Detection Of Catechol Research Articles

Selective sensing of catechol based on a fluorescent nanozyme with catechol oxidase activity

Nanozymes, an unusual category of nanomaterials possessing enzymatic properties, and have generated considerable interest regarding their application feasibilities on several important fronts. In the present work, an innovative sensing device for catechol was established ground on a fluorescent nanozyme (Cu-BDC-NH2) that exhibited catechol oxidase activity. The fluorescent nanozyme combines both functions of catechol recognition and response signal output, and can realize the sensing of catechol without the addition of other chromogenic agents. In the existence of Cu-BDC-NH2, catechol can be oxidized efficiently to produce quinones or polymers with strong electron absorption capacity, which immediately results in efficient fluorescence quenching of Cu-BDC-NH2. However, other common phenolic compounds, such as phenol, the other two diphenols (hydroquinone and resorcinol), phloroglucinol, and chlorophenol, do not result in efficient fluorescence quenching of Cu-BDC-NH2. The method shows a nice linear relationship between catechol concentration prep the fluorescence intensity of Cu-BDC-NH2 in the scope of 0–10 μM, with a detection limit of 0.997 μM. The detection of catechol in actual water samples has also achieved the satisfactory consequences, which provides a new strategy for the convenient and selective detection of catechol.

Disposable Pencil Lead as an Electrochemical Transducer for Monitoring Catechol in River and Tap Water

A cheap and disposable pencil graphite electrode (PGE) was developed by the incorporation of amine groups (Am-PGE-1). A further improvement in the performance was observed when the aminated electrode (Am-PGE-1) was activated by applying a negative potential scan (Am-PGE-2). The electrochemical transport properties were evaluated through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The Nyquist plot showed a reduced charge transfer resistance value of 24.3 Ω for Am-PGE-2, while it was 95.1 Ω for bare PGE. Thus, Am-PGE-2 was used as a sensing platform for the detection of catechol. It was found that the electrochemical response of catechol oxidation at Am-PGE-2 was twice than the current obtained for bare PGE. Additionally, the effect of pH of the supporting electrolyte and reaction kinetic were studied. The heterogeneous electron transfer rate constant was calculated to be 0.01 s−1. Moreover, CV study revealed that the redox reaction of catechol was a quasi-reversible and diffusion-controlled process. The square wave voltammetry (SWV) technique was applied for the quantitative determination of catechol. The peak current showed a linear dependency on the concentration of catechol from 3 to 150 µM. Furthermore, the analyte could be detected as low as 3.86 µM. Likewise, the sensor demonstrates a good selectivity towards the target analyte than the other possible interfering molecules or ions. Aiming to examine practical applicability, real samples, such as river and household tap water, were tested by using the proposed transducer, and the satisfactory recoveries demonstrate the effectiveness of Am-PGE-2 in real life applications.

A Magnetite Composite of Molecularly Imprinted Polymer and Reduced Graphene Oxide for Sensitive and Selective Electrochemical Detection of Catechol in Water and Milk Samples: An Artificial Neural Network (ANN) Application

In the present study, a stable and more selective electrochemical sensor for catechol (CC) detection at magnetic molecularly imprinted polymer modified with green reduced graphene oxide modified glassy carbon electrode (MIP/rGO@Fe3O4/GCE). Two steps have been applied to achieve the imprinting process: (1) adsorption of CC on the surface of the polypyrrole (Ppyr) during the polymerization of pyrrole and (2) the green extraction of the template (CC) from the mass produced. Hence, the present paper doesn’t present the first use of MIP technology for CC identification but, it presents a new extraction process. The MIP/rGO@Fe3O4/GCE was characterized by voltammetry techniques and exhibited a wide linear range from1 50 μM of CC while the detection limits were estimated to be around 4.18 nM CC and limit of quantification in the range of 12.69 nM CC. Furthermore, the prepared MIP-based sensor provided outstanding electroanalytical performances including high selectivity, stability, repeatability, and reproducibility. For the accurate estimation of CC concentrations, an artificial neural network (ANN) was developed based on the findings of the study. The MIP/rGO@Fe3O4/GCE exhibits excellent stability with a very important selectivity and sensitivity. The analytical testing of the modified electrode has been analyzed in water and commercial milk samples and provided adequate recoveries.

Amperometric biosensor based on immobilized laccase onto Cys-Ag@Fe3O4 magnetic nanoparticles for selective catechol detection

Amperometric biosensor based on immobilized laccase onto Cys-Ag@Fe3O4 magnetic nanoparticles for selective catechol detection

Electrochemical detection and quantification of catechol based on a simple and sensitive poly(riboflavin) modified carbon nanotube paste electrode

