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Determination of gallic acid using poly(glutamic acid): graphene modified electrode

2019; Springer Science+Business Media; Volume: 131; Issue: 2 Linguagem: Inglês

10.1007/s12039-018-1587-0

0974-3626

J. Jency Feminus, R. Manikandan, S. Sriman Narayanan, P. N. Deepa,

Conducting polymers and applications

Gallic acid (GA) is one of the main phenolic components occurring naturally in plants and has been a subject of increasing interest owing to its antioxidant, anti-mutagenic and anti-carcinogenic properties. The present work describes a rapid and cost-effective analytical procedure for the determination of gallic acid. Poly-Glu/rGO electrode was fabricated by the electro-polymerisation of glutamic acid on reduced graphene oxide (rGO) modified paraffin impregnated graphite electrode (PIGE). The modified electrode was characterized by SEM, AFM and ATR-IR. The electrochemical behavior of gallic acid at the modified sensor was studied by voltammetric and amperometric techniques under optimized conditions in pH 5 acetate buffer. The electrode showed good linear response towards the determination of gallic acid over the range of 0.03–480 $$\upmu {\hbox {M}}$$ with 0.01 $$\upmu \hbox {M}$$ as the detection limit for voltammetric technique and the amperometric technique showed a linear range of 1–17 $$\upmu \hbox {M}$$ with 0.33 $$\upmu \hbox {M}$$ as the detection limit. The electrode also showed good stability and reproducibility with a sensitivity of 0.97 $$\upmu \hbox {M}$$ / $$\upmu $$ A. The proposed method can be applied to detect GA in real samples with satisfactory results. SYNOPSIS This work describes a rapid and cost-effective analytical procedure for the determination of gallic acid. Poly-Glu/rGO electrode was fabricated by electro-polymerisation of glutamic acid on reduced graphene oxide (rGO) modified paraffin impregnated graphite electrode (PIGE). The electrode showed linear response towards gallic acid over the range of 0.03–480 $$\upmu \hbox {M}$$ with 0.01 $$\upmu \hbox {M}$$ as the detection limit for voltammetric technique and a linear range of 1–17 $$\upmu \hbox {M}$$ with 0.33 $$\upmu \hbox {M}$$ as the detection limit for amperometric technique. The proposed electrochemical sensor can be applied to detect GA in real samples with satisfactory results.