Patent ID: 6514772
Filing Date: 2003-02-04
Classification: B82Y,G01N,Y10T

Abstract:
A method of detecting a target in a biological sample comprising the steps of:(a) contacting a biological sample suspecting of containing a target for a selected ligand with a ligand-semiconductor nanoparticle to form a bound ligand-semiconductor nanoparticle-biological sample, said ligand-semiconductor nanoparticle comprising the selected ligand having conjugated thereto at least one semiconductor nanoparticle, wherein said semiconductor nanoparticle comprises: (i) an amino derivative of a polysaccharide having a molecular weight from approximately 3,000 to 3,000,000 Da, a size in diameter of less than approximately 150 nanometers, and a degree of substitution of total number of primary and secondary amino groups in the polysaccharide molecule ranging from 1/150 to 4/1; and ii) at least one nanoparticle of the formula: (X Y)n wherein X is selected from the group comprising Cd2+, Hg2+, and Zn2+ and combinations thereof, and Y is selected from the group comprising S2âˆ’, Se2âˆ’ and Te2âˆ’ and combinations thereof, and n=approximately 50 to 1000, wherein said nanoparticle is linked to said aminopolysaccharide;(b) exciting said bound semiconductor nanoparticle-biological sample with infrared to ultraviolet light to cause it to luminesce; and (c) detecting the luminescence signal, thereby detecting the presence of the target for a selected ligand in the biological sample.