Luminescent oxygen channeling immunoassay: measurement of particle binding kinetics by chemiluminescence.
A method for monitoring formation of latex particle pairs by chemiluminescence is described. Molecular oxygen is excited by a photosensitizer and an antenna dye that are dissolved in one of the particles. 1 delta gO2 diffuses to the second particle and initiates a high quantum yield chemiluminescent reaction of an olefin that is dissolved in it. The efficiency of 1 delta gO2 transfer between particles is approximately 3.5%. The technique permits real-time measurement of particle binding kinetics. Second-order rate constants increase with the number of receptor binding sites on the particles and approach diffusion control. By using antibody-coated particles, a homogeneous immunoassay capable of detecting approximately 4 amol of thyroid-stimulating hormone in 12 min was demonstrated. Single molecules of analyte produce particle heterodimers that are detected even when no larger aggregates are formed.
Ullman
E F
EF
Research Department, Syva Company, Palo Alto, CA 94303.
Kirakossian
H
H
Singh
S
S
Wu
Z P
ZP
Irvin
B R
BR
Pease
J S
JS
Switchenko
A C
AC
Irvine
J D
JD
Dafforn
A
A
Skold
C N
CN
D000937:Antigen-Antibody Reactions; D004077:Digoxin / Q000276:immunology; D007840:Latex / Q000737:chemistry*; D008163:Luminescent Measurements; D008863:Microspheres; D010100:Oxygen / Q000737:chemistry*; D013972:Thyrotropin / Q000032:analysis* / Q000737:chemistry
D007840:Latex; D004077:Digoxin; D013972:Thyrotropin; D010100:Oxygen