Synthesis of colloidal silica nanoparticles of a tunable mesopore size and their application to the adsorption of biomolecules

Abstract

A synthetic method for the fabrication of colloidal mesoporous silica nanoparticles of a tunable mesopore size is presented. These nanoparticles form stable colloidal suspensions, have narrow particle size distributions in the 50–300 nm range and exhibit a framework-confined porosity made up of large mesopores with a diameter of up to 9 nm. The size of the mesopores was enlarged by means of two different swelling agents (SA), i.e. 1,3,5-trimethylbenzene (TMB) and N, N-dimethylhexadecylamine (DMHA). Colloidal mesoporous silica nanoparticles exhibit a strong affinity for the adsorption of hemoglobin (Hb) and the immobilization of lysozyme (Lz). These nanoparticles can adsorb up to 2080 mg Hb g −1 support and 690 mg Lz g −1 support. Moreover, the adsorption of these biomolecules on silica nanoparticles occurs very quickly and most of what is adsorbed is accommodated on the external surface area of the silica nanoparticles.