An electrochemical sensor for the determination of manganese (II) ion with high selectivity was developed by using modified glassy carbon electrode with a nanocomposite film containing immobilized Mn(II)-IIP particles abbreviated as Mn(II)-IIP/MWCNT/Chit/IL/GCE. The manipulation of IIP increases the selectivity of the sensor and the presence of MWCNT/Chit/IL provides significant enhancement of the electron transfer rate during redox reactions. The Mn(II)IIP-NPs were obtained by thermal polymerization of Methacrylic acid (the monomer), ethylene glycol dimethacrylate (cross-linker), 2,2'-azobisisobutyronitrile (chemical initiator), 1-(2-Pyridylazo)-2-naphthol (manganese-binding ligand), and manganese ions (template ion) in ethanol. The response of the constructed sensor was linear in the range of 2.0 to 9.0 mu M with a detection limit of 0.15 mu M and much higher sensitivity (130.5 nA mu M(-1)cm(-2)). The important parameters such as IIP amount, preconcentration potential and accumulation time were optimized to be 1.0 mg, ? 1.4 V and 120 s, respectively. The interference of different ionic species with the response of the sensor was also studied. The proposed sensor provides the important advantages of relative high sensitivity, excellent selectivity and operation convenience as well as low detection limit.