Design and characterization of a multifunctional Ag/Ag(I)-coated olive stone material for enhanced preservation and antibacterial protection

A novel method has been developed for the functionalization of olive stone (OS) using (3-mercaptopropyl)trimethoxysilane (MPTMS), enabling the efficient immobilization of Ag/Ag₂O nanoparticles in a 3:2 ratio. The resulting multifunctional material, OS@MPTMS@Ag, was comprehensively characterized using a wide range of techniques, including X-ray fluorescence (XRF), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), field-emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDX), thermogravimetric analysis (TGA), Karl Fischer titration, electrophoretic mobility, mercury porosimetry, nitrogen adsorption isotherms, and Brunauer–Emmett–Teller (BET) surface area analysis. This new biomaterial was evaluated in the context of postharvest preservation, where it demonstrated effective ethylene adsorption capacity. Its application to fresh produce delayed ripening by reducing weight loss, limiting color changes, and preserving firmness. In addition, OS@MPTMS@Ag exhibited notable antimicrobial activity, inhibiting the growth of both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus . • Olive stone functionalized with AgNPs forms a novel multifunctional biomaterial. • The material delays banana ripening by adsorbing ethylene gas effectively. • Displays antibacterial activity against Gram-positive and Gram-negative strains. • Utilizes agricultural waste, supporting sustainability and circular economy goals.