Preparation of monodispersed mesoporous silica spheres with tunable pore size and pore-size effects on adsorption of Au nanoparticles and urease

Monodispersed mesoporous silica spheres (MMSS) with controllable porosity and pore size were successfully prepared by calcination method in the presence of complex salts. The effect of calcination temperature on the pore size of MMSS was examined. The results show that the pore size of MMSS samples can be tuned in the range from 3.20 to 46.80 nm by varying the calcination temperature. It is worth mentioning that the pore size of MMSS can be controlled on a much larger scale by this method compared to the templating approach, by which the pore size can only be expanded up to 10 nm. It is very advantageous for the application in loading enzymes. Moreover, it could be found that the method is feasible, effective and simple. In addition, the use of various MMSS samples as adsorbents for Au nanoparticles of different sizes as well as urease has also been demonstrated. It was confirmed that MMSS with adequate surface charge and optimum matching pore size showed excellent adsorption properties for Au nanoparticles and urease.