Date of Graduation
Fall 2025
Degree
Master of Science in Chemistry
Department
Chemistry & Biochemistry
Committee Chair
Cyren Rico
Abstract
Nanotechnology is gaining attention in agriculture, majorly due to their potential benefits in farming practices. Sulfur and molybdenum disulfide nanoparticles are reported to enhance plant growth, protection, and nutrient delivery. However, there is a need to understand how nano-fertilizers affect the metabolites and nutritional benefits of plants. Here, lettuce was cultivated under greenhouse in one of three treatments: control, 50 ppm S NPs, and 20 ppm MoS2 NPs. A method was developed on Liquid Chromatography – Mass Spectrometry (LC-MS) instrument to quantify the concentration of amino acids and antioxidants in the harvested lettuce plants. Inductively Coupled Plasma – Mass Spectrometry (ICP-MS) was used to analyze elemental compositions of macro and micronutrients of the plants. Other phenotypic parameters such as biomass, chlorophyll content, and oxidative stress were also measured to determine the overall effect of the nanoparticles on plant health. Interestingly, no significant difference was seen in the biomass, chlorophyll content, and lipid peroxidation between treatments. The elemental concentrations were mostly not affected except for a decrease in S content and an increase in Mo content of plants treated with MoS2 NPs. Significant changes of up to 164% were detected in the levels of six antioxidants in the nanoparticle-treated plants including glutathione, tocopherol, ferulic acid, vanillic acid, p-coumaric acid, and trifluoromethyl cinnamic acid. Although most of the detected amino acids show no significant difference across treatments, the levels of leucine, isoleucine, serine, and asparagine were up-regulated by up to 50%, and glutamine level was down-regulated by 58%, in plants exposed to MoS2 NPs compared to control and S NPs. The findings revealed that S NPs and MoS2 NPs caused dysregulation in antioxidants and amino acids but did not affect growth and oxidative stress. Furthermore, an LC-MS method was developed that effectively differentiated between metabolite dysregulation in lettuce exposed to S NPs and MoS2 NPs.
Keywords
agriculture, crops, dysregulation, metabolite, nutritional content, oxidative stress
Subject Categories
Analytical Chemistry | Environmental Chemistry
Copyright
© Mary Fakunle
Recommended Citation
Fakunle, Mary, "LC-MS Discriminates Between Effects of Sulfur Nanoparticles vs Molybdenum Disulfide Nanoparticles on Lettuce (Lactuca Sativa)" (2025). Graduate Theses/Dissertations. 4126.
https://bearworks.missouristate.edu/theses/4126
