Current Lifetime of Single-Nanoparticle Collision for Sizing Nanoparticles

Area of Science:

• Electrochemistry
• Nanotechnology
• Materials Science

Background:

• Accurate nanoparticle (NP) size analysis is crucial for nanotechnology applications.
• Conventional single-nanoparticle collision (SNC) methods struggle with accurate NP sizing due to NP movement artifacts affecting current intensity.
• Existing methods show significant overlap rates for differently sized NPs, limiting precise size determination.

Purpose of the Study:

• To introduce a novel, size-dependent dynamic parameter, current lifetime, for enhanced NP size analysis using SNC.
• To demonstrate the superiority of current lifetime over current intensity for distinguishing between differently sized NPs.
• To develop a more reliable electrochemical approach for accurate NP size evaluation.

Main Methods:

• Utilized single-nanoparticle collision (SNC) electrochemistry.
• Introduced and measured 'current lifetime' as a size-dependent dynamic parameter, defined as the time for current intensity to decay to 1/e.
• Analyzed current transients of platinum (Pt) and gold (Au) nanoparticles of varying sizes (10-35 nm).

Main Results:

• Current lifetime demonstrated a positive correlation with nanoparticle size.
• The overlap rates for differently sized Pt NPs (10 and 15 nm) decreased from 73% to 45% when using current lifetime.
• For Au NPs (18 and 35 nm), overlap rates reduced from 7% to 0% with the current lifetime method, achieving theoretical values.

Conclusions:

• The proposed SNC dynamics-based method, utilizing current lifetime, significantly improves the accuracy of nanoparticle size analysis.
• This approach offers a more reliable electrochemical technique for distinguishing and evaluating nanoparticle sizes compared to conventional intensity-based methods.
• The enhanced accuracy holds great potential for advancing nanotechnology and materials science applications requiring precise NP characterization.