Figure 3

Absorption spectra (a), photoluminescence spectra (b) and photoluminescence decays (c) of the Au NCs and Au NCs@Chi in water. (d) Relative luminescence (I/I₀) at λ_ex=405 nm of the Au NCs and Au NCs@Chi (25 μg ml⁻¹) with 1 mM of various metal ions being added.