Real-time detection of bacteria spores using a QCM based immunosensor

In this paper we present evidence of detection of B. subtilis (non-pathogene models for B. anthracis) spores using a real-time, dual QCM (quartz crystal microbalance) immuno-sensing system. Device sensitivity is achieved through the use of a 10 MHz AT-cut quartz crystal operating in an enclosed flowcell. Specificity is maintained through the use of an immuno-sensing layer consisting of monoclonal antibodies specific to a single Bacillus species. The fidelity of both sensing parameters is ensured by the presence in our system of a reference device coated with an antibody that is not specific for the target antigen. Associating the QCM response signature with the specific binding of a particular species of Bacillus spore to an antibody has implications for future identification of pathogenic endospores such as B. anthracis.