EMISSION QUENCHING SENSORS

摘要

The present invention relates to a sensing instrument and method for measuring the concentration of an analyte. The sensing instrument includes: a sensing element including at least a first emissive indicator characterized by a bimolecular quenching rate constant kq, one or more fluorescence lifetimes tau o above a lowest lifetime tau oL, and capable of emitting analyte concentration dependent signals when exposed to an excitation signal in the presence of quencher; an excitation system which provides an amplitude modulated excitation signal at one or more radial modulation frequencies omega ; a detector; and a processor. The processor univariantly processes the detected signals and provides output signals representative of analyte concentration. The sensing element and/or excitation system are configured to enable the instrument to operate sufficiently within the condition [(kq[Q])2+ omega 2] tau o2>>1+2kq tau o[Q] such that a slope of the relationship between the concentration dependent parameter and analyte concentration is independent of tau o variability and/or heterogeneity for all analyte concentrations within the operating range and for all lifetimes tau o greater than tau oL.