Adhesin-Specific Nanomechanical Cantilever Biosensors for Detection of Microorganisms

Lectins (adhesins) on bacterial surfaces play important roles in infection by mediating bacterial adherence to host cell surfaces via their cognate receptors. We have explored the use of $α$-D-mannose receptors as capturing agents for the detection of Escherichia coli using a microcantilever and have demonstrated that E. coli ORN178, which expresses normal type-1 pili, can interact with microcantilevers functionalized with $α$-D-mannose and can cause shifts in its resonance frequencies. Although E. coli ORN208, which expresses abnormal pili, binds poorly to $α$-D-mannose on the nitrocellulose membrane of a FAST slide, it did cause a detectable shift in resonance frequency when interacting with the $α$-D-mannose functionalized microcantilevers.