Surface modification of SiO2 beads with multiple hydrophobic quantum dots for bioapplications

► CdSe/ZnS and CdSe/CdxZn1 − xS quantum dots (QDs) were encapsulated into SiO2 beads. ► CdSe/ZnS QDs retained their initial photoluminescence (PL) efficiency in the beads. ► The PL efficiency of CdSe/CdxZn1 − xS QDs in the SiO2 beads decreased. ► After being surface modified, the SiO2 beads conjugated with the polystyrene beads.