Carbon Composite Electrode Modified with Copper(II) Phosphate Immobilized in a Polyester Resin for Voltammetric Determination of Catechin in Teas

Freitas, Kellen Heloizy Garcia; Fatibello‐Filho, Orlando

doi:10.1080/00032711003687112

Cited by 8 publications

(3 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…An example might be the modification by ionic liquid such as n ‐octylpyridinehexafluorophosphate, which increases the rate of electron transfer during the oxidation of ascorbic acid 17. Another example of modification of carbon composite electrode is voltammetric determination of catechine in samples of teas, where the copper phosphate is added to increase the signal 19. Many other compounds can be used as modifiers for achieving desired properties, e.g., enzymes 15, 20, synthetic polymers 21, organometallic compounds 22, or polysaccharides 23.…”

Section: Introductionmentioning

confidence: 99%

Defect‐Rich CoP/Nitrogen‐Doped Carbon Composites Derived from a Metal–Organic Framework: High‐Performance Electrocatalysts for the Hydrogen Evolution Reaction

et al. 2015

View full text Add to dashboard Cite

A defect‐rich CoP/nitrogen‐doped carbon composite is reported for the first time derived from ZIF‐67 by means of low‐temperature phosphidation process. As a hydrogen evolution reaction electrocatalyst, the obtained CoP‐N‐C has high HER activity and good stability with a low onset overpotential of 31 mV, a small Tafel slope of 42 mV dec−1, a large exchange current density of 1.6×10−1 mA cm−2, and a 10 mA cm−2 current density at overpotential 91 mV.

show abstract

Section: Introductionmentioning

confidence: 99%

Defect‐Rich CoP/Nitrogen‐Doped Carbon Composites Derived from a Metal–Organic Framework: High‐Performance Electrocatalysts for the Hydrogen Evolution Reaction

et al. 2015

View full text Add to dashboard Cite

show abstract

“…A tabela 1 mostra os dados obtidos neste trabalho em comparação a outros dados da literatura com estudos de determinação de CTQ. [38] * este trabalho Analisando a tabela, é possível observar que o eletrodo objeto de estudo deste trabalho é suficientemente aplicável para a detecção de CTQ, uma vez que apresenta LD e LQ dentro da ordem de grandeza de técnicas eletroanalíticas mais sensíveis comparadas com este trabalho.…”

Section: Curva Analíticaunclassified

Determinação de catequinas por eletrodo de carbono impresso modificado com nanotubo de carbono funcionalizado

Silva

Kubota

et al. 2016

Eclet. Quim.

View full text Add to dashboard Cite

____________________________________________________________________________Resumo: A Catequina é um composto fenólico com grande potencial oxidante, encontrada em diversos tipos de alimentos, dentre alguns dos benefícios da catequina estão o fortalecimento capilar, melhoria do fluxo sanguíneo, redução dos níveis de colesterol. Neste artigo, utilizou-se da técnica de voltametria cíclica (VC) para otimizar o eletrodo de carbono impresso modificado com nanotubo de carbono funcionalizado para detectar e quantificar catequina por meio da técnica de voltametria de onda quadrada (VOQ). Para este eletrodo, os melhores resultados foram obtidos a uma concentração de 1x10 -3 mol L -1 de catequina em meio de tampão fosfato 0,1 mol L -1 pH 7,0 a uma velocidade de varredura de potencial de 0,05 V s -1 . A partir destas condições foi obtida uma curva analítica com comportamento linear no intervalo de concentração de catequina entre 2,0x10 -7 a 1,68x10, com limites de detecção e de quantificação de 9,2x10 -8 e 3,0x10 -7 mol L -1, respectivamente por VOQ. Este eletrodo apresentou boa repetibilidade com um desvio de padrão relativo de 4,05%. A oxidação da catequina apresentou um pico localizado em torno de 0,15V vs Ag/AgCl, estando próximo dos potenciais de pico mostrados na literatura.Palavras-chave: catequina, eletrodo de carbono impresso, nanotubo de carbono, sensor eletroquímico ____________________________________________________________________________ Abstract: Catechin is a phenolic compound with high oxidizing potential, found in several types of foods, some of the benefits of catechins are capillary strengthening, improvement of blood flow and reduction of cholesterol levels. In this paper, it was used the cyclic voltammetry technique (CV) to optimize the printed carbon electrode modified with carbon nanotube, functionalized to detect and quantify catechin by means of the squarewave voltammetry technique (SWV). For this electrode, the best results were obtained at a catechin concentration of 1x10 -3 mol L -1 in means of 0.1 mol L -1 phosphate buffer pH 7.0 at a potential scan rate of 0.05 V s -1 . From these conditions, an analytical curve was obtained with a linear behavior in the catechin concentration range of 1,68x10 -5 to 2,0x10 -7 mol L -1, with limits of detection and quantification of 9,2x10 -8 and 3,0x10 -7 mol L -1 , respectively, by SWV. This electrode showed good repeatability with a standard deviation of 4.05%. Oxidation of catechin showed a peak located around 0,15V vs Ag / AgCl, being close to the peak potentials shown in the literature.

