Electrochemical Sensor Based on a Nanocomposite of Carbon Dots, Hexadecyltrimethylammonium Bromide and Chitosan for Mesalazine Determination

A glassy carbon electrode modified with a nanocomposite consisting of carbon dots, hexadecyltrimethyl ammonium bromide and chitosan showed excellent electrocatalytic activity toward oxidation of mesalazine (MSA). Under optimal experimental conditions, hydrodynamic amperometry was used for sensitive determination of MSA. Calibration curve was obtained in the range of 0.1-10 mu M with a detection limit of 0.05 mu M. The repeatability of the method was studied for 5 replicate measurements of MSA (50 mu M) and the calculated relative standard deviation (RSD %) was 0.74%. The reproducibility for 5 different electrodes (expressed as RSD %) was 1.96% for MSA (50 mu M). The amperometric determination of the drug was successfully performed in spiked blood serum samples with recoveries ranging from 96 to 99%.