Figure 3.

Fluorescent nanocluster size determinations. Correlations of mass spec abundance with each fluorescence transition intensity observed in Figure 1A over many samples yield linear correlations of only a single species with each fluorescence transition. In addition to separately identified Au₈, nanocluster sizes (emission maxima) were determined to be Au₅ (385 nm), Au₁₃ (510 nm), Au₂₃ (760 nm), and Au₃₁ (866 nm) through linear correlation of mass abundance and fluorescence intensity at each emission maximum.