Construction of a Highly Selective and Sensitive Dopamine Enzyme‐free Biosensor Based on Carbon Nanomaterials

Liu, Chong; Xie, Yuchen; Hou, Yingjiao; Wang, Ziyi; Pan, Xiaoyu; Zhu, Hong; Li, Hongna

doi:10.1002/elan.202100094

Cited by 4 publications

(3 citation statements)

References 16 publications

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“…Due to the synergistic effect of the association of GNPs with CNTs [ 76 ], interaction with catechin is favored, with improved selectivity and sensitivity of the CNT-GNP-Lac/SPE biosensor, which shows better performances than the other two biosensors.…”

Section: Resultsmentioning

confidence: 99%

“…Even when a fixed-time ABTS assay is preferred, the results may greatly vary for the same compound depending on the oxidizing agent used to generate the stable colored radical [106]. The ABTS +• cation radical was prepared according to the method presented by Kurin et al [76], with some adjustments. Equal volumes of 5 mM ABTS solution and 2.45 mM K2S2O8 solution were mixed, and the resulting mixture was kept at room temperature and in the dark for 24 h. After this time, the ABTS +• cation radical solution was diluted with ethanol until the absorbance value at 734 nm was close to 1 [77].…”

Section: Abts Methodsmentioning

confidence: 99%

“…Taking into account the values mentioned in this table, we can say that the low values of the detection and quantification limits are in agreement with the values obtained by other types of sensors or biosensors able to determine catechin in real-life samples. Due to the synergistic effect of the association of GNPs with CNTs [76], interaction with catechin is favored, with improved selectivity and sensitivity of the CNT-GNP-Lac/SPE biosensor, which shows better performances than the other two biosensors.…”

Section: Calibration Curvementioning

confidence: 99%

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Assessment of the Antioxidant Activity of Catechin in Nutraceuticals: Comparison between a Newly Developed Electrochemical Method and Spectrophotometric Methods

Munteanu

Apetrei

2022

IJMS

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The analysis of antioxidants in different foodstuffs has become an active area of research, which has led to many recently developed antioxidant assays. Many antioxidants exhibit inherent electroactivity, and, therefore, the use of electrochemical methods could be a viable approach for evaluating the overall antioxidant activity of a matrix of nutraceuticals without the need for adding reactive species. Green tea is believed to be a healthy beverage due to a number of therapeutic benefits. Catechin, one of its constituents, is an important antioxidant and possesses free radical scavenging abilities. The present paper describes the electrochemical properties of three screen-printed electrodes (SPEs), the first one based on carbon nanotubes (CNTs), the second one based on gold nanoparticles (GNPs) and the third one based on carbon nanotubes and gold nanoparticles (CNTs-GNPs). All three electrodes were modified with the laccase (Lac) enzyme, using glutaraldehyde as a cross-linking agent between the amino groups on the laccase and aldehyde groups of the reticulation agent. As this enzyme is a thermostable catalyst, the performance of the biosensors has been greatly improved. Electro-oxidative properties of catechin were investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV), and these demonstrated that the association of CNTs with GNPs significantly improved the sensitivity and selectivity of the biosensor. The corresponding limit of detection (LOD) was estimated to be 5.6 × 10−8 M catechin at the CNT-Lac/SPE, 1.3 × 10−7 M at the GNP-Lac/SPE and 4.9 × 10−8 M at the CNT-GNP-Lac/SPE. The biosensors were subjected to nutraceutical formulations containing green tea in order to study their catechin content, using CNT-GNP-Lac/SPE, through DPV. Using a paired t-test, the catechin content estimated was in agreement with the manufacturer’s specification. In addition, the relationship between the CNT-GNP-Lac/SPE response at a specific potential and the antioxidant activity of nutraceuticals, as determined by conventional spectrophotometric methods (DPPH, galvinoxyl and ABTS), is discussed in the context of developing a fast biosensor for the relative antioxidant activity quantification.

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Section: Resultsmentioning

confidence: 99%