title: Nickel nanoparticle-doped paper as a bioactive scaffold for targeted and robust immobilization of functional proteins.
abstract: Cellulose-based materials are widely used in analytical chemistry as platforms for chromatographic and immunodiagnostic techniques. Due to its countless advantages (e.g., mechanical properties, three-dimensional structure, large surface to volume area, biocompatibility and biodegradability, and high industrial availability), paper has been rediscovered as a valuable substrate for sensors. Polymeric materials such as cellulosic paper present high protein capture ability, resulting in a large increase of detection signal and improved assay sensitivity. However, cellulose is a rather nonreactive material for direct chemical coupling. Aiming at developing an efficient method for controlled conjugation of cellulose-based materials with proteins, we devised and fabricated a hybrid scaffold based on the adsorption and in situ self-assembly of surface-oxidized Ni nanoparticles on filter paper, which serve as "docking sites" for the selective immobilization of proteins containing polyhistidine tags (His-tag). We demonstrate that the interaction between the nickel substrate and the His-tagged protein G is remarkably resilient toward chemicals at concentrations that quickly disrupt standard Ni-NTA and Ni-IDA complexes, so that this system can be used for applications in which a robust attachment is desired. The bioconjugation with His-tagged protein G allowed the binding of anti-Salmonella antibodies that mediated the immuno-capture of live and motile Salmonella bacteria. The versatility and biocompatibility of the nickel substrate were further demonstrated by enzymatic reactions.
authors.affiliation: Departamento de Química Física, Universidade de Vigo , 36310 Vigo, Spain.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Bodelón
authors.forename: Stefanos
authors.initials: S
authors.lastname: Mourdikoudis
authors.forename: Luis
authors.initials: L
authors.lastname: Yate
authors.forename: Isabel
authors.initials: I
authors.lastname: Pastoriza-Santos
authors.forename: Jorge
authors.initials: J
authors.lastname: Pérez-Juste
authors.forename: Luis M
authors.initials: LM
authors.lastname: Liz-Marzán
mesh_terms: D000327:Adsorption; D001665:Binding Sites; D001672:Biocompatible Materials / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry; D002845:Chromatography; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000378:metabolism; D006639:Histidine / Q000737:chemistry; D055767:Immobilized Proteins / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D036103:Nanotechnology / Q000379:methods*; D009532:Nickel / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D012475:Salmonella / Q000378:metabolism; D013499:Surface Properties
chemical_list: D001672:Biocompatible Materials; D055767:Immobilized Proteins; D011108:Polymers; C033223:polyhistidine; D006639:Histidine; D009532:Nickel; D002482:Cellulose