Title : Molecularly imprinted polymer-bimetallic nanoparticle based electrochemical sensor for dual detection of phenol iosmers micopollutants in water
Abstract:
Fast and selective electrochemical sensors for the dual detection of emerging environmental phenolic microcontaminants namely catechol (CC) and hydroquinone (HQ) in water is reported in this work. The sensor was fabricated through the modification glassy carbon electrode (GCE) with silver-nickel nanoparticles (Ag-NiNP/GCE) and molecularly imprinted poly(p-phenylenediamine) (MIP-p-PD-Ag-Ni/GCE) in the presence of CC and HQ as templates using electrodeposition technique sequentially. The elution of CC and HQ generated the specific binding sites to recognize and detect the templates with strong affinity. The electrodes and the materials were characterized using cyclic voltammetry, square wave voltammetry (SWV), Fourier infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. Experimental conditions such as number electropolymerization cycles, ratio of template-to-functional monomer, pH of electrolytes, and time of templates elution were carefully optimized. The SWV measurements showed that the sensor can detect the mixture of CC and HQ in phosphate buffer solution (pH 7) in the linear range of 0.75 -200 µM and 0-200 µM, with limit of detection (LOD) of 0.054 and 0.045 µM, respectively. The incorporation of Ag-NiNP in to MIPs improved the electrocatalysis of the targets through increasing the surface-area-to-volume ratio and conductivity of the electrode while the MIP played the role of selective recognition of CC and HQ analytes. The MIP-p-PD-AgNiNP/GCE sensor exhibited an acceptable percentage recovery of 96.45-102.56% with RSD of 2.62-3.54% for the water samples spiked with known quantities of CC and HQ. Furthermore, the proposed sensor revealed its high stability, selectivity and reusability which evidence its future applications in environmental monitoring applications.
