A method for enhancing the detection sensitivity of a piezoelectric microcantilever sensor. The method may involve providing a piezoelectric microcantilever and inducing a change in the Young's modulus during detection of a species of interest. The change in the Young's modulus may be induced or enhanced by the application of a DC bias electric field to the piezoelectric layer that enhances non-180° polarization domain switching of the piezoelectric layer. The change in the Young's modulus may also result from binding of the species of interest to the piezoelectric microcantilever sensor or a combination of binding and application of a DC bias electric field Significantly enhanced detection sensitivity results from the changed Young's modulus of the piezoelectric layer.