Abstract: It is an object of the present invention to provide a technique of conserving a functional group used for binding a physiologically active substance in the form of an inactive ester, and converting it to an activated ester by simple operations immediately before formation of an amide bond. The present invention provides a biosensor which comprises a substrate that has been modified with a phenyl ester group having a substituent whose electron-withdrawing ability is increased as a result of a chemical reaction.

Abstract: It is an object of the present invention to provide a biosensor used to easily produce a hydrogel capable of immobilizing a physically active substance, using safe materials; and a method for producing the same. The present invention provides a biosensor which comprises a substrate having a metal layer on the surface thereof, wherein an acetoacetyl group-containing hydrophilic polymer is bound to said metal layer directly or via an intermediate layer.

Abstract: It is an object of the present invention to provide a biosensor, wherein non-specific adsorption on a surface that does not retain a physiologically active substance (reference unit) is suppressed. The present invention provides a biosensor which comprises a substrate having at least two types of surfaces on a single plane, wherein at least one of said surfaces does not retain a physiologically active substance, and wherein at least two types of hydrophilic compounds with different molecular weights are bound to said surface that does not retain a physiologically active substance.

Abstract: One object of the present invention is to provide a biosensor and a production method therefor, by which hydrogel that enables immobilization of a physiologically active substance can be conveniently produced using safe raw materials. The present invention provides a biosensor which comprises a substrate having a metal layer on its surface, wherein a hydrophilic polymer having a reactive functional group capable of reacting with a hydroxyl group or an amino group of a physiologically active substance is bound to the metal layer directly or indirectly via an intermediate layer.

Abstract: It is an object of the present invention to provide a technique of converting carboxylic acid into an active ester with no generation of air bubbles and a technique of stabilizing the obtained active ester. The present invention provides a biosensor wherein a carboxyl group existing on the surface of a substrate thereof is activated with any one compound selected from an uronium salt, a phosphonium salt or a triazine derivative which are defined in the present application, so as to form a carboxylic acid amide group.

Abstract: In a gas barrier laminate film comprising a base material film containing an inorganic compound and at least one set of inorganic layer and organic layer formed on the base material film, the base material film is formed with a resin having a glass transition temperature of 250° C. or higher. A gas barrier laminate film that has superior durability, heat resistance and gas barrier performance, shows a small difference in coefficient of linear expansion relative to an contiguous layer and can maintain superior gas barrier property even if it is bent is provided.

Abstract: A tetraalkylphosphonium salt having at least one branched alkyl chain containing 9 to 100 carbon atoms in total, an organically modified layered silicate containing the tetraalkylphosphonium salt having at least one branched alkyl chain containing 9 to 100 carbon atoms in total between layers of a layered silicate and a composition comprising the organically modified layered silicate and an organic solvent or a thermoplastic resin. There are provided a tetraalkylphosphonium salt for a layered silicate having thermal stability and dispersibility superior to those of conventional organophilized layered silicates, an organically modified layered silicate containing the tetraalkylphosphonium salt and a composition thereof.

Abstract: Disclosed are a polymer composition comprising a polymer having a glass transition temperature of 120° C. to 400° C. as a simple substance of the polymer and an organic modified layered silicate having a decomposition starting temperature of 190° C. to 350° C. and contained in the polymer, a film comprising the polymer composition, a gas barrier film comprising the film and an organic/inorganic hybrid layer obtained by the sol-gel method and provided on the film, a substrate comprising the film or the gas barrier film, and an image display device comprising at least an anode, a light-emitting organic thin film layer and a cathode on the film or the gas barrier film. There are provided a polymer composition having both of superior heat resistance and superior gas barrier property, a film comprising the polymer composition, and a gas barrier film having the film, as well as a substrate and image display device exhibiting superior precision and durability.