An implantable biosensor may be placed subcutaneously to monitor the concentration of an analyte in a body fluid. The biosensor may include an electrochemical cell and an antenna. The components of the biosensor, including the electrochemical cell and the antenna, may be disposed on a same substrate. The electrochemical cell may include multiple electrodes for performing electrochemical measurements that include a first measurement of the analyte concentration in the body fluid, a second measurement of a background interference present in the body fluid, and a third measurement of a pH level within the body fluid. The antenna may receive, from a transceiver, radio frequency (RF) waves for wirelessly powering the implantable biosensor. The antenna may further transmit, back to the transceiver, a backscatter signal encoding a result of the electrochemical measurements.