Mercapto-propyl functionalized mesoporous silica microspheres (MSN-SH) were synthesized by one-step method. The size of the microspheres was ranged from 130 to 150 nm, and the average pore size was about 2.79 nm. After modified the outer and inner surfaces of the MSN-SH with disulfide bonds, the other end of the disulfide bond was labeled with fluorescein isothicyanate (FITC). The stability of the disulfide bond functionalized MSN was studied in glutathione solvent. The results showed that the disulfide bond would be broken in glutathione solvent, while it could keep stable in the phosphate buffer (PBS, pH＝7.4). High resolution transmission electron microscopy (HR-TEM) and N₂ adsorption-desorption isotherm were utilized to study the morphology and porous of the MSN, and elemental analysis, thermal gravimetric analysis (TGA), Zeta potential analysis methods were used to characterize the amount of the disulfide bond grafted on the MSN. The stability of the disulfide bond in glutathione solvent was also studied by fluorescence spectrometer (FLS) and UV-visible spectrophotometer (UV-Vis).

Key words: mesoporous silica microspheres, disulfide bond, fluorescein isothicyanate (FITC), glutathione