Determination of catechin in green tea using a catechol oxidase biomimetic sensor

Journal of the Brazilian Chemical Society

Suellen C. Fernandes¹  Renata El-hage M. De Barros Osório¹  Ademir Dos Anjos¹  Ademir Neves¹  Gustavo Amadeu Micke¹  Iolanda C. Vieira¹ 

[1] ,Universidade Federal de Santa Catarina Departamento de Química Florianópolis SC ,Brazil

关键词: catechin;    green tea;    biomimetic sensor;    square wave voltammetry;   

DOI  :  10.1590/S0103-50532008000600024

来源: SciELO

【 摘 要 】

A catechol oxidase biomimetic sensor, based on a novel copper(II) complex, was developed for the determination of catechin in green tea and the results were compared with those obtained by capillary electrophoresis. The dinuclear copper(II) complex, [Cu2(HL)(µ-CH3COO)](ClO4), containing the ligand N,N-[bis-(2-pyridylmethyl)]-N',N'-[(2-hydroxybenzyl)(2-hydroxy-3,5-di-tert-butylbenzyl)]-1,3-propanediamine-2-ol (H3L), was synthesized and characterized by IR, ¹H NMR and elemental analysis. The best conditions for the optimization of the biomimetic sensor were established by square wave voltammetry. The best performance for this sensor was obtained in 75:15:10% (m/m/m) of the graphite powder:nujol:copper(II) complex, 0.05 mol L-1 phosphate buffer solution (pH 7.5) and frequency, pulse amplitude, scan increment at 30 Hz, 80 mV, 3.3 mV, respectively. The analytical curve was linear in the concentration range 4.95 × 10-6 to 3.27 × 10-5 mol L-1 (r = 0.9993) with a detection limit of 2.8 × 10-7 mol L-1. This biomimetic sensor demonstrated long-term stability (9 months; 800 determinations) and reproducibility with a relative standard deviation of 3.5%. The recovery of catechin from green tea samples ranged from 93.8 to 106.9% and the determination, compared with that obtained using capillary electrophoresis, was found to be acceptable at the 95% confidence level.

【 授权许可】

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