RESUMEN
The application of Propyl Paraben (PP) as a chemical preservative has expanded and diversified. Widespread use of products containing PP has resulted in its ubiquitous occurrence in environment and biological fluids among the general population. Several in-vivo studies have associated PP with estrogenic activity and malfunctioning of reproductive organs. In this work, we have developed a highly sensitive voltammetric sensor for PP detection based on polyaniline-zinc-oxide nano-composite modified carbon paste electrode (PANI/ZnO/MCPE). The synthesized nano-composite was characterized using spectroscopic techniques. Experimental conditions such as supporting electrolyte, their pH and scan rate were optimized to attain a well defined PP anodic peak current at 690 mV. Our experiments indicate a strong synergistic interaction between ZnO and PANI, resulting in the magnification of PP current with a declined over-potential, compared to bare CPE. We have proposed a mechanism of π-π interaction between PP and PANI/ZnO/MCPE. The electrode process was characterized to be irreversible; diffusion controlled and proceeds with an exchange of 1e- and H+. Noteworthy analytical performance over wide linear range from 100.0 to 1.0 µM, with a detection limit of 0.13 µM and anti-interference characteristics were ascertained. A significant advantage of this sensor is its inability to detect micro molar concentrations of ascorbic acid (AA) while PP is detected at micro levels in the presence of high concentrations of AA. The versatility of this sensor was demonstrated by efficaciously applying it to trace analysis of complex real samples such as pharmaceutical formulations, biological samples and lake water with good recoveries.
Asunto(s)
Compuestos de Anilina/química , Grafito/química , Nanocompuestos/química , Parabenos/análisis , Óxido de Zinc/química , Técnicas Electroquímicas , Electrodos , Estructura Molecular , Tamaño de la Partícula , Propiedades de SuperficieRESUMEN
Due to the enforcement of regulatory restrictions to prevent risk to human health from Bisphenol A (BPA), its structural analogue Bisphenol F (BPF) has been introduced into the market as an alternative. But however recent studies describe BPF as an effectual endocrine disruptor. Hence, there is an indispensible need for research concerning BPF human and environmental exposure level. In this work, we have elicited the development of an economical electrochemical sensor, to quantify and investigate in detail the electrochemical behavior of BPF using carbon paste electrode (CPE) modified with zinc oxide reduced graphene nanocomposite (ZnO/G) and cetyltrimethylammonium bromide (CTAB). The ZnO/G was synthesized using Hummers method and characterized by spectroscopic techniques. Under optimal conditions, conductive and biocompatible ZnO/G/CTAB/MCPE offered ultra sensitivity for BPF recognition by Differential Pulse Voltammetry (DPV), with a detection limit of 0.06⯵M. Lowering of activation energy for electro-oxidation of BPF and absence of peak for interfering molecule Ascorbic acid (AA) makes it an unique sensor for the detection of BPF with significant analytical advantage over other electrodes reported in literature. Versatility of the electrode was demonstrated by applying it to real time analysis of human body fluids, canned beverage and different water samples fortified with BPF. The satisfactory recoveries obtained, consequently authenticates the practicality of the proposed sensor.