title: Fabrication and characterization of a chemically oxidized-nanostructured porous silicon based biosensor implementing orienting protein A.
abstract: Nanostructured porous silicon (PSi) elicits as a very attractive material for future biosensing systems due to its high surface area, biocompatibility and well-established fabrication methods. In order to engineer its performance as a biosensor transducer platform, the density of immunoglobulins properly immobilized and oriented onto the surface needs to be optimized. In this work we fabricated and characterized a novel biosensing system focusing on the improvement of the biofunctionalization cascade. The system consists on a chemically oxidized PSi platform derivatized with 3-aminopropyltriethoxysilane (APTS) that is coupled to Staphylococcus protein A (SpA). The chemical oxidation has previously demonstrated to enhance the biofunctionalization process and here "by implementing SpA" a molecularly oriented immunosensor is achieved. The biosensor system is characterized in terms of its chemical composition, wettability and optical reflectance. Finally, this system is successfully exploited to develop a biosensor for detecting asymmetric dimethylarginine (ADMA), an endogenous molecule involved in cardiovascular diseases. Therefore, this work is relevant from the point of view of design and optimization of the biomolecular immobilization cascade on PSi surfaces with the added value of contribution to the development of new assays for detecting ADMA with a view on prevention of cardiovascular diseases.
authors.affiliation: Department of Applied Physics, Universidad Autónoma de Madrid, Madrid, Spain; Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain. Electronic address: nelson.naveas@estudiante.uam.es.
authors.forename: Nelson
authors.initials: N
authors.lastname: Naveas
authors.affiliation: Department of Applied Physics, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Jacobo
authors.initials: J
authors.lastname: Hernandez-Montelongo
authors.affiliation: Department of Applied Physics, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Ruth
authors.initials: R
authors.lastname: Pulido
authors.affiliation: Department of Applied Physics, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Vicente
authors.initials: V
authors.lastname: Torres-Costa
authors.affiliation: Department of Applied Physics, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Raúl
authors.initials: R
authors.lastname: Villanueva-Guerrero
authors.affiliation: Department of Molecular Biology, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Josefa
authors.initials: J
authors.lastname: Predestinación García Ruiz
authors.affiliation: Department of Applied Physics, Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: Manso-Silván
mesh_terms: D001120:Arginine / Q000031:analogs & derivatives / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D015374:Biosensing Techniques / Q000379:methods*; D007136:Immunoglobulins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D056951:Photoelectron Spectroscopy; D016062:Porosity; D012825:Silicon / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013205:Staphylococcal Protein A / Q000378:metabolism*; D014867:Water / Q000737:chemistry
chemical_list: D015415:Biomarkers; D007136:Immunoglobulins; D013205:Staphylococcal Protein A; C487735:dimethylarginine; D014867:Water; D001120:Arginine; D012825:Silicon
keywords: ADMA detection; Biofunctionalization; Biosensing; Porous silicon; Protein A; Protein immobilization