An electrochemical sensor for gallic acid based on Fe₂O₃/electro-reduced graphene oxide composite: Estimation for the antioxidant capacity index of wines.
A highly sensitive electrochemical sensor for gallic acid (GA), an important polyphenolic compound, was fabricated using the hybrid material of chitosan (CS), fishbone-shaped Fe2O3 (fFe2O3), and electrochemically reduced graphene oxide (ERGO) as the sensing matrix. The electrochemical characterization experiments showed that the CS-fFe2O3-ERGO modified glassy carbon electrode (CS-fFe2O3-ERGO/GCE) had large surface area, excellent electronic conductivity and high stability. The GA presented a superior electrochemical response on CS-fFe2O3-ERGO/GCE in comparison with the single-component modified electrode. The electrochemical mechanism and optimal test conditions of GA on the electrode surface were carefully investigated. Under the optimal conditions, the oxidation peak currents in differential pulse voltammetry (DPV) experiments exhibited a good linear relationship with the logarithmic values of GA concentration over the range from 1.0×10(-6)M to 1.0×10(-4)M. Based on signal-to-noise (S/N) characteristic of 3, the detection limit was estimated to be 1.5×10(-7)M. The proposed sensor has also been applied for estimating the antioxidant capacity index of real samples of red and white wines.
College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, PR China; Department of Chemistry, Graduate School of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan. Electronic address: fgao1981@126.com.
Feng
F
Gao
College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, PR China.
Delun
D
Zheng
Department of Chemistry, Graduate School of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504, Japan.
Hidekazu
H
Tanaka
College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, PR China.
Fengping
F
Zhan
College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, PR China.
Xiaoning
X
Yuan
College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, PR China.
Fei
F
Gao
College of Chemistry and Environment, Fujian Province Key Laboratory of Morden Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, PR China. Electronic address: axiang236@126.com.
Qingxiang
Q
Wang
D000975:Antioxidants / Q000032:analysis*; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004595:Electroplating; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005290:Ferric Compounds / Q000737:chemistry*; D005504:Food Analysis / Q000295:instrumentation*; D005707:Gallic Acid / Q000032:analysis*; D006108:Graphite / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D010084:Oxidation-Reduction; D014920:Wine / Q000032:analysis*
D000975:Antioxidants; D005290:Ferric Compounds; C000499:ferric oxide; D005707:Gallic Acid; D006108:Graphite
Electro-reduced graphene oxide; Electrochemical sensor; Gallic acid; Iron oxide