CsPbBr3 Perovskite Nanocrystals for Visual Detection of Microplastics in Sea Sand and Marine Organism Samples

Microplastics (MPs) are emerging pollutants, considered one of the most serious threats to the ecosystem and human health. Nile Red (NR) is the most widely used dye for visualizing MPs. However, NR staining is affected by natural organic materials and shows weak fluorescence for certain types of MPs, such as polyamide (PA) and polyvinyl chloride (PVC), as well as MPs with fiber morphology. Herein, a rapid, universal staining method for visualizing MPs was proposed, using CsPbBr 3 perovskite nanocrystals (NCs) as a fluorescent dye synthesized by natural deep eutectic solvents (NADESs) as solvents and surface ligands (CsPbBr 3 @NADESs NCs). The staining method proved to be highly effective for common MPs, including PA and PVC MPs. Moreover, natural organic substances, such as cellulose, lignin, mussel shell, chitin, clam shell, shrimp shell, humic acid, and sand grains, could not be stained by CsPbBr 3 @NADESs NCs, which allowed MPs to stand out for visual detection even that the environmental samples were incompletely pre-treated. This study demonstrated CsPbBr 3 @NADESs NCs as a promising fluorescent dye for visual detection of MPs in environmental samples.