Application of electrochemical sensor modified by SBA-15 /Fe3O4/polyaniline nanocomposite for determination of tyrosine in milk samples

Abstract

In this study, a selective SBA-15 /Fe3O4/Polyaniline /Chitosan nanocomposite was successfully electrodeposited on Screen- Printed Carbon Electrode (SPCE) and used for L-Tyrosine (Tyr) detection.Biological diagnostic probes such as artificial receptors are one of the important diagnostic layers for the identification of vital biomolecules, including essential amino acids like Tyr. A new electrochemical sensing platform based on differential pulse voltammetry was prepared for selective determination of Tyr in milk samples.SBA-15 nanoparticles were synthesized from corn leaves as a source of silica. These high-absorbance nanoparticles have been used for surface modification of SPCE. The morphology and electrochemical performance of the modified electrode were characterized by X-ray diffraction, scanning electron microscopy (SEM), transition electron microscopy (TEM), Furrier transform infrared spectroscopy (FTIR), Brunauer-Emmett–Teller techniques, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry(CV).As a novel modified electrode, the catalytic activity of the modified SPCE towards electro-oxidation of Tyr was measured by differential pulse voltammetry (DPV). The experimental conditions, including the adsorption time, scan rates, the ratio of SBA-15, pH value, and applied potential, are investigated in detail.Electrochemical sensor based on SBA-15 (SPCE/SBA-15/Fe3O4/Polyaniline /Chitosan) Compared with SPCE/Fe3O4/Polyaniline/Chitosan shows good sensitivity, repeatability, reproducibility, low detection limit and high selectivity.In addition, a linear correlation between oxidation peak current and concentration of Tyr in the ranges 0.1–250 μM with a detection limit of 0.05 μM (S/N = 3) was obtained. Eventually, the suggested sensor was used for quantification of Tyr in real samples, by adding standard solutions to the milk samples.