Enzymatic recognition of hydrogen peroxide (H2O2) in human plasma samples using HRP immobilized on the surface of poly(arginine-toluidine blue)-modified Fe3O4 nanoparticles modified polydopamine; A novel biosensor

In this study, an innovative strategy was proposed for the electrocatalytical reduction and enzymatic biosensing of hydrogen peroxide (H2O2) using chronoamperometry technique. For the first time, immobilization of horseradish peroxidase (HRP) in polydopamine-modified magnetic nanoparticles (PDA-MNPs) was successfully performed. Also, poly(L-arginine/toluidine blue) film-modified glassy carbon electrode was constructed through co-electropolymerization of L-arginine and toluidine blue on the surface of GCE using cyclic voltammetry technique. The engineered hybrid thin film provides strong functionalities for efficient grafting of PDA-MNPs which, in turn, enable the covalent immobilization of HRP. The proposed biosensor was used for the detection of H2O2 in the range of 0.5-30 mu M with a low limit of quantification 0.23 mu M. It also was successfully applied for the investigation of hydrogen peroxide in human plasma samples.

Automated summary

An innovative strategy for electrocatalytical reduction and enzymatic biosensing of hydrogen peroxide was proposed in this study. The biosensor with immobilized HRP in PDA-MNPs showed efficient detection of H2O2 with low limit of quantification, and was successfully applied to human plasma samples.