• Open Access

Antibody-Capped Mesoporous Nanoscopic Materials: Design of a Probe for the Selective Chromo-Fluorogenic Detection of Finasteride

Authors

  • Dr. Estela Climent,

    1. Centro de Reconocimienro Molecular y Desarrollo Tecnológico (IDM), Unidad mixta Universidad Politécnica de Valencia Universidad de Valencia, Universidad Politécnica de Valencia, Departamento de Química, Camino de Vera s/n, 46022 Valencia (Spain)
    2. CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Campus Rio Ebro, 50018 Zaragoza (Spain)
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  • Prof. Ramón Martínez-Máñez,

    Corresponding author
    1. Centro de Reconocimienro Molecular y Desarrollo Tecnológico (IDM), Unidad mixta Universidad Politécnica de Valencia Universidad de Valencia, Universidad Politécnica de Valencia, Departamento de Química, Camino de Vera s/n, 46022 Valencia (Spain)
    2. CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Campus Rio Ebro, 50018 Zaragoza (Spain)
    • Centro de Reconocimienro Molecular y Desarrollo Tecnológico (IDM), Unidad mixta Universidad Politécnica de Valencia Universidad de Valencia, Universidad Politécnica de Valencia, Departamento de Química, Camino de Vera s/n, 46022 Valencia (Spain)
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  • Prof. Ángel Maquieira,

    Corresponding author
    1. Centro de Reconocimienro Molecular y Desarrollo Tecnológico (IDM), Unidad mixta Universidad Politécnica de Valencia Universidad de Valencia, Universidad Politécnica de Valencia, Departamento de Química, Camino de Vera s/n, 46022 Valencia (Spain)
    • Centro de Reconocimienro Molecular y Desarrollo Tecnológico (IDM), Unidad mixta Universidad Politécnica de Valencia Universidad de Valencia, Universidad Politécnica de Valencia, Departamento de Química, Camino de Vera s/n, 46022 Valencia (Spain)
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  • Dr. Félix Sancenón,

    1. Centro de Reconocimienro Molecular y Desarrollo Tecnológico (IDM), Unidad mixta Universidad Politécnica de Valencia Universidad de Valencia, Universidad Politécnica de Valencia, Departamento de Química, Camino de Vera s/n, 46022 Valencia (Spain)
    2. CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Campus Rio Ebro, 50018 Zaragoza (Spain)
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  • Dr. M. Dolores Marcos,

    1. Centro de Reconocimienro Molecular y Desarrollo Tecnológico (IDM), Unidad mixta Universidad Politécnica de Valencia Universidad de Valencia, Universidad Politécnica de Valencia, Departamento de Química, Camino de Vera s/n, 46022 Valencia (Spain)
    2. CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Campus Rio Ebro, 50018 Zaragoza (Spain)
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  • Dr. Eva M. Brun,

    1. Centro de Reconocimienro Molecular y Desarrollo Tecnológico (IDM), Unidad mixta Universidad Politécnica de Valencia Universidad de Valencia, Universidad Politécnica de Valencia, Departamento de Química, Camino de Vera s/n, 46022 Valencia (Spain)
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  • Dr. Juan Soto,

    1. Centro de Reconocimienro Molecular y Desarrollo Tecnológico (IDM), Unidad mixta Universidad Politécnica de Valencia Universidad de Valencia, Universidad Politécnica de Valencia, Departamento de Química, Camino de Vera s/n, 46022 Valencia (Spain)
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  • Prof. Pedro Amorós

    1. Institut de Ciència dels Materials (ICMUV), Universidad de Valencia, P.O. Box 2085, 46071 Valencia (Spain)
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Abstract

The synthesis of capped mesoporous silica nanoparticles (MSN) conjugated with an antibody (AB) as a gatekeeper has been carried out in order to obtain a delivery system able to release an entrapped cargo (dye) in the presence of a target molecule (antigen) to which the conjugated antibody binds selectively. In particular, MSN loaded with rhodamine B and functionalized on the external surface with a suitable derivative of N-(t-butyl)-3-oxo-(5α,17β)-4-aza-androst-1-ene-17-carboxamide (finasteride) have been prepared (S1). The addition of polyclonal antibodies against finasteride induced capping of the pores due to the interaction with the anchored hapten-like finasteride derivative to give a MSN–hapten–AB nanoparticle S1-AB. It was found that the addition of capped material S1-AB to water solutions containing finasteride resulted in displacement of the antibody, pore uncapping and entrapped-dye release. The response of the gated material is highly selective, and only finasteride, among other steroids, was able to induce a significant uncapping process. Compared with finasteride, the finasteride metabolite was able to release 17 % of the dye, whereas the exogen steroids testosterone, metenolone and 16-β-hydroxystanozolol only induced very little release of rhodamine B (lower than 10 %) from aqueous suspensions containing sensing solid S1-AB. A detection limit as low as 20 ppb was found for the fluorimetric detection of finasteride. In order to evaluate a possible application of the material for label-free detection of finasteride, the capped material was isolated and stored to give final sensing solid S1-AB-i. It was found to display a similar behavior towards finasteride as to that shown by freshly prepared S1-AB; even after a period of two months, no significant loss of selectivity or sensitivity was noted. Moreover, to study the application for the detection of finasteride in biological samples, this “aged” material, S1-AB-i, was tested using commercially available blank urine as matrix. Samples containing 70 and 90 % blank urine were spiked with a defined amount of finasteride, and the concentration was determined using capped S1-AB-i. Recovery ranges from 94 % to 118 % were reached.

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