Preparation and characterization of immobilized indole−3−butyric acid on silver−cerium oxide nanoparticles for improving its stability and utilization in the study of plant root formation indices

The mean particle size (MPS) of IBAloaded Ag@CeO₂ nanoparticles was determined to be 389 nm via dynamic light scattering (DLS) analysis. Scanning electron microscopy (SEM) further revealed that the nanoparticles possessed a predominantly spherical morphology, with a mean diameter of approximately 136 nm. The successful immobilization of IBA onto the Ag@CeO₂ nanocarriers was confirmed by Fourier-transform infrared spectroscopy (FTIR), which identified the characteristic absorption peaks of the hormone on the nanoparticle surface. Moreover, the IBA loading process achieved a hormone loading efficiency (HLE) of 45% and an encapsulation efficiency (EE) of approximately 90%. The results showed that IBA-Ag@CeO2 NPs at a concentration of 2 mgL-1 had the highest efficiency in promoting the rooting of tobacco (<i>Nicotiana tabacum</i>) plants compared with other treatments. Our results suggest that Ag@CeO2 NPs function as an effective nanocarrier for delivering the IBA hormone, highlighting their potential applications in agricultural practices.