Application of internal persistent fluorescent fibers in tracking microplastics in vivo processes in aquatic organisms

Tracking the in vivo transportation and localization of microplastics is the prerequisite for a better understanding of the toxicity but has not been reported yet. Fluorescent microbeads are widely used for tracking in the laboratory, whereas the most abundant microplastic (e.g., fiber) found in the field is rarely adapted. In this study, we used fiber slicer and blades to cut spinning materials into fluorescent micro-sized fibers with various lengths. Fiber slicer and blades are efficient tools to produce specific lengths of fibers. The microfibers showed a specific color under the ultraviolet irradiation; therefore, these microfibers can be clearly visualized when they are within aquatic organisms, such as water flea, shrimp, medaka, and zebrafish, which enables us to observe the whole biological processes of microfibers directly. Thus, the present study provides a novel method of microfibers preparation, and this kind of fluorescent fiber is applicable to be an efficient and convenient tracer for in vivo process observation and potential toxicological analysis in the future.