PACS 07.60.Hv; 78.30.Jv; 85.60.Me; 87.80.+s ;
Biochemical passivation of metal surfaces for sensor application: reactive annealing of polycrystalline gold films in hydrogen sulfide atmosphere
B. A. Snopok* , K. V. Kostyukevych, G.V. Beketov, S.A. Zinio, Yu. M. Shirshov, E.F. Venger
Institute of Semiconductor Physics, NAS Ukraine, 45, prospect Nauki, 03028, Kyiv, Ukraine
Palladin Institute of Biochemistry, NAS Ukraine, ul. Leontovicha 9, 03030, Kyiv, Ukraine
Abstract. The formation of AuxSy interfacial layer by reactive annealing of gold films in H2S atmosphere is investigated. This seems to be a technologically favorable technique for the large-scale and low-cost fabrication of nondestructive immobilization support for biological molecules. Formation of phases with different chemical functionality and surface topography as a function of reaction time was studied using Atomic Force Microscopy (AFM), Surface Plasmon Resonance (SPR) measurements and biomolecular interaction analysis (trypsin - Soybean Trypsin Inhibitor (STI) reaction). The results obtained confirm the classical two-step model for the sulfide phase formation during reactive annealing. This includes an intermediate formation of a dispersed phase of sulfur followed by its reconstruction to a close-packed sulfide layer. Adsorption of proteins onto a certain sulfide layer passes with retention of a native state of adsorbed molecules. The proposed strategy for formation of biochemical structures (gold/sulfide/proteins) on the surface of physical transducers opens a new way for design and development of novel artificial smart sensing systems. They not only maintain optimal functioning of bioreceptors but also are responsive to their environment.
Keywords: polycrystalline gold films, sulfide layers, biosensors, enzymes, soybean trypsin inhibitor, reactive annealing, smart sensing system, Atomic Force Microscopy, Surface Plasmon Resonance.