Post-grafting of silica surfaces with pre-functionalized organosilanes: New synthetic equivalents of conventional trialkoxysilanes

This article describes recent advances that have been made in the development of methods for post-grafting of silica surfaces using functionalized organosilanes. While procedures employing conventional trialkoxysilane precursors have been utilized to immobilize organic and biological molecules onto inorganic supports, such as silica and glass, they have intrinsic limitations including sensitivity to hydrolysis and slow reaction rates. In this context, new synthetic equivalents to conventional trialkoxysilanes and new grafting methods have been devised to overcome these drawbacks and improve post-grafting processes. A key feature of the new strategies is the stability of the immobilizing groups that enables the silane precursors to be functionalized and purified without decomposition before immobilization. Recent developments made in the design of immobilization methods, which employ non-catalytic and catalytic approaches, are described.