A Voltammetric Sensor Based on a Chitosan, Graphitized Carbon Black, and Molecularly Imprinted Polyarylene Phthalide Composite for Clarithromycin Detection

A voltammetric sensor based on a glassy carbon electrode modified with a chitosan, Carboblack C graphitized carbon black, and molecularly imprinted polyarylene phthalide composite is developed for the selective detection of antibiotic clarithromycin. The polyarylene phthalide used for modification contains diphenylenethio- and diphenylene oxide fragments in a 1 : 2 ratio in the main polymer chain. Clarithromycin-imprinted polyarylene phthalide was obtained using the phase inversion method. The composition and morphology of the modifying coating were investigated by IR spectrometry and scanning electron microscopy. The electrochemical and analytical characteristics of the sensor were investigated by electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry. Optimal conditions for recording the analytical signal were selected. Using [Fe(CN)6]3−/4− as a probe, the linear range of the detected concentrations was found to be 1 × 10–7–5 × 10–4 M with a limit of detection of 5.3 × 10–8 M. Using a clarithromycin-imprinted polymer enhances the sensor sensitivity by nearly tenfold compared to the nonimprinted polymer. The proposed sensor was tested using urine, blood plasma, and various food samples (meat, milk), the recovery values were 90–96, 80, and 92%, respectively, with relative standard deviations not exceeding 10% in all cases.