A mobile analyte monitoring system may include an implantable sensor and a reader device with an optical sensor. The implantable sensor may be implanted into the dermis of an animal, and may exhibit a color change in response to the presence of a target analyte or reaction product thereof. The reader device may be configured to capture an image of the implanted sensor and to determine the concentration of the target analyte based at least in part on the image. One or more portions of the implantable sensor or components thereof may be configured to facilitate calibration of the sensor, correction of an optical signal obtained from the sensor by a reader device to accommodate variations in the surrounding tissues, and/or calculation of a representative value by a reader device. The reader device may be a personal electronic device such as a cell phone, PDA, or personal computer.
