QSH is a group of water soluble alloy CdSSe/ZnS or CdSe/ZnS core/shell quantum dots with amphiphilic polymer coating. Their reactive group is carboxylic acid. The zeta potential of QSH is from -30mV to -50mV. Their organic layers consist of a monolayer of oleic acid/octadecylamine and a monolayer of amphiphilic polymer. The thickness of the total organic layers is about 4 nm. The hydrodynamic size of the QDs is about 8-10 nm larger than their inorganic core size measured by TEM.
QSH is very stable in most buffer solutions in the pH range of 5-10 and can survive the autoclaving (121°C for 30 min) and lyophilization processes.