A Versatile Near-Infrared Asymmetric Tricarbocyanine for Zinc Ion Sensing in Water

Authors

  • Guillermo O. Menéndez,

    1. CIHIDECAR-CONICET, Dpto. de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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  • Cecilia Samaniego López,

    1. CIHIDECAR-CONICET, Dpto. de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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  • Elizabeth A. Jares-Erijman,

    1. CIHIDECAR-CONICET, Dpto. de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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  • Carla C. Spagnuolo

    Corresponding author
    1. CIHIDECAR-CONICET, Dpto. de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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  • This article is part of the Special Issue dedicated to the memory of Elsa Abuin.

Abstract

We have synthesized a near-infrared emissive asymmetric tricarbocyanine conveniently functionalized to improve bioconjugation. The leading structure contains a versatile derivatization point at the meso position for facile radical-nucleophilic aromatic substitution. We have evaluated a DPEN (N,N-di(2-picolyl)ethylendiamine) derivative of this dye as a highly selective sensor for zinc (II) in aqueous medium, which performs in an appropriate sensitivity range for biological studies. The probe was successfully conjugated to a protein-ligand model with high affinity and specificity (biotin–streptavidin technology) rendering an excellent performance of sensing. In a general strategy to obtain sensitive probes combining fluorescent nanoparticles and molecular fluorophores, a preliminary design of a supramolecular assembly derived from the conjugation of the molecular sensor to quantum dots (QDs) was also investigated. The advantages and problems of FRET-based sensors are also discussed.

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