Diamond like carbon (DLC) has an atomically-smooth surface that can be deposited on high-surface area substrata and functionalized with reactive chemical groups, providing an ideal substrate for protein immobilization. A synthetic sequence is described involving deposition and hydrogenation of DLC followed by chemical functionalization. These functional groups are reacted with amines on proteins causing covalent immobilization on contact. Covalent functionalization of silicon surfaces by electrografting method and subsequent immobilization of bovine serum albumin (BSA). Our intent was to immobilize proteins on the surface of DLC substrate in a site-directed manner while retaining structure and native biological function and optimization for biosensing. Raman measurements confirm the presence of these surface functional groups and FTIR confirms covalent protein immobilization. Immobilization of BSA onto Silicon surfaces was also verified using FTIR of silicon Silicon surfaces, solution-phase fluorescence. Atomic force microscopy (AFM) of immobilized proteins is reproducible because proteins do not move as a result of interactions with the AFM probe-tip, thus providing an advantage over Silicon substrata typically used in AFM studies of protein.
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