ABSTRACT The antifungal resistance and the limitations of conventional therapies have intensified interest in metallic nanoparticles (MNPs) as next‐generation antifungal agents. This review critically evaluates the application of the nanoparticle tracking analysis (NTA) as a valuable technique for characterizing MNPs, particularly in terms of nanoparticle concentration (NPs/mL), and highlights its importance in enabling cross‐study comparisons of antifungal efficacy through particle‐based dose assessments. Despite its potential, the inconsistent reporting of nanoparticle concentration and the lack of harmonized protocols hinder meaningful comparisons across studies. To address this limitation, we propose the Particle Efficiency Index (PEI), a metric that normalizes antifungal potency by relating nanoparticle concentration (NPs/mL) to fungal inoculum load (CFU/mL). By analyzing studies involving both biologically and chemically synthesized MNPs, this review demonstrates that green‐synthesized AgNPs, particularly those produced via the bacterial route, consistently exhibited the lowest PEI values, indicating superior antifungal potency. In contrast, MNPs synthesized through chemical, fungal, or plant‐mediated synthesis often required higher particle concentrations to achieve complete inhibition of fungal growth. A comparative analysis of PEI values across relevant fungi including Candida spp., Aspergillus spp., phytopathogenic species, and other fungi not classified within the aforementioned categories, is presented. Finally, methodological recommendations are provided to promote harmonization in antifungal assays, with particular emphasis on the systematic implementation of the NTA technique.
Ramos‐Hernández et al. (Sun,) studied this question.