A Rapid Modified Glassy Carbon Electrode With Reduced Graphene Oxide-Polyanilne-Gold Nanoparticals Composite To Detect Bisphenol A

Bisphenol A?BPA?is a potential endocrine disruptor compound?EDC?that causes many harmful effects on human health and the environment.As a consequence,the rapid,accurate,precise,and efficient method to determinate the level of BPA is an urgent requirement to protect our health and ecosystem.In this research,reduced graphene oxide?rGO?,polyaniline?PANI?,gold nanoparticles?AuNPs?are the three main components to modify a native glassy carbon electrode?GCE?,assisted with chitosan solution?CHI?which acts as the film protection and linker for determination of BPA level.Due to the unique characteristics such as good conductivity and the high electroactive surface ratio of rGO,PANI and AuNPs,The oxidation of BPA on the modified electrode was improved as can see from increasing of I_paa current.For modification procedure,the drop coating method was used to fabrication the rGO-PANI/AuNPs/CHI/GCE because of its strong points;easy performance,highly reproducible procedure,simpler preparation.At the modification process,the optimal volume,concentration,amount including the sequence of depositing and pretreatment process were studied.From the study,the optimal formula to modify GCE is 10?L of rGO-PANI after dilution with deionized water 2 times+10?L of AuNPs+5?L of 0.05%chitosan solution on bare GCE.The total layers are three layers.The characterization of the modified electrode and electrochemical behaviors were also investigated.The results from SEM images disclosed the modified electrode was fabricated successfully via the method mentioned above and the CV and EIS results demonstrated that the rGO-PANI/AuNPs could capably boost the electrochemical performance in the oxidation reaction of BPA.In electrochemical detection of BPA,experimental parameters such as the pH values,the concentration of phosphate buffer?PBS?and accumulation time were optimized and tested,as well as the influence of pH and scan rate.As results,the pH values,the concentration of PBS,and accumulation time were set to 8.5,0.07 mol/L and300s,respectively.Additionally,the results from studying the influence of pH values and scan rate indicated that the proposed modified electrode was a diffusion-controlled process consisting of four electrons and four protons transfer.For practical application,the validation method was used to verify the usage competence of the developed electrode.According to the results of differential pulse voltammetry?DPV?under optimal experimental conditions,the proposed modified electrode exhibited the excellent performance for BPA quantification with three linear ranges from 1-5?mol/L,5-60?mol/L and 60-180?mol/L with 0.1767?mol/L of the detection limit?S/N=7?.Aside from what has been discussed,the modified GCE has still possessed a high sensitivity,long-term stability,impressive reproducibility and good performance in real sample analysis within the accord of comparative spectroscopic technique and%Recovery.This study indicated that rGO-PANI/AuNPs/CHI/GCE could be a promising and reliable tool for BPA determination and further potential applications for detecting other endocrine disruptors with similar chemical structures.