Antibiotic immunosensing: determination of sulfathiazole in water and honey.
The development of two sensitive and selective immunosensors for sulfathiazole, using immunoreagents - haptens, polyclonal antibodies, enzyme conjugates - previously obtained and characterized, is presented. One of them is based on the competitive immunocomplex capture format making use of an immobilized protein A/G sorbent, while the other employs a restricted access support in a novel homogeneous-heterogeneous (HH) assay mode. Maximum sensitivity, achieved with a total assay time of 18min for the capture sensor, is traduced in a dynamic range from 0.4 to 24microgL(-1), with a lower limit of detection of 0.11microgL(-1), increasing to 1.2microgL(-1) when employing an accelerated capture assay protocol that yields a sampling rate of 7 cycles per hour. The HH sensor shows the fastest response, performing each whole assay in only 2min, with a limit of detection of 0.85 and a measurement interval of 3.9-181.0microgL(-1), and with no need of support regeneration. Immunosensors are selective for sufathiazole, and only sulfamethoxypyridazine, sulfamethizole and sulfapyridine show non-negligible cross-reactivity, the same as in ELISA batch immunoassay. The application of the developed systems to the analysis of water, with no sample treatment, as well as honey samples after solid-phase extraction, demonstrate the reliability of the immunosensing for the monitoring of this type of pollutants.
Jornet
Dolors
D
Instituto de Reconocimiento Molecular y Desarrollo Tecnológico, Universidad Politécnica de Valencia, Valencia, Spain.
González-Martínez
Miguel A
MA
Puchades
Rosa
R
Maquieira
Angel
A
D000900:Anti-Bacterial Agents / Q000032:analysis*; D015374:Biosensing Techniques; D002138:Calibration; D002623:Chemistry Techniques, Analytical; D002845:Chromatography / Q000379:methods; D006241:Haptens / Q000737:chemistry; D006722:Honey; D007118:Immunoassay / Q000379:methods*; D008956:Models, Chemical; D000077589:Sulfathiazole; D013432:Sulfathiazoles / Q000032:analysis*; D013449:Sulfonamides / Q000032:analysis; D013997:Time Factors; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
D000900:Anti-Bacterial Agents; D006241:Haptens; D013432:Sulfathiazoles; D013449:Sulfonamides; D014874:Water Pollutants, Chemical; D014867:Water; D000077589:Sulfathiazole