Construction of β-Cyclodextrin-phosphomolybdate grafted polypyrrole composite: application as a disposable electrochemical sensor for detection of Propylparaben

Abstract Herein, a newly introduced electrochemical sensor based on polypyrrole (PPy) grafted by the organic–inorganic β-Cyclodextrin (β-CD)-phosphomolybdate (PMo12) composite is reported for detection of propylparaben (PP). The host–guest chemistry was utilized to synthesize the macromolecular self-assembly of β-CD-PMo12 that was subsequently verified by nuclear magnetic resonance (NMR) spectroscopy and used as a kind of dopant for electropolymerization of pyrrole (Py) on a pencil graphite electrode (PGE). The morphology and the physical properties of the electrodeposited film were characterized using field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV). Overoxidation of the electropolymerized film was necessary for conditioning the modified electrode to detect PP. Following the optimization of the important influential parameters on the sensor response towards PP, differential pulse voltammetry (DPV) was used to construct the concentration calibration curve. The designed sensor demonstrated two linear responses within the ranges of 0.2 µM to 10 µM and 10 µM to 100 µM with limits of detection (LOD) and quantification (LOQ) of 0.04 μM and 0.1 μM based on 3sb/m and 10sb/m criteria, respectively. The real analytical applicability of the proposed sensor was examined through the determination of PP in a commercial cleansing micellar solution, which showed acceptable recoveries and favorable performance.