Capillary electrochemical enzyme immunoassay (CEEI) for phenobarbital in serum.
A competitive heterogeneous capillary enzyme immunoassay with electrochemical detection has been developed for phenobarbital in serum. The oxidized primary antibody was attached covalently to the modified interior surface of a microcapillary (22 microl). The competition between analyte phenobarbital and alkaline phosphatase labeled phenobarbital for a limited number of antibody binding sites was complete in 1.5 h. The enzymatic product (p-aminophenol) from the catalytic conversion of the substrate (p-aminophenyl phosphate) was detected by amperometric flow injection analysis. The calibration curve for phenobarbital had a detection limit of 30 microg l(-1) (2.8 pmoles or 0.65 ng) and a range of 30-3000 microg l(-1). The assay could be used to determine the phenobarbital serum concentration in a 4 microl clinical serum sample without pretreatment.
Zhang
J
J
Department of Chemistry, University of Cincinnati, OH 45221-0172, USA.
Heineman
W R
WR
Halsall
H B
HB
D000906:Antibodies / Q000032:analysis / Q000276:immunology; D001667:Binding, Competitive; D002021:Buffers; D002138:Calibration; D004563:Electrochemistry; D019075:Electrophoresis, Capillary; D006801:Humans; D006868:Hydrolysis; D006993:Hypnotics and Sedatives / Q000097:blood*; D007124:Immunoenzyme Techniques; D007202:Indicators and Reagents; D010084:Oxidation-Reduction; D010634:Phenobarbital / Q000097:blood*; D013056:Spectrophotometry, Ultraviolet
D000906:Antibodies; D002021:Buffers; D006993:Hypnotics and Sedatives; D007202:Indicators and Reagents; D010634:Phenobarbital