Gold nanoparticles show electroactivity: counting and sorting nanoparticles upon impact with electrodes

Area of Science:

• Electrochemistry
• Nanomaterials Science
• Analytical Chemistry

Background:

• Gold nanoparticles (AuNPs) are widely used in various applications.
• Understanding the electrochemical behavior of AuNPs is crucial for their application.
• Electrochemical methods offer sensitive detection of nanoparticles.

Purpose of the Study:

• To investigate the electrochemical activity of gold nanoparticles in acidic media.
• To demonstrate a novel method for detecting and characterizing AuNPs using electrochemistry.
• To explore the potential of anodic particle coulometry for nanoparticle analysis.

Main Methods:

• Voltammetric monitoring of individual gold nanoparticle-electrode collisions.
• Electrochemical measurements in aqueous 0.10 M HCl.
• Utilizing oxidizing potentials greater than 1.0 V (vs. Ag/AgCl).

Main Results:

• Gold nanoparticles exhibit electroactivity at oxidizing potentials above 1.0 V (vs. Ag/AgCl).
• Voltammetry successfully detected AuNP-electrode collisions.
• The findings support the feasibility of anodic particle coulometry.

Conclusions:

• Gold nanoparticles are electroactive and can be detected via their collisions with an electrode.
• Anodic particle coulometry is a promising technique for the detection and characterization of gold nanoparticles.
• This electrochemical approach provides new avenues for nanoparticle analysis.