Enzyme-mediated chemiluminescence

One widely used enzyme mediated chemiluminescence immunoassay uses the firefly enzyme luciferase that catalyzes the oxidation of o-Luciferin in the presence of ATP. o-luciferin, but not luciferin esters such as phosphates, is oxidized in the presence... 

Chemiluminescence. Chemiluminescence (262—265) is the emission of light duting an exothermic chemical reaction, generaUy as fluorescence. It often occurs ia oxidation processes, and enzyme-mediated bioluminescence has important analytical appHcations (241,262). Chemiluminescence analysis is highly specific and can reach ppb detection limits with relatively simple iastmmentation. Nitric oxide has been so analyzed from reaction with ozone (266—268), and ozone can be detected by the emission at 585 nm from reaction with ethylene. 

Methods based on chemiluminescent and bioluminescent labels are another area of nonisotopic immunoassays that continue to undergo active research. Most common approaches in this category are the competitive binding chemiluminescence immunoassays and the immunochemiluminometric assays. Chemiluminescence and heterogenous chemiluminescence immunoassays have been the subject of excellent reviews (91, 92). Detection in chemiluminescence immunoassays is based on either the direct monitoring of conjugated labels, such as luminol or acridinium ester, or the enzyme-mediated formation of luminescent products. Preparation of various derivatives of acridinium esters has been reported (93, 94), whereas a variety of enzyme labels including firefly or bacterial luciferase (70), horseradish peroxidase (86, 98), and alkaline phosphatase are commercially available. 

An indirect chemiluminescence immunoassay is an assay, with another component than the primary chemiluminescent emitter coupled to the antigen or antibody. This can be a cofactor or a catalyst or even a molecule capable of converting a non-chemiluminescent precursor to a chemiluminescent or potentially chemiluminescent species. Most indirect assays are enzyme mediated. 

Chemiluminescence (CL) is the emission of light, usually in the visible or near infrared spectral region, as a result of an excited electronic molecular state, formed in a chemical reaction, returning to the ground state. Bioluminescence (BL) is the same emission process but involves a biochemical process such as an enzyme-mediated reaction for excitation. Chemiluminescence is a relatively rare phenomenon because... 

Electrogenerated chemiluminescence Enzyme-linked immunosorbent assay Electrophoretically-mediated microanalysis Electroosmotic flow Eosine Y... 

Lipid hydroperoxides are also generated in singlet molecular oxygen mediated oxidations and by the action of enzymes such as lipoxygenases and cyclooxygenases. Chemiluminescence (CL) arising from lipid peroxidation has been used as a sensitive detector of oxidative stress both in vitro and in vivo . Several authors have attributed ultra-weak CL associated with lipid peroxidation to the radiative deactivation of O2 and to triplet-excited carbonyls (63, 72) (equations 35 and 36) " . It has been proposed that the latter emitters arise from the thermolysis of dioxetane intermediates (61, 62) (equation 35), endoperoxide (73) (equation 37) and annihilation of aUtoxyl, as well as peroxyl radicals ... 

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