Immunosensor based on ink printed electrode for staphylococcal enterotoxin detection

Staphylococcal enterotoxin is one of the more aggressive enterotoxins produced by Staphylococcus aureus strains and it is a common cause of food poisoning. Analytical methods that are sensitive, low cost and easy to use are needed to evaluate the food quality. This work describes the development of a label free immunosensor based on screen-printed AuNPs/carbon and the characterization of its analytical response for staphylococcal enterotoxin B (SEB) detection. The biosensor was constructed from self-assembled monolayer of thiols and protein A for the oriented immobilization of the polyclonal antibodies against SEB. As electrons mediator, potassium ferrocyanide was used. The electrochemical detection was direct with the parameters following: -0.2 to 0.6 V with the pulse amplitude of 0.075 V and the pulse width of 75 ms. The immunosensor showed detection and quantification limits of 0.4 µg mL-1 and 1.6 µg mL-1,respectively. The immunosensor showed quite satisfactory performance in contaminated and non-contaminated cheese samples