Aminomethyl Phosphonic Acid-Functionalized Gold Nanorods for Integrated Visual Detection, Monitoring, and Removal of Uranium from Groundwater and Industrial Effluent Simulants

Gold nanorods (GNRs) have become a key component in surface plasmon resonance (SPR)-based colorimetric methods for the detection of heavy metals in groundwater. However, sensitivity, selectivity, and performance in complex matrices limit the method’s efficacy. Here, we report a detection-monitoring-removal (DMR) strategy for selective 50 μg/L uranyl detection with a resolution of 7.5 ng/L using aminomethyl phosphonic acid (AMPA)-functionalized GNRs (f-GNRs). Density Functional Theory (DFT) elucidated the interaction between AMPA and GNRs, emphasizing the charge distribution characteristics. Experimental investigation using transmission electron microscopy (TEM), Raman spectroscopy, FTIR spectroscopy, and UV–vis spectroscopy unfurled the structure–property correlations of f-GNRs, and it offers substantial experimental support to theoretical findings. A mathematical modeling of an asymmetric plasmonic band using a skewed Lorentzian function reveals a linear relationship between the plasmonic band and uranium concentration, with an exceptional selectivity against metal ions such as Na, Mg, K, Ca, Cd, and Hg. Additionally, f-GNRs allowed U recovery with a loading capacity of 20 μg/mL and validated detection against nuclear plant complaint simulated High-Level Waste (HLW). So, our approach employing f-GNRs provides an efficient strategy for the detection, separation, and extraction of uranyl ions from both groundwater and industrial effluents, offering a promising solution for environmental remediation.