Developing of molecularly imprinted electrochemical sensor for selective paraben detection

Parabens; they are known as endocrine disruptors (EDCs), which modify the development and functioning of the endocrine system by acting as hormons or blocking their function when they are taken in the body. They are para-hydroxybenzoic acid derivatives including methylparaben, ethylparaben, butylparaben and propylparaben. In this work, polymer surfaces with para-hydroxybenzoic acid (paraben) selective are designed using molecular imprinted technique. A new, simple, fast, sensitive and selective analysis method has been developed for the detection of parabens by voltammetric methods via using molecular imprinted technique. The precursor complex of the paraben with the functional monomer synthesized from the amino acid L-phenylalanine N-methyl-L-phenylalanine (MAPA) was prepared. The pre-complex structure of the obtained paraben with MAPA was polymerized on a gold surface in the presence of polyvinyl alcohol (PVA) (for the purpose of an adjustable porous structure) with 2-hydroxyethyl methacrylate. By synthesizing amino acid-based polymerizable functional monomers, synthetic polymers [poly(2-hydroxyethylmethacrylate)] (pHEMA) have been transferred to highly selective binding properties of many biomolecules such as proteins and enzymes. Screen-printed gold electrode was used as a working electrode. The electrodes were characterized with cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). For the electrochemical behavior of the paraben, the cyclic voltammetry (CV) and square wave voltammetry (SWV) methods were used. Under optimized conditions, working linear range was found as from 1 to 30 µM. The limit of detection (LOD) and limit of quantification (LOQ) were obtained as 0,706 µM and 2.35 µM, respectively. The selectivity of the surface was investigated and imprinted paraben showed high selectivity aganist paraben. The developed method has been successfully applied in cosmetic samples.