Detection of biological and chemical contaminants in food requires highly sensitive detectors. Electrochemical immunoassays and immunosensors, based on the antigen−antibody interaction, have recently attracted interest because of their high sensitivity and low cost.

Dianping Tang and co-workers, Fuzhou University, China, have developed an electrochemical immunoassay for the detection of staphylococcal enterotoxin B (SEB) which utilizes multiwalled carbon nanotubes doped with horseradish peroxidase. Anti-SEB antibodies were immobilized as capture and detection antibodies in a sandwich-type format. The use of the carbon nanotubes was shown to amplify the electrochemical response of the immunoassay. The method detected SEB in spiked food samples at levels ranging from 0.05−15 ng/mL with a low detection limit of 10 pg/mL SEB.

• Ultrasensitive Electrochemical Immunoassay of Staphylococcal Enterotoxin B in Food Using Enzyme-Nanosilica-Doped Carbon Nanotubes for Signal Amplification
  D. Tang, J. Tang, B. Su, G. Chen,
  J. Agric. Food Chem. 2010, 58.
  DOI: 10.1021/jf102326m