An analyte sensor is disclosed that comprises:a light source arranged for emitting light to a probea detector arranged to receive fluorescence light emitted from said probe in response to the light incident from the light source, and to generate an output signal anda signal processor arranged to determine information related to the presence of an analyte at the probe based on at least the output signal of the detector,wherein the probe comprises nano-particles comprising fluorescent material for which the fluorescence changes in response to the presence of analyte.
