Luminous polystyrene upconverted nanoparticles to visualize the traces of nano-plastics in a vegetable plant

Abstract

In light of the growing use of plastics, assessing their impact on edible plants is essential for environmental preservation and food security. Researchers have employed various traditional fluorescence labeling methods to visualize nanoplastic traces in plants. However, these techniques are hindered by limitations such as shallow penetration depth, high background noise, and interference from autofluorescence, which compromise their accuracy and applicability for studying nanoplastic behavior in plant systems. This study utilized luminous upconverted labeled polystyrene nanoparticles (PS@NaYF4:Yb+3/Er+3) to visualize nanoparticles uptake and accumulation in Komatsuna (Brassica. rapa var. perviridis) under a 980 nm near-infrared laser. Results from stereomicroscopy, scanning electron microscopy, z-depth coding, and three-dimensional visualization confirm polystyrene nanoparticles (PS-NPs) accumulation in the plant, predominantly in the roots but also in edible parts. This accumulation led to a 33.18% reduction in fresh yield and a 19.05% reduction in dry yield. Our findings highlight that PS-NPs labeling with α-NaYF4:Yb+3/Er+3 offers an innovative approach to studying nano-plastic uptake and translocation behavior in plants. Its high emission efficiency under near-infrared excitation and resistance to background fluorescence make it an excellent tool for tracking nano-plastics in complex biological and environmental systems, mitigating drawbacks associated with traditional fluorescence methods.