Nanoelectroanalysis with Carbon Nanopipettes Based on Prussian Blue-NiHCF for Hydrogen Peroxide Sensing

Area of Science:

• Electrochemistry
• Nanotechnology
• Analytical Chemistry

Background:

• Carbon nanopipettes (CNPs) offer high spatial resolution for intracellular redox monitoring.
• Current H₂O₂ sensing with CNPs faces limitations in stability and mechanistic understanding due to electrode surface chemistry under nanoconfinement.

Purpose of the Study:

• To develop a robust electrochemical sensor for H₂O₂ detection within nanoconfined environments.
• To investigate the use of Prussian Blue-Nickel hexacyanoferrate (PB-NiHCF) modified CNPs for improved H₂O₂ sensing.

Main Methods:

• Fabrication of PB-NiHCF modified carbon nanopipettes using electrodeposition.
• Characterization of thin film growth and stabilization protocols.
• Electrochemical analysis using cyclic voltammetry and double-potential step chronoamperometry (DPSC) to study the thin-layer regime.

Main Results:

• Successful electrodeposition and stabilization of PB-NiHCF thin films on CNPs.
• Demonstration of a stable H₂O₂ sensing system with a linear response up to 500 μM (R² = 0.996).
• Achieved a limit of detection of 28.9 μM for H₂O₂ at physiological pH.

Conclusions:

• The PB-NiHCF modified CNPs provide a stable and effective platform for H₂O₂ detection in nanoconfined spaces.
• This approach offers a new analytical framework for nanoscale electroanalysis and coulometric sensor development.
• The findings support potential in vivo single-cell analysis of redox processes.