Rapid detection of Salmonella enteritidis by piezoelectric immunosensor

Abstract

Comparative testing of three different coatings for the immobilization of the anti-Salmonella enteritidis antibody onto piezoelectric (PZ) crystals with gold, silver and palladium electrodes was done. In terms of stability, simplicity and magnitude of the frequency change caused by antibody binding to the coating, polyethyleneimine film gave the better results for the immobilization of antibody as compared with the (γ-aminopropyl)trimethoxysilane 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 rapid detection of Salmonella enteritidis was successfully performed using the antibody-modified PZ immunosensor. A detection limit of 1 × 105 cells/ml and an assay time of 35 min were achieved. © 2001 Elsevier Science B.V.