Reagent for luminescence optical determination of an analyte
The invention relates to a reagent for carrying out assays in accordance with the FRET-principle, containing an acceptor dye as well as particles exhibiting a donor dye, whereby the donor dye and the acceptor dye are located in different chemical phases, the acceptor dye is provided as bound to the particles and the particles are essentially impermeable to the sample medium or to components of the sample medium affecting the luminescence characteristics of the donor dye. The invention furthermore relates to a method for the qualitative and/or quantitative determination of at least one analyte and/or component of a liquid measuring medium, comprising the addition of the reagent according to the invention to the measuring medium.
1. A reagent for qualitative and quantitative determination of at least one analyte in a liquid measuring medium in accordance with the FRET principle, wherein the reagent comprises
particles impermeable to the liquid measuring medium and comprising a donor dye, wherein the donor dye defines an emission spectrum;
an acceptor dye bound to the surface of the particles covalently, electrostatically, or adsorptively, wherein the acceptor dye defines an absorption spectrum; and
wherein the particles comprising the donor dye and the acceptor dye bound thereon are configured to be dispersed inside the liquid measuring medium, the donor dye being in sufficient spatial proximity to the acceptor dye to produce nonradiative energy transfer from molecules of the donor dye to molecules of the acceptor dye.
2. A reagent according to claim 1 , wherein the particles comprise at least one unplasticized polymer.
3. A reagent according to claim 2 , wherein the polymer is at least one of polyacryl nitrile, a derivative of polyacryl nitrile, PVC, and/or polyvinylidene chloride.
4. A method for the qualitative and/or quantitative determination of at least one analyte in a liquid measuring medium, comprising
adding a reagent of claim 1 to the measuring medium;
determining the luminescence characteristics of the donor dye wherein the luminescence characteristics include luminescence decay time, luminescence intensity, or both; and
inferring the analyte value of the liquid measuring medium from the luminescence characteristics of the donor dye.
5. A method according to claim 4 , wherein the method determines the pH-value of the liquid measuring medium.
6. The method of claim 4 , wherein the method determines at least one of the concentration or activity of an ion in the liquid measuring medium.
7. The method of 6 wherein the ion is Li + , Na + , K + , Mg ++ , Ca ++ or Cl.
8. The method of claim 4 wherein the liquid measuring medium is a body fluid.
9. A method for the qualitative and/or quantitative determination of at least one analyte in a liquid measuring medium comprising: adding a reagent of claim 1 to the measuring medium; and determining whether the acceptor is in complexed or noncomplexed form in order to determine the concentration of an ion in the liquid measuring medium, wherein a complexed acceptor form corresponds to a high ion concentration.
10. The method of claim 9 wherein the liquid measuring medium is a body fluid.