Exposure to nanoplastics induces the elevation of Zn2+ levels in cells as visualized by a Golgi apparatus-targetable ratiometric fluorescent nanosensor

Nanoplastics are prevalent in the environment and emerging evidence suggests they can induce organ injury by activating oxidative stress. Given that both nanoplastics and Zn levels are intertwined with oxidative stress, it is crucial to investigate the influence of nanoplastics on the level of labile Zn and get a better understanding of their cytotoxicity mechanisms. At the organelle level, the Golgi apparatus plays an active role in stress responses. In this study, we synthesized Golgi-Zn, the first ratiometric fluorescence nanosensor with Golgi apparatus targeting ability for monitoring of Zn. This nanosensor demonstrated high sensitivity and selectivity as well as robust pH stability for Zn sensing. The ratio of the two fluorescence signals of Golgi-Zn showed a good linearity with Zn concentration in the range of 0.5-10 μM, achieving a limit of detection of ∼72.4 nM. Furthermore, the nanosensor exhibited low cytotoxicity and effectively targeted the Golgi apparatus. Leveraging these fascinating features, we successfully applied Golgi-Zn for visualizing exogenous and endogenous Zn levels in the Golgi apparatus. Moreover, with the help of Golgi-Zn, we found that nanoplastics stimulation could increase the level of Zn in the Golgi apparatus.