A method for the detection of analytes using resonant
mass sensors or sensor arrays comprises
frequency encoding each sensor element, acquiring a time-domain
resonance signal from the sensor or
sensor array as it is exposed to
analyte, detecting change in the frequency or resonant properties of each sensor element using a
Fourier transform or other
spectral analysis method, and classifying, identifying, and / or quantifying
analyte using an appropriate
data analysis procedure. Frequency encoded sensors or sensor arrays comprise sensor elements with
frequency domain resonance signals that can be uniquely identified under a defined range of operating conditions.
Frequency encoding can be realized either by fabricating individual sensor elements with unique resonant frequencies or by tuning or modifying identical resonant devices to unique frequencies by adding or removing
mass from individual sensor elements. The array of sensor elements comprises multiple resonant structures that may have identical or unique sensing
layers. The sensing
layers influence the sensor elements' response to
analyte. Time-domain
signal is acquired, typically in a single
data acquisition channel, and typically using either (1) a pulsed excitation followed by acquisition of the free oscillatory decay of the entire array or (2) a
rapid scan acquisition of
signal from the entire array in a direct or
heterodyne configuration.
Spectrum analysis of the
time domain data is typically accomplished with
Fourier transform analysis. The methods and sensor arrays of the invention enable rapid and sensitive analyte detection, classification and / or identification of complex mixtures and unknown compounds, and quantification of known analytes, using sensor element design and signal detection hardware that are robust, simple and low cost.