A method for determining a diffusion feature of a fluidic sample using redox reactions in an electrochemical cell that has at least two electrodes, wherein the first electrode has at least one redox mediator at its surface or in close vicinity of its surface, and the second electrode has an electrode surface free of the redox mediator(s) in the beginning of a test, the method comprising: applying an electric potential to a fluidic sample in the electrochemical cell to initiate redox reactions at the two electrode surfaces； measuring current associated with the applied potential as a function of time, and using a measurement point on a transient part of the measured current at or after a turning point and its associated time to determine the diffusion feature.本發明提供一種用於在具有至少兩個電極之電化電池中使用氧化還原反應來判斷流體樣本之擴散特徵的方法，其中在測試開始時，第一電極在其表面處或緊鄰其表面處具有至少一種氧化還原介質，且第二電極具有不含該(等)氧化還原介質之電極表面，該方法包含：在該電化電池中向流體樣本施加電位以在該兩個電極表面處引發氧化還原反應；量測與所施加電位相關聯之電流隨時間的變化，及使用在轉折點處或轉折點之後所量測電流之暫態部分的量測點及其關聯時間來判斷該擴散特徵。
