PUB - Publikationen an der Universität Bielefeld

In this work, I have studied some characteristic and application of aromatic cross-linked self-assembled monolayers (SAMs). Aromatic Hydroxybiphenyl (HBP) SAMs can be cross-linked by e-beam irradiation and have been utilized as negative resist for e-beam pattering of silicon. I studied the sensitivity of HBP to e-beam irradiation. The necessary dose for complete cross linking of HBP was to be 20mC/cm². An extremely high thermal stability of electron cross-linked aromatic biphenyl derivative self-assembled monolayers (SAMs) is reported. Desorption of pristine Biphenylthiol SAMs occurs already at temperatures above 400K via C-S bond breaking and desorption thiolate. The pristine NBPT exhibit more stabile than pristine BPT. Despite of similar bond cleavage in cross-linked SAMs, these remain on the surface up to 1000 K, which is the highest temperature reported for a SAM. Thermal processing of e-beam patterned biphenylthiol SAMs results in the fabrication of monomolecular pattern by selective thermal desorption. The reported results are not limited to the studied model system but can be extended to other aromatic SAM. One of the SAMs applications is the protein adsorption. We have introduced a methodology for the fabrication of protein chips based on the combination of electron beam lithography, molecular self-assembly principles, and biochemical tweezers for highly specific affinity capturing of His-tagged proteins. The functionality of the protein chips has been demonstrated by specific, homogeneous, oriented and reversible immobilization of His_6-tagged proteins. The high affinity of the protein arrays is achieved by utilization of multivalent interactions in NTA/His-tag pairs. Since electron beam lithography is suitable to the fabrication of SAM nanostructures with lateral dimensions down to 10 nm, in outlook we suggest that this concept can be further developed for the function immobilization structured proteins arrays on solid substrates down to single molecular resolution.