A method of obtaining a drift-corrected normalized electrochemical signal output, comprising by use of an electrochemical sensor, wherein the electrochemical sensor comprises a working electrode functionalized with a plurality of recognition elements wherein each recognition element is capable of selectively binding one or more target species , wherein each recognition element is functionalized with a first sensing redox reporter , wherein binding of the target species to the recognition element causes a detectable change in the charge transfer between the sensing redox reporter and the electrode , wherein each recognition element is functionalized with a second reference redox reporter in proximity to the electrode, wherein binding of the target species to the recognition element does not affect the charge transfer between the reference redox reporter and the electrode ; exposing the electrochemical sensor to a calibration sample of known target concentration and measuring both a sensing signal and a reference signal; exposing the electrochemical sensor to a sample of unknown target concentration and measuring both a sensing signal and a reference signal; calculating a normalized sensing signal, which is a ratio between the sensing signal measured in the sample of unknown target concentration and the sensing signal measured in the sample of known target concentration; calculating a normalized reference signal, which is a ratio between the reference signal measured in the sample of unknown target concentration and the reference signal measured in the sample of known concentration; subtracting the normalized reference signal, which is indicative of drift, from the normalized sensing signal, which is indicative of both drift and target binding; wherein the difference comprises a drift-corrected normalized signal responsive only to target induced binding. by use of an electrochemical sensor, wherein the electrochemical sensor comprises a working electrode functionalized with a plurality of recognition elements wherein each recognition element is capable of selectively binding one or more target species , wherein each recognition element is functionalized with a first sensing redox reporter , wherein binding of the target species to the recognition element causes a detectable change in the charge transfer between the sensing redox reporter and the electrode , wherein each recognition element is functionalized with a second reference redox reporter in proximity to the electrode, wherein binding of the target species to the recognition element does not affect the charge transfer between the reference redox reporter and the electrode ; exposing the electrochemical sensor to a calibration sample of known target concentration and measuring both a sensing signal and a reference signal; exposing the electrochemical sensor to a sample of unknown target concentration and measuring both a sensing signal and a reference signal; calculating a normalized sensing signal, which is a ratio between the sensing signal measured in the sample of unknown target concentration and the sensing signal measured in the sample of known target concentration; calculating a normalized reference signal, which is a ratio between the reference signal measured in the sample of unknown target concentration and the reference signal measured in the sample of known concentration; subtracting the normalized reference signal, which is indicative of drift, from the normalized sensing signal, which is indicative of both drift and target binding; wherein the difference comprises a drift-corrected normalized signal responsive only to target induced binding. <EOS>