Fig. 5

Confocal imaging of AuNP fluorescence in 4 dpf zebrafish embryo-larvae. (A) Max intensity z-stacks of a Casper embryo-larvae control using both SPIM (Ai) and confocal microscopy (Aii/Aiii) both indicating low levels of autofluorescence. The drawn white outline indicates the position of the pronephros. (B) Max intensity z-stacks of a Casper embryo-larvae exposed to 2 mg/L of 80 nm AuNPs for 72 hrs using SPIM with (Bi) and without brightfield (Bii) and confocal microscopy (Biii) indicating little difference in signal sensitivity between the two microscopic techniques. (C) AiryScan max intensity z-stacks of 4 dpf Casper embryo-larvae after exposure to 72 hr to PEG coated 80 nm AuNPs. (Ci) A stitched max intensity image of the embryo-larvae indicating fluorescence in the pronephros. (Cii) Pronephros in Casper control embryo-larvae showing background fluorescence. (Ciii) Uptake of PEG coated 80 nm AuNPs visualised in the pronephros. (D) A max intensity confocal Z stack of a Casper zebrafish embryo-larvae exposed to 2 mg/L 80 nm AuNPs for 72 h showing their presence in the pronephros (Di, 10 ×) and in the proximal straight tubule/proximal early segment of the pronephros (Dii, 20 ×).