Piezoelectric crystal for sensing bacteria by immobilizing antibodies on divinylsulphone activated poly-m-aminophenol film

A polymer sorbent formed at the surface of gold-plated piezoelectric crystal by anodic oxidation of m-aminophenol was investigated by voltammetric, FTIR techniques for antibody coupling after activation by divinylsulphone. A novel film with increased capacity for immobilizing antibodies was obtained using phloroglucinol to modify poly-m-aminophenol via divinylsulphone. Compared with the dip-coating methods using polyethylenimine and (γ-aminopropyl)trimethoxysilane, this new technique gave more reproducible results for the immobilization of antibody from sample to sample due to the improved homogeneity and reproducibility of the coating. With present modification method, a piezoelectric immunosensor was developed for the detection of Salmonella enteritidis. A detection limit of 1×105 cells ml−1 and an assay time of 25 min were achieved.