Table 1: Properties of quantum dots after their solubilization with DL-Cys.

Sample* PL emission peak (nm) Quantum yield (%) Diameter(nm)** Hydrodynamic diameter (nm)*** ζ-potential (mV)
QD570 570 48 3.1 6 ± 2 -33.4
QD600 599 42 4.6 7 ± 2 -37.5

*For all measurements, QD concentrations of about 0.5-1.5 µM were used. In all cases, the absorbance at the first excitation band was < 0.10; **Diameters of the fluorescing CdSe cores of CdSe/ZnS QDs were calculated as previously described [38], then corrected, where necessary, according to Jasieniak, et al. [40]; ***The hydrodynamic diameters were measured using the Dynamic Light Scattering (DLS) technique as previously described [44]. The mean values and standard deviations for three independent experiments are shown.