Abstract: A fluidic device for detecting a target molecule in a fluid sample comprising a blocking chamber in fluidic communication with a detection chamber forming a blocking-detection chamber pair, the blocking chamber provided with at least one reagent for binding a non-target molecule in the sample, the blocking chamber adapted to maintain at least a portion of the bound non-target molecule within the blocking chamber, the detection chamber comprising at least one reagent for binding a target-molecule such that the target-molecule may be detected. The device comprises a combination detection chamber adapted to receive at least one reagent for binding both target and non-target molecules such that the combination of target and non-target molecules may be detected by binding to a detector.