Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants increasingly detected in freshwater systems impacted by wastewater discharge, biosolid application, and agricultural activities. Despite growing concerns regarding PFAS accumulation in aquatic ecosystems, significant knowledge gaps remain regarding their uptake, transport, bioaccumulation, and toxicity in aquatic plants. This project aims to develop a duckweed (Lemna minor)-based monitoring platform to investigate PFAS fate and biological impacts in aquatic environments. Duckweed will be exposed to environmentally relevant concentrations of representative short- and long-chain PFAS compounds, including PFOS, PFBA, and PFHxA, to quantify uptake kinetics, translocation, and accumulation using LC-MS/MS analysis. Physiological and biochemical responses, including growth, photosynthetic performance, chlorophyll content, oxidative stress, and antioxidant defense mechanisms, will be evaluated to characterize PFAS toxicity. In parallel, a real-time electrochemical reactive oxygen species (ROS) sensing system will be integrated and validated as a rapid indicator of contaminant-induced stress. Sensor outputs will be correlated with conventional toxicity biomarkers and PFAS exposure levels to establish a proof-of-concept monitoring framework. The project will provide fundamental insights into PFAS behavior in aquatic plants while advancing innovative biosensing approaches for environmental monitoring and risk assessment. Outcomes will support future federal funding opportunities and contribute to the development of sustainable strategies for PFAS management in freshwater ecosystems.