AUTHOR=Johnson Dwight , Kim Unyoung , Mobed-Miremadi Maryam 

TITLE=Nanocomposite films as electrochemical sensors for detection of catalase activity

JOURNAL=Frontiers in Molecular Biosciences

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2022.972008

DOI=10.3389/fmolb.2022.972008

ISSN=2296-889X

ABSTRACT=Transcutaneous films that are equipped with in situ sample collection and sensing offer numerous advantages for diagnosing and treating diseases namely chronic wound healing where oxidoreductase enzymes are the main contributors to regeneration. Among these developments, cross-linked substrates have garnered attention as they simultaneously enable enzymatic reaction in a control volume extended to adsorption of redox capacitors for amplification of electrochemical signals.  In this study, the effect of catalase immobilization in mold-casted alginate-based thin films (1 mm x 6 mm x 10 mm) containing multi walled nanotubes (CNT) coated with chitosan have been studied via amperometry. Results indicate that hydrogen peroxide detection is not diffusion-limited  by the 100 m  thick  chitosan layer  if the polyelectrolyte is in contact with the sensing carbon electrode, and, the linear detection of the enzyme absent in solution is enabled by immobilization (R2 =0.9615).  The amperometric-based sensitivity of 4.55 A/mM for the optimal formulation is comparable to other nanomaterial hybrid sensing solution namely amine-functionalized graphene and electrode-conjugated enzymes. The suitability of the optimized chitosan-coated alginate slabs nano-environment for co-encapsulation of catalase and CNT was confirmed by cyclic voltammetry