Electrochemically pretreated zeolite-modified carbon-paste electrodes for determination of linuron in an agricultural formulation and water

Siara, L.R.; Lima, Fábio de; Cardoso, Cláudia Andréa Lima; Arruda, Gilberto J.

doi:10.1016/j.electacta.2014.11.008

Cited by 37 publications

(18 citation statements)

References 46 publications

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“…The equations obtained from the linear regressions and the R 2 were i p a /µA = (2.70 ± 0.15) + (36.05 ± 0.59) × v 1/2 /V 1/2 s −1/2 ( R = +0.998) and i p c /µA = −(3.47 ± 0.28) − (27.22 ± 0.74) × v 1/2 /V 1/2 s −1/2 ( R = −0.996) for the anodic and cathodic peak currents, respectively. These results are as expected for the redox system investigated and suggest good electrochemical performance for the device proposed . The electrochemical active area of the working electrode was determined using the CV experiments and the Randles‐Sevcik equation, i p = (2.69 × 10 5 ) n 3/2 ACD 1/2 v 1/2 , where i p is the anodic ( i p a ) or cathodic ( i p c ) peak current in amperes, n is the number of electrons involved in the electrochemical reaction, A is the area of the electrode in cm 2 , C is the concentration of the analyte in mol cm −3 , D is the diffusion coefficient of the species (6.39 × 10 −6 cm 2 /s) , and v is the scan rate in V/s.…”

Section: Resultssupporting

confidence: 72%

Design of novel, simple, and inexpensive 3D printing‐based miniaturized electrochemical platform containing embedded disposable detector for analytical applications

et al. 2019

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This paper describes the development of a novel, simple, and inexpensive electrochemical device containing an integrated and disposable three‐electrode system for detection. The base of this platform consists on a PDMS structure containing microchannels which were prototyped using 3D‐printed molds. Pencil graphite leads were inserted into these microchannels and utilized as working, counter and reference electrodes in a novel design. Morphological analysis and electrochemical experiments with benchmark redox probes were carried out in order to evaluate the performance and characterize the miniaturized device proposed. Even using inexpensive materials and a simple fabrication protocol, the electrochemical platform developed provided good repeatability and reproducibility over a low cost (ca. $2 per device), acceptable lifetime (ca. 250 voltammetric runs) and extremely reduced consumption of samples and reagents (order of µL). As proof of concept, the analytical feasibility of the platform was investigated through the simultaneous determination of dopamine (DOPA) and acetaminophen (AC). The two analytes showed linear dependence on the concentration range from 1 to 15 µM and the LODs achieved were 0.21 µM for DOPA and 0.29 µM for AC. Moreover, the platform was successfully applied on the determination of DOPA and AC in spiked blood serum and urine samples. The results obtained with the device described here were better than some reports in literature that use more costly electrodic materials and complex modification steps for the detection of the same analytes.

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Section: Resultssupporting

confidence: 72%

Design of novel, simple, and inexpensive 3D printing‐based miniaturized electrochemical platform containing embedded disposable detector for analytical applications

et al. 2019

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“…The ratio between the anodic and cathodic peak currents ( I pa /I pc ) was ca . 1 for all the electrodes evaluated, which demonstrates the reversibility of the electrochemical process such as expected for the redox probes employed . Moreover, the peak currents showed linear dependence on the square root of the scan rates.…”

Section: Resultssupporting

confidence: 59%

“…To carry out the EIS measurements at fixed potential, an open‐circuit potential (OCP) of around 0.172 V (on average) with a potential perturbation of 10 mV within a frequency range from 10 mHz to 100 kHz was applied in the presence of 1 mmol L −1 each of K 3 Fe(CN) 6 /K 4 Fe(CN) 6 , which were used as redox probes .…”

