Nanoplastics have attracted significant attention due to their harmful effects on the environment and organisms. However, accurately detecting and quantifying nanoplastics that are ingested by organisms poses a challenge. Conventional organic fluorescent-labeled nanoplastics have reduced labeling efficiency due to aggregation-caused quenching (ACQ), leading to artifacts caused by leakage of fluorescent molecules. To address these limitations, this study utilized AIE fluorescence for internally labeling polystyrene nanoparticles. AIE-active molecules do not emit fluorescence in dilute solutions, thus preventing accuracy issues associated with fluorescence leakage. Three model plastics (TPE@PS) of varying particle sizes were synthesized via the swelling method. The preparation parameters were optimized, followed by stability tests conducted on TPE@PS. Fluorescence microscopy imaging revealed significant uptake of TPE@PS by RAW246.7 cells. A successful standard curve of fluorescence intensity-concentration was established successfully and utilized to accurately quantify the amount of TPE@PS that was ingested by RAW246.7 cells. The results indicate a consistent increase with increasing concentration in TPE@PS uptake across all particle sizes during the fixed exposure duration of 48 h. Furthermore, RAW264.7 cells exhibited a higher propensity to uptake smaller TPE@PS particles. Flow cytometry was also employed to validated the suitability of TPE@PS as a model nanoplastic for tracing purposes.

中文翻译：

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AIE 标记的荧光聚苯乙烯纳米塑料用于巨噬细胞摄取的定量分析

纳米塑料由于其对环境和生物体的有害影响而引起了人们的广泛关注。然而，准确检测和量化生物体摄入的纳米塑料提出了挑战。传统的有机荧光标记纳米塑料由于聚集引起的猝灭（ACQ）而降低了标记效率，导致荧光分子泄漏造成的伪影。为了解决这些限制，本研究利用 AIE 荧光来内部标记聚苯乙烯纳米颗粒。 AIE 活性分子在稀溶液中不会发射荧光，从而防止与荧光泄漏相关的准确性问题。通过溶胀法合成了三种不同粒径的模型塑料（TPE@PS）。优化制备参数，然后对TPE@PS进行稳定性测试。荧光显微镜成像显示 RAW246.7 细胞显着摄取 TPE@PS。成功建立了荧光强度-浓度标准曲线，并用于准确定量 RAW246.7 细胞摄取的 TPE@PS 量。结果表明，在 48 小时的固定暴露时间内，所有粒径的 TPE@PS 吸收随着浓度的增加而持续增加。此外，RAW264.7 细胞表现出更高的吸收较小 TPE@PS 颗粒的倾向。还采用流式细胞术来验证 TPE@PS 作为用于追踪目的的模型纳米塑料的适用性。