Enhancement of BSA Binding on Au Surfaces by calix[4]bisazacrown Monolayer

Effective investigation of biomolecular structure and function with chip-based modern instruments often requires reliable and steady attachment of designated biomolecules on substrate. Here, we investigated the formation of self-assembled monolayer (SAM) with a new calix[4]arene derivative containing bisazacrown ether at the lower rim (calix[4]bisazacrown) where ammonium moieties of proteins can mainly be interacted with. Immobilization process of protein using bovine serum albumin (BSA) on the Au surface modified with calix[4]bisazacrown monolyer as an artificial linker system was monitored by surface plasmon resonance (SPR) technique. The surface concentration of BSA calculated by the simulation of SPR experimental data was higher than that of a well-known similar commercial protein linker. These results can help in modeling and understanding of protein immobilization on solid surface as well as further development lab-on-a-chip (LOC) devices for biomedical diagnosis kit of certain protein related diseases as biomarkers.