A Hybrid Redox-Active Polymer Based on Bovine Serum Albumin, Ferrocene, Carboxylated Carbon Nanotubes, and Glucose Oxidase

We used conducting redox-active polymers based on chitosan and bovine serum albumin (BSA), covalently bound to mediators ferrocene or Neutral Red, or thionine, modified by carbon nanotubes, as a base of an amperometric biosensor for determining glucose. The structure of the obtained polymers was studied by IR spectroscopy and scanning electron microscopy. Their electrochemical characteristics were studied by cyclic voltammetry. The redox-active polymer based on BSA covalently bound to ferrocene and modified by carboxylated carbon nanotubes demonstrated the most promising characteristics. The biosensor based on the selected hybrid polymer is characterized by high sensitivity, a lower limit of determined concentrations of 0.05 mM, and a high correlation coefficient (R = 0.9919) with the results of determination of glucose in human blood by an alternative method.