Facile one-step catalytic grafting of N-hydroxysuccinimidyl-ester- functionalized methallylsilane onto silica for enzyme immobilization

A one-step grafting method of NHS-ester group is described for the immobilization of enzymes onto a silica surface at room temperature. Pure NHS-ester functionalized methallylsilane was prepared as a grafting reagent and showed remarkable grafting efficiency with acid catalysts at room temperature. As a result, mesoporous silica balls bearing a covalently immobilized enzyme could be obtained with a high loading rate compared to conventional multistep grafting methods. This one-step procedure offers the advantages of precise measurement of the high loading efficiency of the NHS-ester group, and the exclusive formation of only the NHS-ester group, which reduces the presence of unreacted functionalities. A hard day's graft: NHS-ester-functionalized methallylsilanes showed remarkable grafting efficiencies with an acid catalyst. Mesoporous silica balls bearing covalently immobilized enzyme were obtained with high loading compared with conventional multistep grafting methods.