Polyelectrolyte nanoparticles based on terbium(III) complexes as sensors

Fluorescent nanoparticles have attracted great attention of researchers due to their potential use as probes and markers for medical and bioanalytical applications. Sensory properties and biocompatibility are obtained by design colloidal structures of the "core-shell". Our previous report introduces a simple and convenient synthetic method of obtaining colloid solutions of luminescent terbium complexes on the basis of the new calix[4]resorcinarenes bearing four 1,3-diketone groups at the upper rim [1]. The basis of the this approach is the reprecipitation of luminescent complexes from organic to aqueous solutions followed by a stabilization of the obtained colloids through an adsorption of polyelectrolytes onto hard templates.

The present work is devoted to study the sensing function of polyelectrolyte-coated colloids based on terbium(III) complexes with calix[4]resorcinarene cavitand bearing four 1,3-diketone groups at the upper rim. The Tb(III)-centered luminescent intensity remains high level at wide range of pH. Both colloidal and luminescent properties of the colloids are stable within one month at least due to the stability of the complex in the composition of the solid core and the presence of soft polyelectrolyte shell. The presence of substrates capable of binding to the chelate (fluoroquinolones, tetracycline and catechol derivatives) results in a quick and reproducible luminescent response with no detectable change in properties of the colloidal nanoparticles. The presence of the phase boundary in the core of the colloidal particles affects the ternary complexation process that results in selective response to a number of antibiotics and fluoroquinolone tetracycline antibiotics [2].

The reported study was funded according to the research project МК 4456.2015.3.

1. Shamsutdinova N.A., Podyachev S.N., Sudakova S.N., Mustafina A.R., Zairov R.R., Burilov V.A., Nizameev I.R., Rizvanov I.K., Syakaev V.V., Gabidullin B.M., Katsuba S.A., Gubaidullin A.T., Safiullin G.M., Dehaen W. A facile synthetic route to convert Tb(iii) complexes of novel tetra-1,3-diketone calix[4]resorcinarene into hydrophilic luminescent colloids // New Journal of Chemistry. 2014. V. 38. P. 4130-4140;

2. N. Shamsutdinova, R. Zairov, A. Mustafina, S. Podyachev, S. Sudakova, I. Nizameev, M. Kadirov, R. Amirov. Interfacial complex ability of hard polyelectrolyte-stabilized colloids based on Tb(III) complexes as a reason for substrate-induced luminescent response // Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2015. V.482. P. 231–240.