Electrochemical detection in vitro and electron transfer mechanism of testosterone using a modified electrode with a cobalt oxide film

Moura, Silio Lima; Moraes, Rafael Rodrigues de; Santos, Marcos Antônio Pereira dos; Pividori, María Isabel; Lopes, José Arimateia Dantas; Moreira, Davyson de Lima; Zucolotto, Valtencir; Júnior, José Ribeiro dos Santos

doi:10.1016/j.snb.2014.05.104

Cited by 17 publications

(11 citation statements)

References 18 publications

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“…The two redox peaks centered at 0.2 V and 0.5 V are due to the electrochemical transitions between Co 3 O 4 /CoOOH and CoOOH/CoO 2 respectively at the electrode electrolyte interface. The electrochemical conversions are described in equations and are in good agreement with the literature ,

true Co_{3} normalO_{4} + OH^{-} + normalH_{2} normalO \leftrightarrow 3 CoOOH + normale^{-}

true CoOOH + OH \leftrightarrow CoO_{2} + normalH_{2} normalO + normale^{-}

…”

Section: Resultssupporting

confidence: 84%

Facile Electrodeposition of Hierarchical Co‐Gd₂O₃ Nanocomposites for Highly Selective and Sensitive Electrochemical Sensing of L–Cysteine

Premlatha

Selvarani

Bapu³

2018

ChemistrySelect

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Metal/metaloxide based composite materials have wide spread applications in electrochemical sensors and fuel cell applications. Hence, the present work is directed towards the fabrication of cost effective and highly sensitive electrode material for cysteine sensing. In this work, Co-Gd 2 O 3 nanocomposite is prepared by a simple electrodeposition route and used as electrochemical sensor material. The prepared nanocomposite materials are characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Xray Diffraction spectroscopy (XRD), Energy dispersive X-ray spectroscopy (EDX), and X-ray Photo electron spectroscopy (XPS). SEM images exhibited as hierarchical nanoflakes with open porous structure. EDX analysis showed the presence of cobalt and gadolinium. The reflections at 2q = 33 0 and 35.7 0 corresponds to the cubic structured Gd 2 O 3 nanoparticles validated the formation of nanocomposite. Electrooxidation of L-cysteine on Co and Co-Gd 2 O 3 was carried out using cyclic voltammetry technique. Upon addition of certain concentration of cysteine, the anodic peak current get increased with the simultaneous decline in the cathodic peak currents displayed the excellent electrocatalytic activity of Co-Gd 2 O 3 nanocomposite. The chronoamperometric experiments were performed to derive the analytical parameters like sensitivity, limit of detection and linear range. The reproducibility, stability and real sample analysis was studied using chronoamperometry.[a] S. Premlatha

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true Co_{3} normalO_{4} + OH^{-} + normalH_{2} normalO \leftrightarrow 3 CoOOH + normale^{-}

true CoOOH + OH \leftrightarrow CoO_{2} + normalH_{2} normalO + normale^{-}

…”

Section: Resultssupporting

confidence: 84%

Facile Electrodeposition of Hierarchical Co‐Gd₂O₃ Nanocomposites for Highly Selective and Sensitive Electrochemical Sensing of L–Cysteine

Premlatha

Selvarani

Bapu³

2018

ChemistrySelect

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“…As shown in Figure S19, the 150-CoO/SiO x /n-Si photoanode having 10 nm ALD CoO x thickness showed rapidly decreasing photocurrent density during a chronoamperometry stability test. Since the phase transition of a metal-oxide catalyst is accompanied by a volume change, flaws can be generated during the film transition and these flaws can cause exposure of vulnerable Si. , In addition, it was also noticed that the exposed Si surface was etched by KOH during water oxidation as depicted in the plan-view SEM images of Figure S20a. Such etched rough Si surface then can weaken the adhesion between CoO x and the Si surface.…”

Section: Resultsmentioning

confidence: 99%

Hole-Selective CoO_x/SiO_x/Si Heterojunctions for Photoelectrochemical Water Splitting

Jung

Lee

et al. 2018

ACS Catal.

