Centre National De La Recherche Scientifique

Ecole Polytechnique

Maximilian Richly

Thierry Gacoin

Antigoni Alexandrou

Cédric Bouzigues

Pascal Preira

Rabei Mohammedi

A process for ultrasensitive in vitro detection and/or quantification of a substance of interest in a sample is performed by detecting the luminescence emission by photoluminescent inorganic nanoparticles. The process includes (i) use of photoluminescent particles comprising a photoluminescent inorganic nanoparticle consisting of a crystalline matrix having at least 10rare-earth ions, and coupled to a targeting agent for the substance to be analyzed, under conditions conducive to their association with the sample substance to be analyzed; (ii) exciting the rare-earth ions of the particles by an illumination device having a power of at least 50 mW and an excitation intensity of at least 1 W/cm; (iii) detecting the luminescence emission by the particles after single-photon absorption; and (iv) determining the presence and/or concentration of the substance by interpreting said luminescence measurement. This process can be used for in vitro diagnostic purposes and as an in vitro diagnostic kit.

Ultra-sensitive detection method using photoluminescent particles

The present invention concerns a luminescent particle comprising a nanoparticle of formulaALnVO(PO)&#x2003;&#x2003;(I)in which A is selected from yttrium (Y), gadolinium (Gd), lanthanum (La), and mixtures thereof; Ln is selected from europium (Eu), dysprosium (Dy), samarium (Sm), neodymium (Nd), erbium (Er), ytterbium (Yb), and mixtures thereof; 0&#x3c;x&#x3c;1; and 0&#x2264;y&#x3c;1; characterized in that the nanoparticle on its surface has tetraalkylammonium cations in an amount such that said nanoparticle has a zeta potential, &#x3b6;, of less than or equal to &#x2212;28 mV in an aqueous medium with a pH&#x2265;5, more particularly with a pH&#x2265;5.5, and with an ionic conductivity &#x3e;100 &#x3bc;S&#xb7;cm. It also concerns a method for preparing such luminescent particles, a colloidal suspension of these particles, and the use thereof as a diagnostic agent, and also a diagnostic kit comprising such luminescent particles.

Luminescent particles based on rare earth elements and use thereof as a diagnostic agent

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Paris, France

Maximilian Richly