A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Bio-Nano Material Science and Engineering

Thesis (M. Sc.) - Asian Institute of Technology, 2024

Agriculture plays a crucial role in providing sufficient food supply, but it faces enormous challenges in maximizing the supply of agrochemicals to increase crop yields while minimizing the adverse environmental impacts of these chemicals. The repeated and unchecked use of these agricultural chemicals might be dangerous to the economy, the environment, and human health. Nanotechnology offers enormous promise in agriculture by synthesizing agrochemical delivery systems with controlled release properties, improving application efficacy and environmental safety while minimizing the negative impacts on non-target species. In recent times, there has been an increase in the use of nano-porous materials in agriculture as hosts for encapsulation of species, such as agrochemicals, allowing precise and regulated release of them. Particularly, the discovery of an entirely novel group of compounds known as Metal-Organic Frameworks (MOFs) and Metal-Organic Polyhedra (MOPs) has proven to have remarkable promise for aiding targeted delivery of agrochemicals. They are particularly important as a carrier because of their extensive surface area and adaptable pores that can take in certain guest molecules. It is important to remember that MOPs are a very new and active research area. The present study explored copper-based Metal-Organic Polyhedra (Cu-MOPs) as novel carriers for encapsulation and targeted delivery of the plant osmolyte Glycine betaine (GB), therefore alleviating salt stress. The Cu-MOPs were synthesized via a one-step procedure at room temperature by utilizing Basic Copper Carbonate (BCC) as the metal source and Isophthalic acid, and 5-amino isophthalic acid as the organic ligands for Cu-MOP-1 and Cu-MOP-2, respectively. The Cu-MOPs were also synthesized in the presence of the chemical Glycine betaine (GB), which was taken as a guest. The encapsulation efficiency, loading percentage, and release kinetics of the Cu-MOPs were determined to check the better one. Characterization methods of MOPs include FTIR, UV-analysis, XRD, etc. The MOP giving the better encapsulation and release profile was selected and used for controlled delivery of GB to the salt-sensitive rice variety Pathumthani-1 (PTT1), grown under different concentration of salt solution (0 mM and 150 mM NaCl) under greenhouse condition to alleviate salt stress. The effectiveness in mitigating the salt stress was determined by comparing the performance of the GB@MOP with pure GB.