Sequential pH-dependent adsorption of ionic amphiphilic diblock copolymer micelles and choline oxidase onto conductive substrates: towards the design of biosensorsстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 26 марта 2015 г.
Аннотация:This work examines the fabrication regime and the properties of polymer-enzyme thin-films adsorbed onto conductive substrates (graphite or gold). The films were formed via two-steps, sequential adsorption of amphiphilic diblock copolymer (poly(n-butylmethacrylate)-block-poly(N,N-dimethylaminoethyl methacrylate) (PnBMA-b-PDMAEMA) micelles (1st step of adsorption), followed by the ezyme choline oxidase (ChO) (2nd step of adsorption). The solution properties of both adsorbed components were studied and the pH-dependent step-by-step fabrication of polymer-enzyme biosensor coatings revealed rather drastic differences in their enzymatic activities in dependence on the pH of both adsorption steps. The resulting hybrid thin-films represent highly active biosensors for choline with a low detection limit for choline of 30nM and a good linearity in a range between 30 nM and 100 µM. The sensitivity was found to be 175 µA×mM^(-1)×cm^(-2) and the operational stability of the polymer-enzyme thin-films could be additionally improved via enzyme-to-enzyme crosslinking with glutaraldehyde.