*2.5. ROS Analyses*

Dichlorodihydrofluorescein diacetate (DCFH-DA) (Sigma-Aldrich, St. Louis, MO, USA) was used to measure reactive oxygen species (ROS) levels in the zebrafish. The zebrafish embryos were exposed to AgNPs and ZnONPs solutions beginning at 4 hpf, and the DCFH-DA assay was conducted at 96 hpf. In the experimental procedure, we initially performed three washes with deionized water to remove solutions of AgNPs and ZnONPs and impurities from the surface of the zebrafish. Then, live samples were incubated with 5 μg/mL DCFH-DA at 28 ◦C for 1 h and coated with aluminum foil to protect them from light. After the incubation, the living fish were rinsed with deionized water three times. The embryos were fixed with 3% methyl cellulose to prevent movement, and images were captured immediately.

### *2.6. LysoTracker RED DND-99 Analyses*

LysoTracker RED DND-99 (Sigma-Aldrich, St. Louis, MO, USA) reagen<sup>t</sup> was used to evaluate lysosomes and autophagy in the zebrafish. The procedure was performed according to the manufacturer's protocol. Briefly, the samples were collected at 72 hpf and rinsed with deionized water three times. Then, the embryos were incubated with 10 μM lysosomal probe for 1 h at 28 ◦C. After the incubation, we used deionized water to wash the embryos three times and then fixed the embryos with 3% methyl cellulose. Embryos were observed and imaged using a fluorescence microscope (BX51, Olympus Co., Tokyo, Japan).
