Micro-nanoparticles magnetic trap: Toward high sensitivity and rapid microfluidic continuous flow enzyme immunoassay.
| Autor: | Guevara-Pantoja PE; Cinvestav-Monterrey, 66600 Apodaca, Nuevo León, Mexico., Sánchez-Domínguez M; Centro de Investigación en Materiales Avanzados, S.C. (CIMAV), Unidad Monterrey, Alianza Norte 202, Parque de Investigación e Innovación Tecnológica, Apodaca 66628, Nuevo León, Mexico., Caballero-Robledo GA; Cinvestav-Monterrey, 66600 Apodaca, Nuevo León, Mexico. |
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| Jazyk: | angličtina |
| Zdroj: | Biomicrofluidics [Biomicrofluidics] 2020 Jan 30; Vol. 14 (1), pp. 014111. Date of Electronic Publication: 2020 Jan 30 (Print Publication: 2020). |
| DOI: | 10.1063/1.5126027 |
| Abstrakt: | In this work, we developed a microfluidic system for immunoassays where we combined the use of magnetic nanoparticles as immunosupport, a microfluidic magnetic trap, and a fluorogenic substrate in continuous flow for detection which, together with the optimization of the functionalization of surfaces to minimize nonspecific interactions, resulted in a detection limit in the order of femtomolar and a total assay time of 40 min for antibiotin antibody detection. A magnetic trap made of carbonyl-iron microparticles packaged inside a 200 μ m square microchannel was used to immobilize and concentrate nanoparticles. We functionalized the surface of the iron microparticles with a silica-polyethylene glycol (PEG) shell to avoid corrosion and unspecific protein binding. A new one-step method was developed to coat acrylic microchannels with an organofunctional silane functionalized with PEG to minimize unspecific binding. A model immunoassay was performed using nanoparticles decorated with biotin to capture antibiotin rabbit Immunoglobulin G (IgG) as target primary antibody. The detection was made using antirabbit IgG labeled with the enzyme alkaline phosphatase as a secondary antibody, and we measured fluorescence with a fluorescence microscope. All steps of the immunoassay were performed inside the chip. A calibration curve was obtained in which a detection limit of 8 pg/ml of antibiotin antibody was quantified. The simplicity of the device and the fact that it is made of acrylic, which is compatible with mass production, make it ideal for Point-Of-Care applications. (Copyright © 2020 Author(s).) |
| Databáze: | MEDLINE |
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