Figure 4

Absorption (a) and photoluminescence (b) spectra of Au NCs-Cy1 (25 μg ml⁻¹) in PBS (pH 7.4) with the addition of 100 μM NaHS. Changes in the time-resolved photoluminescence decay at 512 nm (c) and 604 nm (d) of Au NCs-Cy1 (25 μg ml⁻¹) upon addition of NaHS (0−100 μM) obtained with 375 nm excitation. (e) NaHS dependence of the lifetimes of the three exponentials required to fit the luminescence decay curves at 512 nm and the corresponding linear regressions. (f) NaHS dependence of the lifetimes of the three exponentials required to fit the luminescence decay curves at 604 nm and the corresponding linear regressions.