Nano-Enabled Seed Treatment Using Bisepoxide-Polyoxypropylenetriamine Polymeric Gel with Different Embedded Zinc Sources

In the 21st century, sustainable agriculture is expected to become a major contributor to food security and improved nutrition. Amine-epoxide-based materials have great potential for use in agriculture due to their tunable physicochemical features, which are dependent on the concentration and composition of the monomers. In this work, catalyst-free green synthesis, using only water as a solvent, was performed to obtain a nanocarrier (TGel) capable of transporting nutrients after seed priming. The synthesis was based on the opening of the epoxy ring by nucleophile attack, using an amine-terminated polyether. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) techniques showed the spherical morphology of the particles, which ranged in size from 80 nm (unloaded TGel) to 360 nm (zinc-loaded TGel), respectively. Theoretical bonding analysis revealed that Zn cation species from the ZnSO₄ source interact with the polymer via σ-bonds, whereas EDTA forms hydrogen bonds with the polymer, thereby enhancing noncovalent interactions. Micro X-ray fluorescence (μ-XRF) and energy-dispersive X-ray fluorescence spectroscopy (EDXRF) provided details of the distributions of Zn in the seed compartments and shoots of cucumber plants after seed priming and plant growth, respectively. The use of the Zn-loaded TGels did not affect the physiology of the cucumber plants, as indicated by the photosynthetic efficacy, chlorophyll, and anthocyanin indices.