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 sensing.
• Existing CNP-based H2O2 sensors face limitations in stability and mechanistic understanding due to surface chemistry under nanoconfinement.

Purpose of the Study:

• To develop a novel modified carbon nanopipette for robust electrochemical detection of H2O2.
• To investigate the role of Prussian Blue-Nickel hexacyanoferrate (PB-NiHCF) in enhancing H2O2 sensing within nanoconfined environments.

Main Methods:

• Electrodeposition of PB-NiHCF thin films onto carbon nanopipettes.
• Cyclic voltammetry and double-potential step chronoamperometry (DPSC) to analyze the thin-layer electrochemical regime.
• Evaluation of material properties and catalytic activity for sensing performance.

Main Results:

• Successful fabrication and stabilization of PB-NiHCF modified CNPs.
• Demonstrated stable H2O2 sensing with a linear response up to 500 μM (R2 = 0.996).
• Achieved a limit of detection of 28.9 μM at physiological pH, suitable for in vivo applications.

Conclusions:

• The PB-NiHCF modified CNP provides a stable and effective platform for H2O2 detection in nanoconfined spaces.
• This work establishes a framework for H2O2 detection in thin-layer electrochemical cells, advancing nanoscale electroanalysis.
• Opens new avenues for coulometric sensor development and in vivo single-cell analysis.