Molecularly imprinted polymer of p-amino thiophenol for a 3-monochloropropane-1,2-diol impedance-based sensor

A sensor of 3-monochloropropane-1,2-diol (3-MCPD) has been developed using molecularly imprinted polymer (MIP) technique. The sensor was prepared from graphite pencil electrodes modified with gold particles and polymer of p-amino thiophenol as the membrane to form a self-assembled MIP with 3-MCPD. The signal of the sensor was obtained using electrochemical impedance spectroscopy calculated by the difference resistances before and after interaction between the sensor and 3-MCPD. A linear calibration curve was obtained in the 3MCPD concentration range 0.12-1.11 ppm. The estimated limits of detection and quantification of 0.12 ppm and 0.39 ppm, respectively, could be achieved. Good stability of the responses was shown with a relative standard deviation of 4.44% (n = 9) for signals repeatability in the same day and 4.20% in the different days, while it was 5.62% (n = 7) for reproducibility. The developed sensor also showed excellent selectivity for the interferences of 2-MCPD, glycerol, palmitic acid, vitamin A, and fl-carotene. Furthermore, an example application of the sensor for the detection of 3-MCPD in real cooking oil samples was also successfully demonstrated, indicating the developed sensor is promising for real applications of 3-MCPD detection.

Automated summary

A sensor for 3-monochloropropane-1,2-diol (3-MCPD) detection was developed using molecularly imprinted polymer (MIP) technique. The sensor, made from modified graphite pencil electrodes with gold particles and p-amino thiophenol polymer membrane, formed a self-assembled MIP with 3-MCPD. The sensor signal was obtained through electrochemical impedance spectroscopy, showing a linear calibration curve in the concentration range of 0.12-1.11 ppm. The sensor exhibited good stability, selectivity for interferences, and successfully detected 3-MCPD in real cooking oil samples.