Ultrasensitive Detection of Ferulic Acid Using Poly(diallyldimethylammonium chloride) Functionalized Graphene-Based Electrochemical Sensor

Abstract

The electrochemical redox of ferulic acid (FA) was investigated systematically by cyclic voltammetry (CV) with a poly(diallyldimethylammonium chloride) functionalized graphene-modified glassy carbon electrode (PDDA-G/GCE) as a working electrode. A simple and sensitive differential pulse voltammetry (DPV) technique was proposed for the direct quantitative determination of FA inAngelica sinensisand spiked human urine samples for the first time. The dependence of the intensities of currents and potentials on nature of the supporting electrolyte, pH, scan rate, and concentration was investigated. Under optimal conditions, the proposed sensor exhibited excellent electrochemical sensitivity to FA, and the oxidation peak current was proportional to FA concentration in the range of8.95×10-8 M~5.29×10-5 M, with a relatively low detection limit of4.42×10-8 M. This fabricated sensor also displayed acceptable reproducibility, long-term stability, and high selectivity with negligible interferences from common interfering species. Besides, it was applied to detect FA inAngelica sinensisand biological samples with satisfactory results, making it a potential alternative tool for the quantitative detection of FA in pharmaceutical analysis.