Silver Nanoparticle Detection in Real-World Environments via Particle Impact Electrochemistry.

Silver nanoparticles (AgNPs) suspended in bottled mineral water and in tap water were successfully detected via the nanoimpact method without the deliberate addition of electrolyte. The recorded spike charge was used to indicate the stability of the AgNPs in their suspensions. It is found that the AgNPs largely agglomerated in potable water within the first 20 min. Addition of high concentrations of citrate (>2 mM) improved the stability of the AgNPs and enabled the detection and sizing of the AgNPs monomers in these media. Aging of the potable water suspensions was independently confirmed via UV-vis spectroscopy, validating the electrochemical method for detecting nanoparticles in real-world media.