A system, comprising: functionalized particles, wherein the functionalized particles are configured to interact with one or more target analytes present in an environment; a detector positioned in proximity to the environment and configured to detect a response signal transmitted from the environment, wherein the response signal includes a background signal and an analyte response signal indicative of interaction of the one or more target analytes with the functionalized particles; magnetic particles; characterized in that the system further comprises: a magnetic field source positioned in proximity to the environment and configured to distribute the magnetic particles into a spatial arrangement in the environment such that the magnetic particles in the spatial arrangement are positioned in proximity to a surface of the environment nearest to the detector, wherein the spatial arrangement of the magnetic particles in the environment modulates the analyte response signal as functionalized particles in the environment flow past the spatial arrangement of magnetic particles, such that the analyte response signal is affected differently than the background signal, and such that a period of the modulated analyte response signal as detected is different than a period of the background signal as detected; and a processor configured to non-invasively detect the one or more target analytes by differentiating the analyte response signal from the background signal, based at least in part on modulation of the analyte response signal. functionalized particles, wherein the functionalized particles are configured to interact with one or more target analytes present in an environment; a detector positioned in proximity to the environment and configured to detect a response signal transmitted from the environment, wherein the response signal includes a background signal and an analyte response signal indicative of interaction of the one or more target analytes with the functionalized particles; magnetic particles; characterized in that the system further comprises: a magnetic field source positioned in proximity to the environment and configured to distribute the magnetic particles into a spatial arrangement in the environment such that the magnetic particles in the spatial arrangement are positioned in proximity to a surface of the environment nearest to the detector, wherein the spatial arrangement of the magnetic particles in the environment modulates the analyte response signal as functionalized particles in the environment flow past the spatial arrangement of magnetic particles, such that the analyte response signal is affected differently than the background signal, and such that a period of the modulated analyte response signal as detected is different than a period of the background signal as detected; and a processor configured to non-invasively detect the one or more target analytes by differentiating the analyte response signal from the background signal, based at least in part on modulation of the analyte response signal. a magnetic field source positioned in proximity to the environment and configured to distribute the magnetic particles into a spatial arrangement in the environment such that the magnetic particles in the spatial arrangement are positioned in proximity to a surface of the environment nearest to the detector, wherein the spatial arrangement of the magnetic particles in the environment modulates the analyte response signal as functionalized particles in the environment flow past the spatial arrangement of magnetic particles, such that the analyte response signal is affected differently than the background signal, and such that a period of the modulated analyte response signal as detected is different than a period of the background signal as detected; and a processor configured to non-invasively detect the one or more target analytes by differentiating the analyte response signal from the background signal, based at least in part on modulation of the analyte response signal.