Exploring the Dipteryx alata fruit endocarp as a novel source for the synthesis of silver nanoparticles: antibacterial and photocatalytic insights for water purification

Abstract

A simple, rapid, and non-toxic method was developed to synthesize silver nanoparticles (AgNPs) using an aqueous extract from the endocarp of Dipteryx alata fruit (DAE), a tree species native to the Brazilian Cerrado. The synthesis involved mixing the DAE with a solution of AgNO3 (2 mM) at room temperature. The synthesis of AgNPs was confirmed by detecting of the surface plasmon resonance band at 421 nm. Characterization revealed spherical AgNPs with an average diameter of 137.5 ± 59.3 nm. Fourier-transform infrared spectroscopy analysis confirmed phytochemical involvement in AgNP reduction and capping, while X-ray diffraction analysis indicated their crystalline nature with a face-centered cubic structure. AgNPs exhibited antibacterial activity against Escherichia coli and Enterococcus faecalis. The zones of inhibition ranged from 10 to 14 mm for E. coli and 9 to 13 mm for E. faecalis, indicating that they were sensitive to AgNPs. Photocatalytic activity against rhodamine B (RhB) resulted in 99.3% removal in 180 min, with a degradation rate constant of 0.034 L mg−1 min−1 based on pseudo-second-order kinetics. Phytotoxicity studies confirmed the non-toxic nature of degraded RhB products on Cucumis sativus. These findings highlight the potential of AgNPs from the DAE extract in antibacterial and dye remediation applications.