A highly sensitive plastic optic-fiber with a molecularly imprinted polymer coating for selective detection of 4-chlorophenol in water

Abstract

To realize the selective detection of 4-chlorophenol (4-CP) in water, a highly sensitive plastic optical fiber (POF) evanescent wave sensor was prepared using a D-shaped POF coated selective adsorption film of 4-CP. The film was composed of molecularly imprinted polymer (MIP) particles and PEBA2533 matrix. The MIP particles were employed to realize the selective adsorption and enrichment of 4-CP molecules, which lead to the changes in the refractive index of the MIP-PEBA2533 coating. These, in turn, resulted in changes in the light transmission in the D-shaped region and caused the attenuation of the evanescent field intensity on the surface of the sensing region. To illustrate the measurement principle, a theoretical model of the sensor was established. Furthermore, the performance parameters of the sensors, such as sensitivity, repeatability, selectivity and low limit of detection (LOD), were experimentally studied. The results highlighted that the proposed sensor exhibited a good sensitivity of -0.56 × 10-6 (μg/L)-1 and LOD of 100 μg/L for the detection of 4-CP in water. Moreover, this optic-fiber sensor has high specific recognition ability for 4-CP. The results of this study could inform the development of methods for on-line and accurate detection of 4-CP.