Section: Methodsmentioning

confidence: 99%

Paper‐based Electrochemical Devices Coupled to External Graphene‐Cu Nanoparticles Modified Solid Electrode through Meniscus Configuration and their Use in Biological Analysis

et al. 2017

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This paper demonstrates, for the first time, the use of paper‐based electrochemical devices coupled to external solid working electrodes. The paper‐based electrochemical cells were fabricated using inexpensive and largely available office paper, according to a simple protocol that consists on the creation of hydrophobic barriers using paraffinized paper and preheated metal stamp. The counter and reference electrodes were integrated to the paper platform through the deposition of carbon and silver inks, respectively. The electrochemical paper analytical device (ePAD) was coupled to external glassy carbon rod electrode modified with reduced graphene oxide doped with Cu nanoparticles through meniscus configuration. The analytical usefulness of this electrochemical approach was demonstrated through the simultaneous determination of paracetamol and caffeine in biological samples. The analytes were successfully quantified in real urine samples and limits of detection of 24.6 nM (paracetamol) and 36.1 nM (caffeine) were obtained. The paper platform showed good stability (RSD of 1.07 % for the peak currents and 1.43 % for the peak potentials) and satisfactory performance. The use of solid electrodes coupled to paper electrochemical devices, firstly demonstrated here, opens new possibilities for the utilization of ePADs in electrochemistry and electroanalytical chemistry and offers advantages such as the extremely reduced consumption of reagents and the minimal generation of wastes.

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“…EIS experiments were employed to investigate the influence of EP on the electron transfer resistance ( R ct ) between solution and the electrode surface. This study was carried out using 1 mmol L −1 each of K 3 Fe(CN) 6 /K 4 Fe(CN) 6 as redox system . The values of R ct were obtained from Nyquist plot simulations through an equivalent circuit composed of resistors and capacitors .…”

Section: Resultsmentioning

confidence: 99%

“…The linear relationship between the peak current and the square root of the scan rate (insets of Figure A to 4D) suggests a diffusion‐controlled process. These results agree with the expected for the redox couple investigated . The electroactive areas (A eletroactive ) of the electrodes were obtained from the scan rate experiments using Randles‐Sevcik equation ( I p =±(2.69×10 5 ) n 3/2 ACD 1/2 υ 1/2 ) , where I p is the peak current ( I pa , anodic or I pc , cathodic) in amperes; n is the number of electrons involved; A is the electrode area in cm 2 ; C is the analyte concentration in the solution (mol cm −3 ); D is the diffusion coefficient (6.39×10 −6 cm 2 s −1 ) , and υ is the scan rate in V s −1 .…”

Section: Resultsmentioning

confidence: 99%

Simple and Inexpensive Electrochemical Platform Based on Novel Homemade Carbon Ink and its Analytical Application for Determination of Nitrite

2017

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In this work we present the development of a simple handmade approach for the easy fabrication of three‐electrode electrochemical devices based on newly in‐house developed carbon ink composed of graphite powder and polystyrene. Different proportions of graphite/polystyrene were investigated for the optimization of the ink. The counter and reference electrodes were produced using commercial carbon ink and silver glue. Scanning electron microscopy, electrochemical impedance spectroscopy and cyclic voltammetry were used to investigate the morphology and the electrochemical properties of the sensor. The results showed that the electroactive area of the optimized working electrode was ca. 2.35 times larger than its geometric area. The RSD values obtained for repeatability and reproducibility were 0.20% and 2.78%, respectively, which suggest no significant variation on the electrodes fabricated. The analytical feasibility of the electrode was tested through its application for the determination of nitrite in drinking water. The quantifications were successfully performed at levels below the maximum contaminant level established for nitrite. A limit of detection of 1.42 × 10−6 mol L−1 and recoveries of ca. 103 % were achieved. The results were validated using ion‐chromatography technique with good agreement. The performance of the unmodified sensor proposed here on nitrite determination was better than some recently reported modified electrodes obtained through complex procedures.

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Electrochemically pretreated zeolite-modified carbon-paste electrodes for determination of linuron in an agricultural formulation and water

Cited by 37 publications

References 46 publications

Design of novel, simple, and inexpensive 3D printing‐based miniaturized electrochemical platform containing embedded disposable detector for analytical applications

Design of novel, simple, and inexpensive 3D printing‐based miniaturized electrochemical platform containing embedded disposable detector for analytical applications

Paper‐based Electrochemical Devices Coupled to External Graphene‐Cu Nanoparticles Modified Solid Electrode through Meniscus Configuration and their Use in Biological Analysis

Simple and Inexpensive Electrochemical Platform Based on Novel Homemade Carbon Ink and its Analytical Application for Determination of Nitrite

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