Abstract: Using L-tryptophan (L-Trp) as template molecule and o-phenylenediamine as functional monomer, the sensitive molecularly imprinted polymer films was prepared on the surface of a gold electrode by in-situ polymerization. The performance of the imprinted electrode was characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electro-chemical impedance spectroscopy (EIS). A linear relationship between oxidation peak current and concentration of L-Trp was obtained over a range from 1 x 10-8 to 2 x 10-7 mol L-1 with a detection limit of 0.3 x 10-8 mol L-1. From the selectivity experiments,the imprinting factor of L-Trp imprinted film was 3.72 and the selectivity factors compared to interferents were all larger than 1. Although a minor interference was generated by L-Tyr for its structure similar to L-Trp, the selectivity factor also reached 2.30. This indicated that the imprinted polymer films had a good selectivity for L-Trp. The kinetics of recognition revealed a two-step process of the imprinted polymer films adsorbing L-Trp, a fast binding process and a slow adsorption process.
Template and target information: L-tryptophan, L-Trp
Author keywords: L-tryptophan, molecular imprinting, electrochemical polymerization, sensitive film, Recognition process

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