Dynamic response of polysilicon microcantilevers to enzymatic hydrolysis of urea

Micromolar levels of urea [1–20 mM] on surface micromachined polysilicon cantilever beams immobilized with the enzyme urease was studied. Urea hydrolyses to ammonia and carbon dioxide which are volatile in nature. Monitoring the change in resonance frequency of a urease immobilized cantilever beam during the course of urea hydrolysis, mediated by the immobilized enzyme can give us information on the reaction rates. The change in the resonance frequency of the cantilever beams as a result of urea hydrolysis was measured using Doppler Vibrometry. The reaction kinetics of the enzyme urease was studied by analyzing the dynamic response of the enzyme immobilized microcantilevers for various concentrations of urea.