Figure 1

(A) Optical microscopy characterization of silver nanoclusters biosynthesized in situ by HeLa cells 24 h after their incubation with [Ag(GSH)]⁺, 160 μg/mL. Curve a: UV-Vis absorption spectrum of the relevant silver nanoclusters; curve b: excitation spectrum; curve c: fluorescence emission spectrum (Em), with excitation wavelength at 590-nm. Inset: pictures of biosynthesized Ag nanocluster solution under room light (left) and excitation source (right) irradiations. (B) Characterization of the silver nanoclusters biosynthesized in situ by HeLa cells after incubation for 24 h or 48 h with [Ag(GSH)]⁺. (a) TEM image of biosynthesized silver nanoclusters, evidencing the ~0.1 nm interplanar spacing of the silver nanoclusters (inset). (b) Hydrodynamic diameter measured using DLS (mean value ca. 1.1 nm).