One-step electrochemical deposition of Prussian Blue–multiwalled carbon nanotube nanocomposite thin-film: preparation, characterization and evaluation for H2O2 sensing

Abstract

Prussian Blue–multiwalled carbon nanotube-modified gold (PB–MWCNT/Au) electrodes were successfully fabricated using the electrochemical co-deposition method in which the MWCNTs not only act as a carrier of PB, but also as a modifier for a catalytic function. Fourier transform infrared spectra proved that PB assembled on the surface of MWCNTs through electrochemical co-deposition. Scanning electron microscopy images showed that a relatively porous PB–MWCNT film was formed. Cyclic voltammetry and electrochemical impedance spectroscopy revealed that a PB-coated MWCNTs composite film improved electron and ion transfer relative to pure PB films and also exhibited larger electrode-specific capacitance than PB alone. Compared with a PB film, the PB–MWCNT composite film showed a larger response current to the reduction of H₂O₂ because of the synergistic effects between the MWCNTs and PB particles. This fast, sensitive, and efficient sensor for H₂O₂ was observed with a detection sensitivity of 856 μA mM⁻¹ cm⁻², and the linear range spanned the concentration of H₂O₂ from 1 μM to 5 mM. The detection limit was 23 nM at a signal-to-noise ratio of 3. The method presented here demonstrates the great potential for CNTs and other inorganic or metal nanoparticles for constructing bioelectronic devices and biosensors.