Tribochemical Surface Modification of Silicon

ABSTRACT Herein, we introduce a tribochemical approach for activating silicon surfaces through mechanical scratching, triggering remarkably fast spontaneous reactions with organic molecules terminated with thiol (─SH), alcohol (─OH), or alkyne. The reaction proceeds under ambient conditions in dilute solutions (10–50 mM) without the need for light, elevated temperature, or external voltages. The resulting modified surfaces were characterized using electrochemical methods and x‐ray photoelectron spectroscopy, confirming successful attachment of the molecules. Remarkably, the reaction occurs within only 10 s of exposure to dilute solutions of the molecule, yielding substantial surface coverages of silicon‐bound ferrocenemethanol, 11‐(ferrocenyl)undecanethiol, and ferrocene‐terminated alkyne species of more than 10 14 molecules cm − 2 . We attribute this reactivity to mechanically induced cleavage of Si─Si bonds, which generates highly reactive Si surface radicals that promote bond formation with the molecules. The ability to drive rapid reactions of Si with ─SH‐ and ─OH‐containing molecules is particularly significant given the prevalence of these functional groups in biomolecules, highlighting the potential of this strategy for sensing at biointerfaces and for molecular electronics.