title: Electrogenerated chemiluminescence. 83. Immunoassay of human C-reactive protein by using Ru(bpy)3(2+)-encapsulated liposomes as labels.
abstract: Liposomes ( approximately 100-nm diameter) containing Ru(bpy)32+ (bpy = 2,2'-bipyridine) were prepared as an electrogenerated chemiluminescent (ECL) tag for a sandwich-type immunoassay of human C-reactive protein (CRP). Polyclonal human CRP antibodies were introduced onto liposomes and magnetic beads through biotin-streptavidin interaction. The antigen-antibody conjugates formed on addition of a CRP-containing sample were separated from unreacted species magnetically. Addition of 0.1 M tri-n-propylamine and 0.1 M phosphate buffer (pH 7.6) containing 0.1 M NaCl and 1% (v/v) Triton X-100 caused liberation of the Ru(bpy)32+ from the liposome. ECL obtained in this medium showed a detection limit of 100 ng/mL for human CRP with good linearity of ECL intensity versus antigen concentration over the range 100 ng/mL-10 microg/mL.
authors.affiliation: Department of Chemistry and Biochemistry, University of Texas, 1 University Station, A5300, Austin, Texas 78712, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhan
authors.forename: Allen J
authors.initials: AJ
authors.lastname: Bard
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives / Q000737:chemistry; D000906:Antibodies / Q000737:chemistry; D002097:C-Reactive Protein / Q000032:analysis* / Q000276:immunology; D002214:Capsules / Q000737:chemistry; D056831:Coordination Complexes; D004560:Electricity; D006801:Humans; D007118:Immunoassay; D008081:Liposomes / Q000737:chemistry; D049449:Luminescence; D008163:Luminescent Measurements; D008280:Magnetics; D008863:Microspheres; D012680:Sensitivity and Specificity; D017975:Ruthenium Compounds
chemical_list: D015082:2,2'-Dipyridyl; D000906:Antibodies; D002097:C-Reactive Protein; D002214:Capsules; D056831:Coordination Complexes; D008081:Liposomes; C547232:tris(2,2-bipyridine)-ruthenium(II); D017975:Ruthenium Compounds