A novel flow injection chemiluminescence (CL) sensor for the determination of maleic hydrazide (MH) using molecularly imprinted polymer (MIP) as recognition element is reported. The MH-MIP was synthesized by thermal initiated polymerization in methanol, using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker in the maleic hydrazide template molecule. Molecular modeling was employed to simulate the possible recognition process of the MIP, and to achieve high selectivity. Then the synthesized MH-MIP was employed as recognition element by packing into flow cell to establish a novel flow injection CL sensor. The CL intensity responded linearly to the concentration of MH in the range 3.5 x 10(-4)-5.0 x 10(-2) mg/mL with a detection limit of 6.0 x 10(-5) mg/mL (3 sigma), which is lower than that of conventional methods. The relative standard deviation (RSD) for the determination of 1.0 mu g/mL of MH was 2.7% (n = 11). The sensor is reusable and has a great improvement in sensitivity and selectivity for CL analysis. As a result, the new MIP-CL sensor had been successfully applied to the determination of MH in vegetable samples. (C) 2008 Elsevier B.V. All rights reserved.