Rapid detection of Salmonella enteritidis by piezoelectric immunosensor

Comparative testing of three different coatings for the immobilization of t he anti-Salmonella enteritidis antibody onto piezoelectric (PZ) crystals wi th gold, silver and palladium electrodes was done. In terms of stability, s implicity and magnitude of the frequency change caused by antibody binding to the coating, polyethyleneimine film gave the better results for the immo bilization of antibody as compared with the (gamma -aminopropyl)trimethoxys ilane film or the self-assembled monolayer of 3-mercaptopropionic acid. To reduce the production cost, the small-sized crystal with silver electrodes was used to fabricate the disposable antibody-modified PZ transducer. The r apid detection of Salmonella enteritidis was successfully performed using t he antibody-modified PZ immunosensor. A detection limit of 1 x 10(5) cells/ ml and an assay time of 35 min were achieved. (C) 2001 Elsevier Science B.V . All rights reserved.