Engineering optimization of silver nanoparticle synthesis using Clitoria ternatea leaf extract: response surface methodology approach and biocompatibility assessment

The biological fabrication of nanoparticles utilizing botanical extracts has gained significant attention due to its environmentally friendly and sustainable approach. In this investigation, silver nanoparticles (AgNPs) were successfully produced through an eco-friendly method employing aqueous Clitoria ternatea leaf extract, which served dual functions as both reducing and capping agent. Process parameters were systematically optimized through Response Surface Methodology using Central Composite Design, yielding optimal conditions of pH 9.0, temperature 45 °C, silver nitrate concentration 100 mM, plant extract concentration 5%, and reaction duration of 24 h. Comprehensive characterization of the resulting AgNPs through multiple analytical techniques revealed spherical morphology with an average diameter of approximately 20 nm. UV–Visible spectroscopy confirmed successful nanoparticle formation through a characteristic absorption maximum at 415 nm. FTIR identified various functional groups including halogenated compounds, amines, aromatic rings, alkenes, carbonyls, alkanes, and alcohols present in the synthesized AgNPs. X-ray diffraction analysis demonstrated the crystalline structure of the nanoparticles with a calculated size of 20 nm. SEM coupled with EDAX revealed granular and aggregated spherical particles ranging from 20–200 nm with minimal contamination. Biological activity assessment demonstrated significant cytotoxic effects against MDA-MB-231 breast cancer cell lines, achieving an IC50 value of 79.49 ± 4.35 µg/mL after 24-hour exposure. The biosynthesized Ct-AgNPs exhibited pronounced antimicrobial efficacy, demonstrated by their ability to inhibit the growth of both Gram-positive and Gram-negative bacterial strains in vitro. These findings highlight the therapeutic potential of Clitoria ternatea-mediated silver nanoparticles for anticancer applications and broader pharmaceutical uses.