title: Development of a sensitivity-improved immunoassay for the determination of carbaryl in food samples.
abstract: BACKGROUND
  With the aim of developing a highly sensitive immunoassay for carbaryl, a hapten which had high similarity to carbaryl was synthesised using a safer and more practical approach. After it was conjugated to horseradish peroxidase, direct competitive heterologous enzyme-linked immunosorbent assay (CD-ELISA) was optimised and characterised. The assay performance conditions were investigated in details. Enhanced chemiluminescence ELISA (ECL-ELISA) was also used in preliminary studies.
  
  
  RESULTS
  The assay obtained an IC(50) value (the concentration causing 50% inhibition) of 2 microg kg(-1), which was 12-fold more sensitive than previous results of homologous CD-ELISA. In ECL-ELISA, the IC(50) was further decreased 10-fold to 0.2 microg kg(-1). The CD-ELISA developed was applicable for broad conditions, and could be applied on various food samples with a more convenient pre-treatment. Average recoveries were in a range of 88.3-101.7%. The results correlated well with those obtained using high-performance liquid chromatography (HPLC) analysis (R(2) = 0.989).
  
  
  CONCLUSIONS
  The ELISA developed was a great improvement in the determination of carbaryl, showing that the immunoassay developed was a simple, rapid and efficient method that was reliable for the detection of carbaryl and suitable for rapid quantitative or qualitative determination in food samples.
authors.affiliation: Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Dong
authors.forename: Jingwei
authors.initials: J
authors.lastname: Sun
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.forename: Shuo
authors.initials: S
authors.lastname: Wang
mesh_terms: D001628:Beverages / Q000032:analysis; D012721:Carbaryl / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D004784:Environmental Monitoring; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D006241:Haptens; D006735:Horseradish Peroxidase; D020128:Inhibitory Concentration 50; D007306:Insecticides / Q000032:analysis*; D049449:Luminescence
chemical_list: D006241:Haptens; D007306:Insecticides; D006735:Horseradish Peroxidase; D012721:Carbaryl