Single-Particle Hyperspectral Imaging Reveals Kinetics of Silver Ion Leaching from Alloy Nanoparticles

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Gold–silver alloy nanoparticles are fascinating for a number of functions, together with heterogeneous catalysis, optical sensing, and antimicrobial properties. The inert ingredient gold acts as a stabilizer for silver to forestall particle corrosion, or conversely, to regulate the discharge kinetics of antimicrobial silver ions for long-term effectivity at minimal cytotoxicity. Nonetheless, little is understood in regards to the kinetics of silver ion leaching from bimetallic nanoparticles and the way it’s correlated with silver content material, particularly not on a single-particle degree. To characterize the kinetics of silver ion launch from gold–silver alloy nanoparticles, we employed a mix of electron microscopy and single-particle hyperspectral imaging with an acquisition velocity quick sufficient to seize the irreversible silver ion leaching. Single-particle leaching profiles revealed a discount in silver ion leaching price because of the alloying with gold in addition to two leaching levels, with a big heterogeneity in price constants. We modeled the preliminary leaching stage as a shrinking-particle with a price fixed that exponentially depends upon the silver content material. The second, slower leaching stage is managed by the electrochemical oxidation potential of the alloy being steadily elevated by the change in relative gold content material and diffusion of silver atoms by way of the lattice. Curiously, particular person nanoparticles with related sizes and compositions exhibited utterly totally different silver ion leaching yields. Most nanoparticles launched silver utterly, however 25% of them appeared to arrest leaching. Moreover, nanoparticles turned barely porous. Alloy nanoparticles, produced by scalable laser ablation in liquid, along with kinetic research of silver ion leaching, present an method to design the sturdiness or bioactivity of alloy nanoparticles.


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