Fig. 1

Normalized luminescence spectra of (CdSe/ZnS)-Cys 558 quantum dots in phosphate buffer (7.5 mM) at pH 7.3: fresh prepared (black line, λ_max = 558 nm), after 3 months in the refrigerator at 276 K (aged QD) without TPPS₄ (red line, λ_max = 556 nm), and at addition of [TPPS₄] = 5.0 μM to aged QD (blue line, λ_max = 559 nm), λ_ex = 480 nm