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 Zn²⁺ levels are intertwined with oxidative stress, it is crucial to investigate the influence of nanoplastics on the level of labile Zn²⁺ 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 Zn²⁺. This nanosensor demonstrated high sensitivity and selectivity as well as robust pH stability for Zn²⁺ sensing. The ratio of the two fluorescence signals of Golgi-Zn showed a good linearity with Zn²⁺ 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 Zn²⁺ levels in the Golgi apparatus. Moreover, with the help of Golgi-Zn, we found that nanoplastics stimulation could increase the level of Zn²⁺ in the Golgi apparatus.