ИСТИНА

Carbon nanomaterials (carbon nanotubes, graphene oxide, etc.) have been widely exploited for engineering of electrochemical (bio)analytical devices to improve their performance, remarkably increasing conductivity and efficiency of electron transfer. As such materials are typically poorly dispersible and their dispersions are not stable, it is rather challenging to apply them for an easy and reproducible modification of electrode surfaces. This work summarizes a comprehensive approach to preparation of nanocomposite biosensor coatings containing carbon nanomaterials (MWCNTs), which are uniformly distributed within a polymer matrix. For such hybrid nanomaterials, a novel polymeric component, polystyrene-block-polydehydroalanine diblock copolymer (PS-b-PDha) bearing a hydrophobic polystyrene (PS) segment, and a hydrophilic polyzwitterionic polydehydroalanine (PDha) segment was used. PDha itself as well as PDha-based copolymers represent a promising class of polymeric materials with wide range of applications, in particular, for surface modification/functionalization and biocompatible coatings. The considered nanocomposite (PS-b-PDha@MWCNTs) materials are fine aqueous dispersions (inks), which are stable over long time. Further, they can easily be drop-casted onto electrode surfaces, e.g., screen-printed electrodes. Depending on the pH, the dispersed hybrid PS-b-PDha@MWCNTs particles can exhibit positive or negative net charges and thus can provide the electrostatic binding of correspondingly charged biomolecules to the modified electrode surfaces. A rationally designed nanocomposite biosensor based on a combination of amphiphilic polyzwitterionic PS-b-PDha diblock copolymers and carbon nanomaterials allows for optimization of such materials for a specific analytical task. Beneficial surface modification of electrodes by fine aqueous PS-b-PDha@MWCNTs dispersions provides a considerable improvement of biosensor performance. Examples of advanced direct electrochemical analysis of biomolecules (e.g., hemoproteins) are reported. The strategy presented herein represents an original, profitable and promising approach towards highly specific and sensitive biosensor coatings. (PI.18, p.129)