Synthesis and Characterization of Indole-3-Butyric Acid-Loaded Hollow Mesoporous Silica Nanoparticles: Effects on Plant Rooting Induction

In recent years, nanocarriers have been employed for the encapsulation and sustained release of agrochemicals with a particular focus on auxins. Given their potential applications, they have attracted significant interest in order to enhance bioavailability and improve crop yields and nutrient quality. The synthesis and efficacy of hollow mesoporous silica nanoparticles (HMSNP_S) as a nanocarrier for the loading of the hormone indole-3-butyric acid (IBA) and its effect on rooting tobacco plants have been investigated in this study. The physicochemical properties of the nanoparticles were confirmed through a comprehensive range of analyses. The average particle size of the IBA-HMSNP_S was measured by Dynamic light scattering analysis of 452 nm (nm). Scanning electron microscope studies revealed that the nanoparticles were spherical in shape with an average size of approximately 85 nm. The characteristic peaks of IBA on HMSNP_S were identified by Fourier transform infrared spectroscopic analysis. Furthermore, a hormone loading efficiency (HLE) of 45% was observed, and an encapsulation efficiency (EE) of up to 90% was observed for IBA hormone loading. The results revealed that for the traits assessed, the average root length and the longest root length were 9.43 and 10.30 cm, respectively, observed in the IBA-HMSNPS treatment with a concentration of 1 mg L⁻¹. The treatment of IBA-HMSNPS at a concentration of 3 mg L⁻¹ demonstrated the highest values for root fresh weight (1.03 g), dry weight (0.07 g), and days to rooting (2.66 days), respectively. The study’s findings suggest that hollow mesoporous silica nanoparticles (HMSNP_S) serve as a promising nanocarrier for delivering indole-3-butyric acid (IBA) hormones in agricultural contexts.