A portable biosensor for detecting and quantifying a target molecule in a biological sample and method of use include a biosensor fabricated with a recognition layer with an imprinted polymer, an electrode electrically coupled to the recognition layer, and a logic circuit that may include a processor and non-transitory memory with computer executable instructions embedded thereon, wherein the imprinted polymer is shaped to have a profile that substantially matches a profile of the target molecule, such that the target molecule can form-fit and bind to the imprinted polymer, thus changing an electrical property of the polymer layer that may be detected to identify the presence of the target molecule.