show abstract

“…Moreover, the Cu 3 (PO 4 ) 2 electrodes oxidized at +0.11 V for 120 s in 20 mM Na 2 HPO 4 solution (pH 5.0), named ox-Cu 3 (PO 4 ) 2 , can promote the AA oxidation. 9 Nevertheless, the ox-Cu 3 (PO 4 ) 2 electrodes are only suitable for use in acidic phosphate solutions (pH 5-6) because of the formation of insulating Cu(OH) 2 and the dissolution of the Cu 3 (PO 4 ) 2 layer in alkaline solutions, 9,14,15 thus limiting practical applications to physiological environments of about pH 7.4. Therefore, it would be useful to extend the application of ox-Cu 3 (PO 4 ) 2 electrodes in pH-varied solutions (pH > 6).…”

mentioning

confidence: 99%

Ionic Liquid-Modified Copper Phosphate Electrodes for the Detection of α-Amino Acids in a Weakly Alkaline Solution

Lee

Chang²,

et al. 2016

J. Electrochem. Soc.

View full text Add to dashboard Cite

The effect of ionic liquid (IL) coating on the electrochemical properties of preoxidized Cu 3 (PO 4 ) 2 (ox-Cu 3 (PO 4 ) 2 ) electrodes was explored in pH-varied Na 2 HPO 4 solutions. The IL of N-propyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PMPy-TFSI) was found to stabilize the redox properties of ox-Cu 3 (PO 4 ) 2 electrodes in weakly acid and alkaline solutions. Furthermore, the amperometric response of the PMPy-TFSI/ox-Cu 3 (PO 4 ) 2 electrodes presented good linearity in the range of 91-500 μM for most α-amino acids (AAs). The PMPy-TFSI/ox-Cu 3 (PO 4 ) 2 electrodes are equipped with a high performance liquid chromatography system to perform the good selectively and specific detection of AAs. The PMPy-TFSI coating shows promise for the wider application of ox-Cu 3 (PO 4 ) 2 electrodes in acidic and alkaline solutions for the detection of electroactive and nonelectroacitve AAs.

show abstract

Carbon Composite Electrode Modified with Copper(II) Phosphate Immobilized in a Polyester Resin for Voltammetric Determination of Catechin in Teas

Cited by 8 publications

References 36 publications

Defect‐Rich CoP/Nitrogen‐Doped Carbon Composites Derived from a Metal–Organic Framework: High‐Performance Electrocatalysts for the Hydrogen Evolution Reaction

Defect‐Rich CoP/Nitrogen‐Doped Carbon Composites Derived from a Metal–Organic Framework: High‐Performance Electrocatalysts for the Hydrogen Evolution Reaction

Determinação de catequinas por eletrodo de carbono impresso modificado com nanotubo de carbono funcionalizado

Ionic Liquid-Modified Copper Phosphate Electrodes for the Detection of α-Amino Acids in a Weakly Alkaline Solution

Contact Info

Product

Resources

About