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Cobalt oxide (CoO x ), an earth-abundant and low-cost oxygen evolving catalyst (OEC), has notable advantages as a top protection layer of photoanodes for solar-driven water oxidation because of its desirable durability. However, cobalt oxides exist as various phases, such as Co(II)O, Co2(III)O3, Co3(II,III)O4, and the (photo)electrochemical properties of CoO x are significantly governed by its phase. Atomic layer deposition (ALD) is a suitable method to form a multifunctional layer for photoelectrochemical (PEC) water splitting because it allows direct growth of a conformal high-quality film on various substrates as well as facile control over its chemical phases by adjusting the deposition conditions. Here, a well-controlled CoO x /SiO x /n-Si heterojunction prepared by ALD is demonstrated for solar-driven water splitting. The phase of the ALD CoO x films can be easily controlled from CoO to Co3O4 by varying the deposition temperature. In addition, this systematic study reveals that its energetic as well as electrochemical properties are changed significantly with the phase. Whereas CoO grown at 150 °C produces high photovoltage by building desirable hole-selective heterojunctions with n-Si, Co3O4 formed at 300 °C has a better catalytic property for water oxidation. To address this competitive correlation, we developed a double-layered (DL) ALD CoO x film that has advantages of both CoO and Co3O4. The DL ALD CoO x /SiO x /Si heterojunction photoanode produces a photocurrent density of 3.5 mA/cm2 without a buried junction and maintains a saturating current density of 32.5 mA/cm2 without noticeable degradation during 12 h in 1 M KOH under a simulated 1 sun illumination.

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“…Data in Table 5. [182][183][184][185][186][187][188][189][190] shows the comparison between different electrochemical sensors for TN. Results given by Liu et al [181] for molecularly imprinted polymer /electrochemically grafted on graphene-oxide sheets modified electrode provide the lowest LOD of 0.4 fM.…”

Section: A D V a N C E D O N L I N Ementioning

confidence: 99%

Research developments in carbon materials based sensors for determination of hormones

Manjunatha

Tigari

Hareesha

et al. 2021

J. Electrochem. Sci. Eng.

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Various carbon-based sensors (graphene, carbon nanotubes, graphite, pencil graphite, glassy carbon, etc.) have distinctive behavior and a broad range of importance for identifying sex hormones like estriol, estradiol, estrone, progesterone, and testosterone. The current review emphasizes voltammetric, amperometric, and electrochemical impedance spectroscopic methods for detecting some of these hormones. The existence, structural aspects, nature, and biological importance of each hormone were analyzed in detail and their analysis with different electroanalytical methods was considered. Unique methodologies and innovations of electrochemical sensors for hormones based on carbon materials modified by different agents were examined. In this review, the interaction among various sensor materials and analytes in different supporting electrolyte media is premeditated. The most important significances of the electroanalytical methodologies were discussed based on sensor selectivity, sensitivity, stability, the limit of detection, repeatability, and reproducibility.

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Electrochemical detection in vitro and electron transfer mechanism of testosterone using a modified electrode with a cobalt oxide film

Cited by 17 publications

References 18 publications

Facile Electrodeposition of Hierarchical Co‐Gd₂O₃ Nanocomposites for Highly Selective and Sensitive Electrochemical Sensing of L–Cysteine

Facile Electrodeposition of Hierarchical Co‐Gd₂O₃ Nanocomposites for Highly Selective and Sensitive Electrochemical Sensing of L–Cysteine

Hole-Selective CoO_x/SiO_x/Si Heterojunctions for Photoelectrochemical Water Splitting

Research developments in carbon materials based sensors for determination of hormones

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Electrochemical detection in vitro and electron transfer mechanism of testosterone using a modified electrode with a cobalt oxide film

Cited by 17 publications

References 18 publications

Facile Electrodeposition of Hierarchical Co‐Gd2O3 Nanocomposites for Highly Selective and Sensitive Electrochemical Sensing of L–Cysteine

Facile Electrodeposition of Hierarchical Co‐Gd2O3 Nanocomposites for Highly Selective and Sensitive Electrochemical Sensing of L–Cysteine

Hole-Selective CoOx/SiOx/Si Heterojunctions for Photoelectrochemical Water Splitting

Research developments in carbon materials based sensors for determination of hormones

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Resources

About

Facile Electrodeposition of Hierarchical Co‐Gd₂O₃ Nanocomposites for Highly Selective and Sensitive Electrochemical Sensing of L–Cysteine

Facile Electrodeposition of Hierarchical Co‐Gd₂O₃ Nanocomposites for Highly Selective and Sensitive Electrochemical Sensing of L–Cysteine

Hole-Selective CoO_x/SiO_x/Si Heterojunctions for Photoelectrochemical Water Splitting