Abstract
Gliclazide sensing was investigated based on differential pulse voltammetry measurements of an electropolymerized molecularly imprinted polymer (E-MIP) film. The E-MIP polymer was prepared via anodic electropolymerization of pyrrole in the presence of GLZ onto glassy carbon electrodes using cyclic voltammetry (CV). GLZ molecules are successfully trapped into the polypyrrole matrix creating, after their subsequent removal, shape-complementary artificial recognition sites. The effect of several significant operational parameters (monomer and template concentrations, number of CV scans, pH and incubation time) on film analytical performances were investigated and optimized. Under optimized conditions, the sensor response exhibited high sensitivity toward the target template and was linearly proportional to GLZ concentration (R-2 = 0.998) over the range 5 x 10(-11)4 x 10(-10) M, with a detection limit (3 sigma/m) of 1.2 x 10(-11) M. The precision of the method (R.S.D., n = 6) for within and between-days is better than 1.4% and 2.48%, respectively at 10(-10) M. Moreover, the selectivity of E-MIP sensor, against potentially competing molecules (Imp. B, Imp. E, glipizide, glibenclamide, glimepiride), was demonstrated. The developed E-MIP sensor was successfully applied to the determination of GLZ in three pharmaceutical products and gave results in close agreement with the reference HPLC method with mean recoveries between 95.4 and 98.8%, showing promising potential in practical applications. (C) 2014 Elsevier B.V. All rights reserved.