Disclosed is a sensor for measuring the amount of an analyte to be detected in human interstitial fluid, comprising a micro-cantilever sensing unit which includes: a first substrate; a micro-cantilever which is substantially in parallel with the first substrate and one end of which is supported onto the first substrate; a gold film formed onto at least one side of the micro-cantilever; a protein layer formed on the gold film, the protein layer being used to adsorb, at a surface thereof, the analyte to be detected in human interstitial fluid; a driving electrode provided on the first substrate; a micro-cantilever electrode which is provided on the first substrate at a position where the micro-cantilever is supported, and which is cooperated with the driving electrode so as to drive the micro-cantilever to produce resonance in a direction perpendicular to the first substrate; and a detecting electrode which is provided on the first substrate and which is cooperated with the micro-cantilever electrode so as to detect resonance frequency of the micro-cantilever. The present invention also relates to a fluid channel unit, a sensor system, and a method for measuring the amount of an analyte to be detected in human interstitial fluid.