NITRILOTRIACETIC ACID-COPPER(II) MONOLAYER DEPOSITED ON A GOLD ELECTRODE FOR THE IMMOBILIZATION OF HISTIDINE TAGGED V DOMAIN OF RECEPTOR FOR ADVANCED GLYCATION END PRODUCTS-THE BASIS OF AMYLOID-BETA PEPTIDE SENSING

摘要

The preparation and application of biosensors for the determination of amyloid-beta16-230 peptide are described. The redox active nitrilotriacetic acid_(single)-copper(II)-histidine6-receptor for advanced glycation end products V domain and redox active nitrilotriacetic aciddouble-Cu(II)-histidine6-receptor for advanced glycation end products V domain complexes were employed as an analytically active layer of biosensors. The preparation procedure consists of three steps: creation of a mixed layer composed of N-acetylocysteamine and thiol derivatives of nitrilotriacetic acid, complexation of Cu(II) on the N-acetylocysteamine-nitrilotriacetic acid layer, and immobilization of histidine-tagged V domains, natural or mutant on the surface of a gold electrode modified with a N-acetylocysteamine-nitrilotriacetic acid layer. The biosensors were used for the study of the interactions between the histidine-tagged V domains of receptor for advanced glycation end products and amyloid-beta16-23' peptide. Each step was controlled by cyclic voltammetry, Osteryoung square-wave voltammetry, and atomic force microscopy. Comparisons of the electrochemical parameters of biosensors, incorporating single as well as double nitrilotriacetic acid molecules, were investigated. Both types of biosensors were used for determination of amyloid-beta16-23' peptide, and the mechanism of electroanalytical signals generation is reported.