Sulfonic Acid-Functionalized Gold Nanoparticles: A Colloid-Bound Catalyst for Soft Lithographic Application on Self-Assembled Monolayers

In this report, we present a new lithographic approach to prepare patterned surfaces. Self-assembled monolayers (SAMs) of the acid-labile trimethylsilyl ether (TMS-OC(11)H(22)S)(2) (TMS adsorbate) was formed on gold. 5-Mercapto-2-benzimidazole sulfonic acid sodium salt (MBS-Na(+)) was used as a ligand for gold nanoparticles. These monolayer-protected gold colloids (MPCs) were transformed into the catalytically active H(+)-form by ion exchange. This colloid-bound catalyst hydrolyzed the TMS adsorbate (TMS-OC(11)H(22)S)(2) both in solution and when self-assembled on gold surfaces. Microcontact printing of the active colloid-bound catalyst on the preformed TMS SAM led to the deposition of the colloid onto the SAMs. After the catalyst nanoparticles were rinsed off, a patterned surface was created as shown by AFM.