Developing a highly sensitive electrochemical sensor using thiourea-imprinted polymers based on an MWCNT modified carbon ceramic electrode

In the present study, a new electrochemical sensor based on Molecularly Imprinted Polymer (MIP) was designed for detection and determination of Thiourea (TU) in industrial and biological media. The effect of different parameters, such as solution pH and duration of TU pre-concentration, on the electrode surface was investigated along with optimization of MIP and MWCNT quantities for fabrication of the electrode. The study was conducted using the statistical respond surface methodology. The optimized conditions were determined as MWCNT = 3.3 mg and MIP = 12.3 mg for fabrication of the sensor. Also, a pH of 8.0 and a time duration of 26.0 min were found for pre-concentration of TU on the prepared sensor. The results showed that the developed sensor (TUMIP/MWCNT/CCE) has a higher sensitivity than bare carbon ceramic electrode (CCE), MWCNT/CCE, and TUMIP/CCE. The sensor showed two linear response ranges of 0.05-5.0 nM and 5.0-1100.0 nM and a detection limit of 8.0 pM versus TU. Finally, the sensor was satisfactorily used to determine TU in the copper refinery electrolyte of Sar-cheshmeh copper Co., and in such real samples as tap water and orange juice.