Centre National De La Recherche Scientifique

Ecole Polytechnique

Cédric Bouzigues

Thierry Gacoin

Antigoni Alexandrou

Maximilian Richly

Pascal Preira

Jean-Pierre Boilot

Rabei Mohammedi

Mouna Abdesselem

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

A method which can be used to analyse oxidising species in a sample, including: placing the sample in contact with a first photoluminescent agent, and a second optically active agent, at least the first photoluminescent agent including nanoparticles doped with rare earth elements and being oxidisable, the luminescence of the first photoluminescent agent varying, at least at one first wavelength, with the amount of oxidising species, and the signal emitted by the second optically active agent being constant or varying, at least at one second wavelength other than the first wavelength, with the amount of oxidising species in a direction opposite to the luminescence of the first photoluminescent agent; energising the first and second agents in the sample; measuring the light intensity of the sample at least at the first and second wavelengths; and assessing the presence and/or the amount of oxidising species by interpreting the measured light intensities.

Method for detecting oxidising species

Growing community of inventors

Paris, France

Cédric Bouzigues