Figure 7

Confocal laser scanning microscopy and bright and ratiometric luminescence images of zebrafish after injection of Au NCs-Cy1 (25 μg ml⁻¹) at 37 °C (a), Au NCs-Cy1 loaded zebrafish that were treated with NaHS for 1 h (b); zebrafish stimulated with l-cysteine (c) and PPG (d) and injected with Au NCs-Cy1 (25 μg ml⁻¹) at 37 °C. The green channel was acquired by collecting the luminescence at 520±20 nm (Chan. 1), while the red channel corresponded to 610±20 nm (Chan. 2). The ratiometric luminescence images were the ratio of Chan 1. to Chan. 2.