Characterization of Mung Plants Treated with Iron Oxide Nanoparticles Using Raman and Ultraviolet-Visible Spectroscopy Coupled with Chemometrics

Abstract

In order to meet the demands of the expanding population, nanotechnology-based materials are being investigated for a potential solution to enhance crop yield. This study examines the effect of different concentrations (0.2, 0.6, 1.0, and 1.4 mM) of iron oxide nanoparticles (Fe2O3 NPs) on mung plants using confocal micro Raman and ultraviolet-visible spectroscopy. The analysis shows that the biochemical profile of the plants is altered. The increased intensity values of carotenoids, pectin, lignin, proteins, cellulose, carbohydrates, and aliphatics observed in Raman spectroscopy, along with increased concentrations of photosynthetic pigments in ultraviolet-visible spectroscopy, suggest that Fe2O3 NPs positively impact mung. In agro-related studies, Raman spectroscopy in assistance with chemometric analysis provides a reliable, noninvasive, fast, and label-free recognition and classification of plants under biotic or abiotic stress. Principal component analysis (PCA), linear discriminant analysis (LDA), and principal component analysis-linear discriminant analysis (PCA-LDA) were applied to the Raman spectra of treated and untreated mung leaves for rapid categorization and precise prediction. The results show that PCA-LDA achieved superior predicting performance and visualization, with an accuracy of 70%, along with higher recall, precision, f1 score, and area under receiver operating characteristics curves compared to LDA. The study reveals that spectroscopic techniques combined with chemometrics have great potential for confirmatory, nondestructive, and label-free assessments of biotic and abiotic stresses in plants.