Considerable evidence has indicated that lectins (adhesins) on bacterial surfaces play an important role in the initiation of infection by mediating bacterial adherence to epithelial cell, especially in the gastrointestinal and urinary tracts. Many bacteria express adhesins on their surfaces in the form of specialized organelles that seek and bind to cognate receptors on the surface of mucosal cells. Some of these specific receptors have been reported and many of them are carbohydrates in nature. We have explored the use of specific carbohydrate receptors for the functionalization of nanoparticles and demonstrated their binding specificities and their ability to mediate aggregations of targeted bacteria. Based on these binding specificities, here we report the development of adhensin-specific nanomechanical cantilever (microcantilever) biosensors for the detection of their targeted microorganisms.