Madison Johnson | 2026 I.S. Symposium
Name: Madison Johnson
Title: Growth Effects of Fluorescent, Biopolymer-Coated Gold Nanoparticles on Hydroponically Grown Basil
Major: Chemistry
Minor: Biology
Advisor: David Kirby
Gold nanoparticles (AuNPs) are often investigated for agricultural applications due to their potential to enhance plant growth and enable targeted delivery of nutrients and agrochemicals. Fluorescent and biopolymer coatings offer a promising strategy to improve nanoparticle uptake by plants while enabling traceability within tissues. However, the behavior of engineered nanoparticles in edible plants remains insufficiently understood. In this study, AuNPs were synthesized and modified using several strategies involving chitosan, fluorescein sodium salt, fluorescein isothiocyanate (FITC), and poly(sodium 4-styrene sulfonate) (PSS). Particle growth and surface properties were characterized using dynamic light scattering (DLS), zeta potential analysis, epifluorescence microscopy, and transmission electron microscopy (TEM). Stepwise increases in effective particle diameter were observed, indicating successful material deposition for several of the methods. Among the strategies tested, the most effective at labeling and layer formation involved conjugation of FITC and chitosan prior to surface coating of NPs. Hydroponically grown basil plants were exposed to 1 mg of the fluorescent AuNPs, and confocal microscopy was used to assess nanoparticle localization in plant tissues. Statistical analysis of leaf dry mass and leaf area showed no significant differences between treated and control plants (p > 0.05), indicating that nanoparticle exposure did not measurably affect plant growth under the specific conditions tested.
Posted in Symposium 2026 on May 1, 2026.
