A sensitive simultaneous determination of epinephrine and tyrosine using an iron(III) doped zeolite-modified carbon paste electrode

Abstract

Um eletrodo de pasta de carbono modificado com zeólitas e dopado com ferro(III) foi usado como um sensor eletroquímico de alta sensibilidade e seletividade para a determinação simultânea de pequenas quantidades de compostos biologicamente importantes como epinefrina (Ep) e tirosina (Tyr). Os resultados da voltametria de pulso diferencial (DPV) usando este eletrodo modificado mostra duas ondas anódicas bem traçadas para a oxidação da Ep e da Tyr, as quais tornam possíveis a determinação simultanêa destes compostos. A faixa linear de 0,9 a 216 mmol L -1 para a Ep em uma concentração fixa de 30 mmol L -1 Tyr em solução tampão fosfato, pH 3,0 foi obtida das medidas de DPV usando este eletrodo, com um coeficiente de correlação de 0,9998 e limite de quantificação igual a 0,44 mmol L -1 . A linearidade obtida para a Tyr na presença de 30 mmol L -1 de Ep, foi de 1,2 a 90 mmol L -1 com um coeficiente de correlação de 0,9989 e limite de quantificação de 0,32 mmol L -1 . O eletrodo modificado apresentou uma boa reprodutibilidade (RSD< 2.5%), baixo limite de quantificação (sub-micromolar) e alta sensibilidade para a detecção de ambos Ep e Tyr com uma elevada estabilidade em sua resposta voltamétrica. O desempenho analítico deste sensor tem sido avaliado para a detecção de epinefrina e tirosina em soro humano e em amostras farmacêuticas com resultados satisfatórios.A Zeolite modified carbon paste electrode doped with iron(III) was used as a highly sensitive and selective electrochemical sensor for simultaneous determination of minor amounts of epinephrine (Ep) and tyrosine (Tyr) as the biologically important compounds. The results of differential pulse voltammetry (DPV) using this modified electrode show two well-resolved anodic waves for the oxidation of Ep and Tyr ,which makes it possible for simultaneous determination of both compounds. A linear range from 0.9 to 216 mmol L -1 for Ep at a constant concentration of 30 mmol L -1 Tyr in buffered solution (phosphate buffer, pH 3.0) was obtained from DPV measurement using this electrode with a correlation coefficient of 0.9998 and a detection limit of 0.44 mmol L -1 . The linear range, which is obtained for Tyr in the presence of 30 mmol L -1 Ep, was in the range from 1.2 to 90 µmol L -1 with a correlation coefficient of 0.9989 and a detection limit of 0.32 mmol L -1 . The modified electrode had good reproducibility (RSD < 2.5%), low detection limit (sub-micromolar) and high sensitivity for the detection of both Ep and Tyr with a very high stability in its voltammetric response. The analytical performance of this sensor has been evaluated for detection of Ep and Tyr in human serum and in a pharmaceutical sample with satisfactory results.Keywords: Epinephrine, tyrosine, Fe(III) doped zeolite, modified carbon paste electrode IntroductionEpinephrine (Ep), Scheme 1 (a), often called adrenaline, is one of the most important neurotransmitters in mammalian central nervous systems, existing in the nervous tissue and body fluid, and controlling the nervous system in the performance of ...

Electrocatalytic oxidation of l-tyrosine at carboxylic acid functionalized multi-walled carbon nanotubes modified carbon paste electrode

“…A biosensor based on hemin immobilized reduced graphene oxide nanosheets on glassy carbon electrode, iron (III) doped zeolite modified carbon paste electrode, amperometric sensor based on tetroxide nanoparticles-graphene nanocomposite film modified glassy carbon electrode, chiral electrochemical sensor modified with cysteic acid and gold nanoparticles decorated graphene oxide glassy carbon electrode [23][24][25][26][27] are employed for the sensitive determination of Tyr. There is a report on the analysis of Tyr using SWCNTs modified glassy carbon electrode (GCE) [28], though the GCE requires pretreatment and Tyr suffers from oxidation overpotential at SWCNTs/GCE apart from it not being applied for real sample analysis directly.…”

Mechanistic aspects of tyrosine sensing on an in situ copper oxide modified molecularly imprinted polypyrrole coated glassy carbon electrode

“…The adsorption mechanism is further supported by the observation that cathodic reduction peaks are combination of copper oxide and copper phosphate reported by Somasundrum and co-workers [24]. The fact that tyrosine analytical signal is maximum at a pH of 5.5 rules out ion exchange mechanism (which is expected to give maximum analytical signal at pH 3) invoked by Babaei et al [7] in case of zeolite modified carbon paste electrode.…”

“…Balla et al [6] reported electrocatalytic oxidation of catechol in presence of copper ions. Babaei and coworkers [7] proposed an ion exchange mechanism in case of Zeolite modified carbon paste electrode for the simultaneous determination of epinephrine (Ep) and tyrosine (Tyr). Several researchers have reported plausible pathways like proton electron transfer processes for electrochemical oxidation of tyrosine using MWCNT and gold nanoparticle modified GCE respectively [8,9].…”

Voltammetric Determination of Epinephrine in Pharmaceutical Sample with a Tyrosinase Nanobiosensor

“…According to Table 1, the developed biosensor shows wider linear range than some of them [3, 4, 21, 27, 30, 32-35, 48, 49, 51]. The detection limit of the developed biosensor is also better than some electrodes [27,30,32,33,35,48,49,51,6 Journal of Sensors [52], and 2.9 × 10 −8 M for CPE/MWCNTs [28]. In the present study, obtained estimation limit value is comparable with the findings reported in the relevant literature.…”