Fluctuations of the mass adsorbed on microcantilever sensor surface in liquid-phase chemical and biochemical detection

We present a simple mathematical model of adsorbed mass fluctuations in microcantilever sensors operating in liquids, taking into account the effects of the transfer process of analyte molecules from a solution to the sensor surface. Using the derived expressions the analysis is performed in order to estimate the influence of mass transfer on the equilibrium fluctuations of the measured signal. The results show that mass transfer significantly influences the spectrum of fluctuations. The theory is useful for determination of limiting performances of cantilever sensors and for characterization of molecular binding-unbinding interactions using measured fluctuations in the sensor’s signal.

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► A theory of adsorbed mass fluctuations in microcantilever sensors used in liquids.
► The first quantitative analysis of the mass transfer influence on fluctuations.
► The mass transfer significantly influences the fluctuations spectrum.
► The presented theory is important for determination of sensor’s limiting performance.
► Useful for development of detection methods based on fluctuations spectrum analysis.