Capillary action test using photoluminescent inorganic nanoparticles

An in vitro method for detecting and/or quantifying a biological or chemical substance of interest in a liquid sample, by a capillary action test using, as probes, photoluminescent inorganic nanoparticles of the following formula (II):

• Al1-xLnxVO4(1-y)(PO4)y (II)
• in which:
• A is selected from yttrium (Y), gadolinium (Gd), lanthanum (La), lutetium (Lu), and mixtures thereof;
• Ln is selected from europium (Eu), dysprosium (Dy), samarium (Sm), neodymium (Nd), erbium (Er), ytterbium (Yb), thulium (Tm), praseodymium (Pr), holmium (Ho) and mixtures thereof;
• 0<x<1;
• and
• 0≤y<1;
• said method employing detection of the luminescence, with an emission lifetime shorter than 100 ms, of the nanoparticles, after one-photon absorption, by excitation of the matrix at a wavelength less than or equal to 320 nm.

A capillary action test device, useful for detecting and/or quantifying a biological or chemical substance of interest in a liquid sample, said device comprising, as probes, photoluminescent inorganic nanoparticles of the following formula (II):

• A1-xLnxVO4(1-y)(PO4)y (II)
• in which:
• A is selected from yttrium (Y), gadolinium (Gd), lanthanum (La), lutetium (Lu), and mixtures thereof;
• Ln is selected from europium (Eu), dysprosium (Dy), samarium (Sm), neodymium (Nd), erbium (Er), ytterbium (Yb), thulium (Tm), praseodymium (Pr), holmium (Ho) and mixtures thereof;
• 0<x<1;
• and
• 0≤y<1;
• said nanoparticles being able to emit luminescence, with an emission lifetime shorter than 100 ms, after one-photon absorption, by excitation of the matrix at a wavelength less than or equal to 320 nm.

An in vitro diagnostic kit, comprising at least:

• a capillary action test device useful for detecting and/or quantifying a biological or chemical substance of interest in a liquid sample, said device comprising, as probes, photoluminescent inorganic nanoparticles of the following formula (II):
• A1-xLnxVO4(1-y)(PO4)y (II)
• in which:
• A is selected from yttrium (Y), gadolinium (Gd), lanthanum (La), lutetium (Lu), and mixtures thereof;
• Ln is selected from europium (Eu), dysprosium (Dy), samarium (Sm), neodymium (Nd), erbium (Er), ytterbium (Yb), thulium (Tm), praseodymium (Pr), holmium (Ho) and mixtures thereof;
• 0<x<1;
• and
• 0≤y<1;
• said nanoparticles being able to emit luminescence, with an emission lifetime shorter than 100 ms, after one-photon absorption, by excitation of the matrix at a wavelength less than or equal to 320 nm;
• and
• a device for detecting the luminescence generated by the probes immobilized at the level of the capillary action test device, at the end of the assay.