title: A novel approach for osteocalcin detection by competitive ELISA using porous silicon as a substrate.
abstract: In this study, porous silicon (PSi) was utilized instead of prevalent polystyrene platforms, and its capability in biomolecule screening was examined. Here, two types of porous structure, macroporous silicon (Macro-PSi) and mesoporous silicon (Meso-PSi), were produced on silicon wafers by electrochemical etching using different electrolytes. Moreover, both kinds of fresh and oxidized PSi samples were investigated. Next, osteocalcin as a biomarker of the bone formation process was used as a model biomarker, and the colorimetric detection was performed by competitive enzyme-linked immunosorbent assay (ELISA). Both Macro-PSi and Meso-PSi substrates in the oxidized state, specifically the Meso-porous structure, were reported to have higher surface area to volume ratio, more capacitance of surface-antigen interaction, and more ability to capture antigen in comparison with the prevalent platforms. Moreover, the optical density signal of osteocalcin detected by the ELISA technique was notably higher than the common platforms. Based on the findings of this study, PSi can potentially be used in the ELISA to achieve better results and consequently more sensitivity. A further asset of incorporating such a nanometer structure in the ELISA technique is that the system response to analyte concentration could be maintained by consuming lower monoclonal antibody (or antigen) and consequently reduces the cost of the experiment.
authors: Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran.
authors: Fereshteh
authors: F
authors: Rahimi
authors: Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran.
authors: Javad
authors: J
authors: Mohammadnejad Arough
authors: Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran.
authors: Mona
authors: M
authors: Yaghoobi
authors: Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran.
authors: Hadi
authors: H
authors: Davoodi
authors: Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran.
authors: Fatemeh
authors: F
authors: Sepehri
authors: Department of Life Science Engineering, Faculty of New Sciences & Technologies, University of Tehran, Tehran, Iran.
authors: Masood
authors: M
authors: Amirabadizadeh
mesh_terms: D015415:Biomarkers / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D015675:Osteocalcin / Q000032:analysis*; D010316:Particle Size; D016062:Porosity; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D015415:Biomarkers; D015675:Osteocalcin; D012825:Silicon
keywords: competitive ELISA; osteocalcin detection; porous silicon