Development of a molecularly imprinted electrochemical sensor for determination of sulfasalazine used in rheumatoid arthritis treatment

In this thesis, over oxidized molecularly imprinted polymer (MIP) and non-imprinted polymer (NIP) modified pencil graphite electrodes (PGE) were used in the electrochemical determination of the sulfasalazine (SSZ) molecule. The electrodes were attained by electropolymerization of pyrrole onto a pencil graphite electrode by cyclic voltammetry (CV) method. Optimum conditions have been determined for parameters that may affect the response of electrodes such as potential range, number of cycles, scan rate, concentration of analyte, medium and pH. As a result of the measurements, the optimum potential range was determined as (-0.6)-(+0.9) V, the number of cycles as 6, the scanning speed as 100 mV/s and the concentration of analyte as 200 ppm. The performance of electrodes on SSZ determination was investigated by differential pulse voltammetry (DPV) method. Electrochemical analyzes were performed in Britton-Robinson buffer solution with pH 5 in ACN-water binary mixture containing 10% (v/v) acetonitrile (ACN). The linear working range was determined as 1-10 ppm (r = 0.999) and the detection limit was calculated as 0.265 ppm. Pharmaceutical sample studies were carried out with the developed MIP electrode. The calculated 101.2% and 103.0% recovery values showed the accuracy of the developed method. As a result, it has been observed that molecularly imprinted electrodes are more selective and sensitive to sulfasalazine than non-imprinted electrodes.