Microplastics, nanoplastics and related products have been recently found in marine ecosystems worldwide, calling for new analytical methods for rapid detection and risk assessment. Fluorescence is a sensitive technique that when used with polarity probes can potentially detect low-polarity plastic particles in environments. Here, we evaluated the fluorescence technique to sense polystyrene microparticles directly on salt, silica and sand surfaces, using Nile Red and pyrene as polarity probes. Results show that all probes displayed fluorescence on silica and sand, whereas strong fluorescence quenching was observed on NaCl. Polystyrene particles increase the fluorescence intensity due to probe migration into their nonpolar microenvironment. In the presence of polystyrene, the spectra of Nile Red are shifted to shorter wavelengths, while the ratio of vibronic bands I₁/I₃ of fluorescence of pyrene decreases to about 1. Pyrene showed similar sensitivity toward surface-modified carboxyl polystyrene particles. On NaCl, the emission of pyrene increases linearly with polystyrene content for concentrations from 0.5 to 20 µg/g. The detection limit of polystyrene microparticles on natural sea salt using pyrene as probe is about 0.2 µg/g, while on sand, the sensitivity is about one order of magnitude lower. Overall, although being of relatively low selectivity, the fluorescence technique can be used to determine a maximum content of plastic particles of few micrometers size with little sample preparation. Fluorescence, when used in conjunction with pyrene probe, allows for detection and quantification of microplastic particles in the sub-ppm range.

最近在全球海洋生态系统中发现了微塑料，纳米塑料和相关产品，要求使用新的分析方法进行快速检测和风险评估。荧光是一种灵敏的技术，当与极性探针一起使用时，可以潜在地检测环境中的低极性塑料颗粒。在这里，我们评估了使用尼罗红和pyr作为极性探针直接在盐，二氧化硅和沙子表面上感测聚苯乙烯微粒的荧光技术。结果表明，所有探针在二氧化硅和沙子上均显示荧光，而在NaCl上观察到强烈的荧光猝灭。聚苯乙烯颗粒由于探针迁移到非极性微环境中而增加了荧光强度。在聚苯乙烯存在的情况下，尼罗红的光谱转移到较短的波长，我₁ /我₃fluorescence的荧光强度降低到约1。showed对表面改性的羧基聚苯乙烯颗粒表现出相似的敏感性。在NaCl上，浓度从0.5到20 µg / g，of的排放随聚苯乙烯含量线性增加。使用pyr作探针的天然海盐中聚苯乙烯微粒的检出限约为0.2 µg / g，而在沙子上，灵敏度低约一个数量级。总体而言，尽管选择性较低，但荧光技术可用于在样品制备很少的情况下确定几微米大小的塑料颗粒的最大含量。当与pyr探针结合使用时，荧光可以检测和定量亚ppm级范围内的微塑料颗粒。