Tris(2,2'-bipyridine)ruthenium (II) as a peroxide-producing replacement for enzymes as chemical labels.
The concentration of the ruthenium-based label is determined from the rate of hydrogen peroxide production elicited by photolysis. Electron transfer quenching of the photoexcited label by methyl viologen (1,1'-dimethyl-4,4'bipyridinium dication, MV2+) and/or oxygen in the presence of EDTA generates hydrogen peroxide. Both flow injection and direct photolysis techniques were tested, with the latter showing better results. Direct photolysis is more sensitive, faster, requires only a 20 microliters sample volume, uses only 30 mW laser power and shows a smaller background. The presence of 5% normal human serum in the sample did not interfere with the measurements. Linear calibration curves were obtained in the nanomolar concentration range for goat antimouse antibody labeled with the ruthenium complex. The determination of membrane-surface-bound labeled IgG is accomplished by direct photolysis of a membrane that covers a platinum microelectrode.
Ismail
K Z
KZ
Department of Chemistry, University of Pittsburgh, Pennsylvania 15260.
Weber
S G
SG
D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000737:chemistry; D056831:Coordination Complexes; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007124:Immunoenzyme Techniques; D007202:Indicators and Reagents / Q000737:chemistry*; D010782:Photolysis; D017975:Ruthenium Compounds
D015082:2,2'-Dipyridyl; D056831:Coordination Complexes; D006861:Hydrogen Peroxide; D007202:Indicators and Reagents; C547232:tris(2,2-bipyridine)-ruthenium(II); D017975:Ruthenium Compounds