Protein photoimmobilizations on the surface of quartz glass simply mediated by benzophenone

In this paper, photoinduced protein immobilizations on quartz glass slides utilizing benzophenone as photoinitiator without any photoactive group derivatizations involved were developed. Three different methods mediated by benzophenone were investigated, including protein photo-attachment onto untreated glass surface, protein attachment onto glass surface by reacting with pre-photografted maleic anhydride, and protein photo-attachment onto alkylamino silane functionalized glass surface, respectively. Protein immobilizations were characterized by fluorescence microscopy and atomic force microscopy. The preservation of biological activity after protein photo-attachments was confirmed by immunoassays. Area-defined protein immobilization was also primarily investigated. Comparative studies demonstrated that in respect of immobilization density, coverage homogeneities and photo-localization, protein photocoupling to amino-terminated quartz glass surfaces remarkably outperformed other photoinduced methods, as well as one kind of 3-(triethoxysilyl) propyl isocyanate chemical protein immobilization. The feasibility of this protein photo-immobilization on silicon-based materials is promising for widespread application because of its simplicity and effectiveness.