Eco-friendly Synthesis of Silver Nanoparticles Using Lantana camara Extract and Their Antimicrobial Potential Against Escherichia coli

Abstract

Background: Agar well inhibition zones combine biological response with material transport and release. Aim: We examine recorded characterization images and a four-level zone matrix for ten selected Escherichia coli isolates exposed to a Lantana camara silver preparation. Methods: The optical spectrum has a maximum near 445 nm, EDX identifies silver in the analyzed region, and five FE-SEM annotations span 55.67–91.46 nm. Results: All ten isolates show increasing visible diameters across the three higher nominal concentrations, with means of 12.79, 18.75 and 24.21 mm; five have no visible zone at the lowest concentration. Six of 45 comparable isolate pairs reverse order between the fully visible endpoints. A shared-slope log-label description has an internal omitted-dose RMSE of 1.05 mm, but does not reproduce these reversals. A finite-source mathematical model explains why endpoint zones alone cannot separately identify transport, release, growth-critical time, releasable mass and inhibitory threshold. Across 120 generated groups per mechanism, median synthetic extrapolation error increases from 0.37 to 0.76 mm under misspecified mass availability. Conclusion: An independent published matrix provides a separate example of dose-dependent isolate ordering. The case supports a descriptive concentration trend and limits on its interpretation. Regional characterization and nominal concentration labels do not establish delivered active-silver mass, nanoparticle-specific activity or clinical efficacy.