is a sterically hindered amino acid that acts as a conformational constraint in peptides. However, studies for the application of the ability of Aib to control conformation are quite few. The paper focuses on the molecular recognition ability of acyclic oligopeptides containing Aib. Liquid,liquid extraction of nine kinds of metal ions from aqueous layers to nonpolar organic layers with acyclic tetrapeptides, X-Trp-Xaa2 -Gly-Xaa4 -NH-Ar (X = H or C6H5CH2OCO (Z), Xaa2 = Aib or Gly, Xaa4 = Leu or Ala, Ar = phenyl or 3,5-dimethylphenyl) was examined using picrate as the anion of ion pairs. The extraction behaviour of the metal ions with the tetrapeptides was investigated in the pH range from 3 to 9. In the case of basic pH regions, Cu(II) and Ag(I) were effectively extracted with Trp-Aib-Gly-Leu-NH-Ar. Pd(II) was specifically extracted with Trp-Aib-Gly-Leu-NH-Ar in acidic pH regions. The extraction percent (%E) of the peptide host, which has a 3,5-dimethylphenyl group, was even larger than that of the host, which has a phenyl group. Moreover, Pd(II) was extracted with a peptide host which has Leu and a 3,5-dimethylphenyl group in the absence of picrate as the anion of ion pairs. The free ,-amino group, the turn conformation and the hydrophobicity of peptide molecules were important factors for the extraction of the metals. Copyright © 2003 European Peptide Society and John Wiley & Sons, Ltd. [source] Design and synthesis of functional polymers by in vitro selectionPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 1-2 2004Yoshihiro Ito Abstract Combinatorial chemistry, in which targeting molecules are selected from a random molecular library, has recently developed. Among the methods devised by combinatorial chemistry, the recent progress in functional polymers that have molecular recognition ability and catalysis ability, and in bio-device polymers based on these functionalities is reviewed. Copyright © 2004 John Wiley & Sons, Ltd. [source] | |||||||||||||