Detection of Group A Streptococcus and Model Protein Using Self-Excited PZT-Glass Microcantilever

A composite self-excited PZT-glass cantilever (4mm in length and 2mm width) was fabricated and used to measure attachment of model protein and a model pathogen. Key feature of the microcantilever is that its resonant frequency is dependent on its mass. The cantilever had a mass sensitivity of 5x10-11 g/Hz. The change in resonant frequency was measured as antibody, protein, reacts with the amine-derivatized sensing glass surface and pathogen, Group A Streptococcus, attaches to the antibody immobilized microcantilever. Very low pathogen concentration (640 bacteria/mL) was successfully detected, thus demonstrating the usefulness of the cantilever for detecting water-borne pathogens.