title: Study of Immobilization Procedure on Silver Nanolayers and Detection of Estrone with Diverged Beam Surface Plasmon Resonance (SPR) Imaging.
abstract: An immobilization protocol was developed to attach receptors on smooth silver thin films. Dense and packed 11-mercaptoundecanoic acid (11-MUA) was used to avoid uncontrolled sulfidization and harmful oxidation of silver nanolayers. N,N'-dicyclohexylcarbodiimide (DCC) and N-hydroxysuccinimide (NHS) were added to make the silver surfaces reactive. A comparative study was carried out with different immersion times of silver samples in 11-MUA solutions with different concentrations to find the optimum conditions for immobilization. The signals, during each step of the protocol, were analyzed with a refractometer based on the surface plasmon resonance (SPR) effect and luminescence techniques. Molecular interactions at the surfaces between the probe and target at the surface nanolayer shift the SPR signal, thus indicating the presence of the substance. To demonstrate specific biosensing, rabbit anti-estrone polyclonal immunoglobulin G (IgG) antibody was immobilized through a linker on 47 nm silver layer deposited on SF11 glass. At the final stage, the representative endocrine disruptor-estrone-was attached and detected in deionized water with a diverging beam SPR imaging sensor.
authors.affiliation: Electro-Optic Engineering Unit and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
authors.forename: Alina
authors.initials: A
authors.lastname: Karabchevsky
authors.affiliation: Environmental Engineering Unit, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
authors.forename: Lev
authors.initials: L
authors.lastname: Tsapovsky
authors.affiliation: Biotechnology Engineering, National Institute for Biotechnology in the Negev and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.|School of Materials Science and Engineering, Nanyang Technological University, 637722, Singapore.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Marks
authors.affiliation: Electro-Optic Engineering Unit and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.|School of Materials Science and Engineering, Nanyang Technological University, 637722, Singapore.
authors.forename: Ibrahim
authors.identifier: 0000-0002-1474-5412
authors.initials: I
authors.lastname: Abdulhalim
keywords: SPR imaging; endocrine disruptor; estrone; immobilization; optical immunosensor