The role of porogen-polymer complexation in atrazine imprinted polymer to work as an electrochemical sensor in water

Abstract An electrochemical sensor was successfully assembled by adopting the optimum molecularly imprinted polymers together with an electrochemical system. The sensor utilizes the molecular imprinted polymer (MIP) synthesized for atrazine detection in aqueous solutions. The effect of three different co-porogen in the polymer formulation were evaluated for atrazine binding capacity, imprinting factor and by using scanning electron microscopy (SEM). The imprinting factor for the polymer was the highest for the smallest difference of the polymer solubility parameter with the porogen mixture. Among all polymers, the polymer with 10% of DMSO gives the highest imprinting factor of 1.18 and binding capacity of 0.016 mmol.g−1 of polymer. The optimum formulation of imprinted polymer was assembled with graphite felt electrode as the transduction for electrochemical analysis. Electrochemical impedance spectrum (EIS) was used to characterize the sensor and investigate the electrochemical response of the sensor. An equivalent circuit was suggested to quantitatively analyze each component of the sensor system. All EIS curves fit well with three different circuits corresponding to the presence or absent of PVC and polymers in the blend, as well as the presence of the atrazine in the electrolyte solution with the accuracy of the fits χ2 value between 0.6298 and 1.475. The variation of individual values of parameters deduced from the impedance fits were scrutinized.