Glucose biosensing using an enzyme-coated microcantilever

A microcantilever-based biosensor is described. The enzyme glucose oxidase was immobilized on a micromachined silicon cantilever containing a gold coating, such as those used for atomic force microscopy. Specific, quantifiable deflection of the derivatized cantilevers was observed in the presence of the appropriate analyte. An analysis of the reaction energetics and the expected thermal response of the cantilever indicates that cantilever deflection is not simply a result of reaction-generated heat. This deflection appears to result from surface induced stresses. The combination of a highly specific enzyme and the microcantilever platform provides a unique approach for quantifying enzyme substrates without the complication of sample labeling.