An anchoring strategy for photoswitchable biosensor technology: azobenzene-modified SAMs on Si(111)
|Reviews and Highlights||Quantum Science||Molecular and Soft-matter||Ultrafast Nano-optics and Nanophotonics||Mineralogy and Geochemistry|
A mild and efficient procedure has been developed to obtain covalently attached self-assembled monolayers (SAMs) on Si(111) with photochromic azobenzene head-groups. Starting from neat or diluted carboxylic acid functionalized monolayers on-chip coupling reactions were applied to attach hydroxyl-functionalized azobenzene units to the SAMs by ester bond formation. The modified surfaces were characterized by high-resolution X-ray photoelectron spectroscopy (XPS), transmission Fourier transform infrared spectroscopy (FT-IR), and contact angle measurements. Reversible cis ↔ trans isomerizations of photoswitchable SAMs were monitored by wettability measurements.