A novel electrochemical biomimetic sensor for theophylline detection was proposed, which was based on the molecular recognition events with artificial receptors, followed by triggering the surface initiated polymerization (SI-ATRP) to amplify the signals. Electropolymerized molecularly imprinted polymer (E-MIP) using thiophene-3-acetic acid (3-ATT) as functional monomers and theophylline as templates was employed to generate molecular recognition sites and led to immobilization of initiator-conjugated theophylline on the electrode surface. SIATRP subsequently was triggered and the polymer growth was monitored directly by atomic force microscope (AFM) technology. Acrylamide (AM) as growing chain units which accumulated in situ provided excess amino groups for the attachment of electrochemical tag, Phenothiazine sodium sulfonate (PTZ-343), thus enhanced assay sensitivity. The developed sensor displaying the excellent electrochemical detection performance that has a detection limit of 1.1 x 10(-11) M for the dynamic range of 0.3 x 10(-10) to 0.3 x 10(-4) M. Notedly, compared to those sensors based on nature recognition events triggering polymerization-assisted amplification, the promising method has the advantages of low cost and good robustness.