Development of an amperometric immunosensor for detection of staphylococcal enterotoxin type A in cheese.
This paper reports a novel electrochemical immunosensor for the sensitive detection of staphylococcal enterotoxin A (SEA) based on self-assembly monolayer (SAM) and protein A immobilization on gold electrode. Three different methods of protein A immobilization were tested: physical adsorption, cross-linking using glutaraldehyde and covalent binding after activation with N-hydroxysuccinimide (NHS)/N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) on cysteamine-modified gold electrode. The EDC/NHS method for protein A immobilization was selected to lead development of the biosensor. The coating steps of the surface modification were characterized by cyclic voltammetry and the biosensor response by chronoamperometry. The advantages of the immunosensor were exposed in its high sensitivity and specificity. The proposed amperometric immunosensor was successfully used for determination of SEA in contaminated and non-contaminated cheese samples with excellent responses.
Department of Chemistry, State University of Ceará, Av. Paranjana, 1700, Fortaleza-CE, Brazil.
Maria Gardenny Ribeiro
MG
Pimenta-Martins
Roselayne Ferro
RF
Furtado
Luiz Guilherme Dias
LG
Heneine
Ricardo Souza
RS
Dias
Maria de Fátima
Mde F
Borges
Carlucio Roberto
CR
Alves
D015374:Biosensing Techniques / Q000379:methods*; D002611:Cheese / Q000032:analysis*; D055664:Electrochemical Techniques / Q000379:methods*; D004768:Enterotoxins / Q000032:analysis* / Q000276:immunology; D012680:Sensitivity and Specificity; D013205:Staphylococcal Protein A / Q000276:immunology / Q000378:metabolism
D004768:Enterotoxins; D013205:Staphylococcal Protein A; C026066:enterotoxin A, Staphylococcal