Fig.2.

(A) Whole-body X-ray images of mice after i.v. injection of Au_10–11, Au₁₈ and Au₂₅ at 40min post injection. The smallest Au_10–11 is retained in kidney much longer than Au₁₈, which is in turn longer than Au₂₅, although all three AuNCs are cleared through kidneys into the bladder (top). Renal clearance efficiency of glutathione protected Au10–11, Au15, Au18, Au25, 1.7nm (~Au201), 2.5nm (~Au640) and 6nm (~Au8856) AuNPs at 24h post i.v. injection, embodying the kidney glomerulus filtration as an atomically precise ‘bandpass” barrier (bottom left). Passive tumor targeting efficiency of glutathione protected Au_10–11, Au₁₅, Au₁₈, Au₂₅, Au₂₀₁ and Au₆₄₀ at 24h post i.v. injection (bottom right). (B) Structures of each molecular component used in the ligand replacement study. (C) Schematic illustration of efficient singlet oxygen generation by Au₂₅(SR)18 nanoclusters under visible/NIR (532, 650, and 808nm) light irradiation (left). In vitro experiments demonstrate Au₂₅(Capt)18 - nanoclusters can efficiently kill Hela cells photodynamically under 808nm light irradiation (right). (D) Scheme of stepwise NIR ECL generation from lipoic acid stabilized Au₂₂ nanoclusters (Au-LA) conjugated with coreactants N,N-diethylethylenediamine (DEDA). (Adapted or reprinted with permissions from Springer Nature for (A) Ref. [63], Royal Society of Chemistry for (B) Ref. [64], American Chemical Society for (C) Ref. [66] and (D) Ref. [85].)