A Highly Selective Sensor for 5-Aminosalicylic acid using carbon paste electrode modified by MWCNT/ molecular imprinted polymer

In this work, electrooxidation behavior of drug 5-Aminosalicylic acid using multi wall carbon nanotube/ Poly methacrylic molecular imprinted polymer modified carbon past electrode (MWCNT/MIP-CPE) was investigated. The electrochemical behavior of the MWCNT/MIP-CPE for detection of 5-Aminosalicylic acid was investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The surface feature of the modified electrode MWCNT/MIP-CPE was characterized by scanning electron microscopy (SEM). The MIP and non-imprinted polymers (NIP) were synthesized using 5-ASA as a template, methacrylic acid (MAA) as a monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linker and 2-Azobisisobutyronitrile (AIBN) as an initiator. All effective factors in this experiment and the interactions between them were optimized in six factors and five levels by Design Expert software Version 7. Based on the software, minimum number of required runs was 33. In these runs, polymers were synthesized quite carefully. All carbon paste electrodes were modified by synthesized polymers and electrochemical measurements were performed in scan rate and pH levels that optimized by the software and responses were examined by ANOVA Analysis Method. A dynamic linear range of 10-500μM was obtained. The detection limit of the sensor was calculated as 4.6μM. As other imprinted materials, one of the main functions of the proposed MWCNT/MIP-CPE was to improve the selectivity of electrochemical sensors. Thus, this sensor was used successfully for the 5-Aminosalicylic acid determination in a commercial pharmaceutical formulation and human serum.