Abstract: In this paper, it was found that the compositing films made from polyluminol and some metal ions(such as Ni²⁺, Fe²⁺ and Co²⁺ ) can be easily generated on the surface of the graphite electrode by electropolymerization of luminol and these metal ions in the acidic medium. Compared to other resulting films, the compositing films made from polyluminol and Ni²⁺ presented the better electrochemiluminescence(ECL) analytical performance for urea based on its sensing effect for weak ECL signal of electro-oxidation polyluminol. On the basis of these results, a novel ECL method for the determination of urea in urine samples was developed, and a new method to improve the ECL analytical performances of polyluminol by compositing metal ions was also proposed. Under the optimum experimental conditions, the ECL response was linearly to the concentration of urea within the range of 2.0×10^-9—1.0×10^-7 g/mL with a detecting limit of 1.7×10^-10 g/mL.

Key words: Polyluminol film, Electrochemiluminescence(ECL), Determination of urea, Nickel ion, Electropolymerization