The performance and limitations of these sensors are often pre-evaluated or post-evaluated by recording calibration curves that relate the current intensity of the sensor to the concentration of the target analyte in a series of bulk test solutions. This is perfectly fine whenever these sensors are intended to be used to study the compositions of bulk solutions whose concentrations may vary slowly provided they remain homogeneous around the sensor. Indeed, the recorded calibration curves feature intrinsic characteristics of the sensors when used under such conditions. However, nowadays, these highly miniaturized sensors are more often designed to detect and quantify transient releases of analytes under in vivo or ex vivo conditions . Then, the usual evaluations of the sensors responses through calibration curves as often adopted in the literature, can lead to significant errors because the diffusional constraints during the detection are then highly different from those prevailing in steady homogeneous bulk solutions.