Application of horseradish peroxidase/polyaniline/bis(2-aminoethyl) polyethylene glycol-functionalized carbon nanotube composite as a platform for hydrogen peroxide detection with high sensitivity at low potential

Polyaniline/O,O′-bis (2-aminoethyl) polyethylene glycol-functionalized multiwalled carbon nanotube (PANI/PEG–MWCNT) composite-modified electrode was successfully prepared by electropolymerization. The ionic transport in PANI/PEG–MWCNT film and its effects on the composite performance are presented. Both protonic and anionic participation in the charge compensation processes were calculated and they indicated that the presence of the PEG–MWCNT in the PANI film suppress the anionic transportation and improve the composite ability in fixing horseradish peroxidase enzyme. Finally, the adsorption between the negatively charged PANI/PEG–MWCNT nanocomposite and the positively charged Horseradish peroxidase resulted in a high sensitivity (1.01 μA L cm^?2 μmol^?1) to hydrogen peroxide. This sensor exhibited a good reproducibility and stability at an applied potential of ?100 mV vs Ag/AgCl.