Immunosensors for pollutants working in organic media. Study of performances of different tracers with luminescent detection.
A comparative study of enzymatic and non-enzymatic labels combined with luminescence detection, developed for immunosensing of pesticide residues (carbaryl, 1-naphthol, irgarol 1051) in organic media, is presented. Peroxidase and alkaline phosphatase enzymes with fluorogenic (3-p-hydroxyphenylpropanoic acid) and luminogenic (AMPPD derivative) substrates, respectively, were assessed as enzymatic markers. As an alternative, terbium(III) chelate, with time-resolved fluorescence detection, was evaluated as a non-enzymatic label. The best sensitivity was achieved by use of alkaline phosphatase in an immunocomplex capture assay format (I (50) values 0.06, 0.27, and 7.45 microg L(-1) in buffer, 1:1 methanol-buffer, and methanol, respectively). Results were also good (I (50) 1.00 and 6.30 microg L(-1) for water and aqueous-organic mixture, respectively) for Tb(III) chelate in an immobilized conjugate assay format. Use of alkaline phosphatase label to measure carbaryl (100 ng L(-1)) in different spiked river water samples, after solid-phase extraction and analyte elution with an ethyl acetate-methanol mixture, resulted in recoveries ranging from 81 to 98%, with acceptable precision (CV 4-14%, n=4).
González-Martínez
M A
MA
Departamento Química, Universidad Politécnica de Valencia, 46022, Valencia, Spain.
Penalva
J
J
Rodríguez-Urbis
J C
JC
Brunet
E
E
Maquieira
A
A
Puchades
R
R
D000218:Adamantane / Q000031:analogs & derivatives / Q000737:chemistry; D002109:Caffeic Acids / Q000737:chemistry; D012721:Carbaryl / Q000737:chemistry; D002625:Chemistry, Organic / Q000379:methods*; D015386:Hazardous Substances / Q000032:analysis*; D007120:Immunochemistry / Q000379:methods*; D007202:Indicators and Reagents; D049449:Luminescence; D008956:Models, Chemical; D009284:Naphthols / Q000494:pharmacology; D009930:Organic Chemicals; D010544:Peroxidases / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D013725:Terbium / Q000494:pharmacology; D014227:Triazines / Q000494:pharmacology
D002109:Caffeic Acids; D015386:Hazardous Substances; D007202:Indicators and Reagents; D009284:Naphthols; D009930:Organic Chemicals; D014227:Triazines; D013725:Terbium; C000995:3,4-dihydroxyphenylpropionic acid; C061523:3-(2'-spiroadamantane)-4-methoxy-4-(3''-phosphoryloxy)phenyl-1,2-dioxetane; C103341:irgarol 1051; C029350:1-naphthol; D010544:Peroxidases; D000218:Adamantane; D012721:Carbaryl