Flow injection electrochemical enzyme immunoassay for theophylline using a protein A immunoreactor and p-aminophenyl phosphate-p-aminophenol as the detection system.
A competitive electrochemical enzyme immunoassay has been developed for the antiasthmatic drug theophylline, utilizing a controlled-pore glass-protein A immunoreactor and flow injection techniques. p-Aminophenyl phosphate, a substrate for alkaline phosphatase, has been used in this assay, and its hydrolysis product p-aminophenol was determined at +0.2 V versus the saturated calomel electrode. For each sample the antibody-protein A reaction takes place at near-neutral pH, and the complexes are eluted at acid pH. Serum theophylline has been determined by this method, and good relative standard deviations and percentage recoveries have been achieved.
Palmer
D A
DA
Department of Chemistry, Loughborough University of Technology, Leicestershire, UK.
Edmonds
T E
TE
Seare
N J
NJ
D000469:Alkaline Phosphatase; D000627:Aminophenols; D000814:Aniline Compounds; D004563:Electrochemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007124:Immunoenzyme Techniques; D009943:Organophosphorus Compounds; D013205:Staphylococcal Protein A; D013806:Theophylline / Q000097:blood*
D000627:Aminophenols; D000814:Aniline Compounds; D009943:Organophosphorus Compounds; D013205:Staphylococcal Protein A; C068798:4-aminophenylphosphate; D013806:Theophylline; D000469:Alkaline Phosphatase; C026729:4-aminophenol