Figure 4.

(A): absorption spectra of liquid ink containing AuNP@HS-PEG₅₀₀₀ (black) and printed on glass (dropcasted ink dried for 14 h, blue). (B): a drop of liquid ink just casted on glass. (C): same, after 14 h drying (corresponds to the blue spectrum in panel A). (D): same, after 7 days ageing (corresponds to the violet spectrum in panel E) (E): absorption spectra of the same ink (black) and evolution of the printed pattern after 1–7 days. (F): comparison of the absorption spectrum of the AuNP@HS-PEG₅₀₀₀ in water (black), of a 7 days aged print (violet), and after redissolution in water of the aged print (red). (G): TEM image of the AuNP redissolved from a 7 days aged print.