In the present research work, selective and sensitive catechol (CT) detection and quantification were shown in the presence of resorcinol (RS) in 0.2 M phosphate buffer (PB) solution by preparing a low-cost, simple, and green carbon nanotube paste electrode (CNTPE) surface activated with electropolymerized riboflavin (PRF). The morphological, conductivity, and electrochemical features of the modified electrode (PRFMCNTPE) and bare carbon nanotube paste electrode (BCNTPE) materials were analyzed using electrochemical impedance spectroscopy (EIS), field emission scanning electron microscopy (FE-SEM), cyclic voltammetry (CV), and differential pulse voltammetry (DPV). The PRF-activated electrode displays outstanding sensitivity, stability, selectivity, reproducibility, and repeatability for the redox feature of CT with improved electrochemical current and declined electrochemical potential compared to BCNTPE. The peak currents of CT are correlated to the different CT concentrations (CV method: 6.0–60.0 μM & DPV method: 0.5–7.0 μM), and the obtained detection limit (DL) and quantification limit (QL) are found to be 0.025 μM and 0.085 μM (CV method) and 0.0039 μM and 0.0132 μM (DPV method), respectively. The prepared PRFMCNTPE material was advantageous for the examination of CT in environmentally important tap water sample as a real-time application.

Metal-organic-framework-derived Ni3ZnC0.7 materials for highly sensitive electrochemical detection of catechol

Metal-organic-framework-derived Ni3ZnC0.7 materials for highly sensitive electrochemical detection of catechol

Porous carbon fabricated by a residue from Longquan lignite ethanolysis as an electrochemical sensor for simultaneous detection of hydroquinone and catechol in the presence of resorcinol

Catechol (CC), resorcinol (RS), and hydroquinone (HQ) are regarded as both important raw materials widely applied in chemical industry and highly toxic organic pollutants, so accurately detecting them is very necessary. In this work, Longquan lignite residue with low added value was fabricated as highly active porous carbons (PCs). The morphology, specific surface area (SSA), and electrocatalytic oxidation performance of the PCs prepared at different activated temperatures (600 ∼ 900 °C) were studied in detail. All PCs have different portions of micropores and mesoporous, and their SSAs can reach up to 3028 m2/g. Such well-developed microporous and mesoporous structures can provide abundant active sites to facilitate ion and electron transport, and thereby improving the electrocatalytic performance. Among them, the PC prepared at 800 °C shows the best detection performance. It can successfully detect HQ and CC simultaneously in the presence of RS, with detection limits of 0.15 and 0.81 µM for HQ, 0.09 and 0.53 µM for CC comparable to some graphene-based electrochemical sensors. Additionally, the constructed electrochemical sensor also displays a good reproducibility, stability, and anti-interference, which makes it a promising candidate material for monitoring phenolic compounds in actual water samples.

MOF-derived Bi@C nanocomposites electrode simultaneous detection of hydroquinone and catechol

MOF-derived Bi@C nanocomposites electrode simultaneous detection of hydroquinone and catechol

Electrochemically polymerized glutamine-activated graphite paste surface as a green biosensor for sensitive catechol detection in water samples

Electrochemically polymerized glutamine-activated graphite paste surface as a green biosensor for sensitive catechol detection in water samples

Catechol detection based on a two-dimensional copper-based metal-organic framework with high polyphenol oxidase activity

In this work, a novel sensing strategy for catechol was successfully developed based on a two-dimensional copper-based metal-organic framework (2D Cu-MOF) with high polyphenol oxidase activity. The 2D Cu-MOF was prepared from dimethylimidazole and Cu 2+ by stirring in a mixture solvent of methanol and water. We firstly found that the 2D Cu-MOF exhibited high polyphenol oxidase (PPO) activity by catalyzing the typical PPO substrate to produce a red color. And the PPO activity of the 2D Cu-MOF was higher than those of the other two reported PPO-mimicking enzymes at the same mass concentration. Subsequently, based on the effective PPO activities of the 2D Cu-MOF, we established a simple and rapid colorimetric method for detecting catechol with a detection limit of 0.35 μg·mL −1 . This method was also used to detect catechol in city water with satisfying results.

Flexible electrochemical sensor constructed using an active copper center instead of unstable molybdenum carbide for simultaneous detection of toxic catechol and hydroquinone

A new electrochemical sensor based on a Cu-CuO@MoOx-modified polyethylene terephthalate electrode spin coated with PEDOT (Cu-CuO@MoOx-PEDOT/PET) was developed for simultaneous determination of catechol (CT) and hydroquinone (HQ). A zerovalent copper and copper(II) oxide intercalated molybdenum oxide MoOx (x = 2 or 3) hybrid nanomaterial (Cu-CuO@MoOx) by introducing active copper catalytic centers into the Mo2C@MoOx system based on unstable Mo2C, and replaced Mo2C using a simple hydrothermal method. At room temperature, the Cu-CuO@MoOx-PEDOT/PET electrode demonstrated the lowest detection limits of 0.216 and 0.221 μM for CT and HQ (S/N = 3), respectively. In addition, the applicability of this method was proven by the recovery of CT and HQ in spiked tap water samples. The Cu-CuO@MoOx-PEDOT/PET flexible electrode had strong anti-interference ability, good repeatability and long-term stability. It was used in the detection of CT and HQ in Nanjing tap water, the recoveries of CT and HQ calculated from the i–t curve were 99.36 % and 97.56 %, respectively. Most importantly, the flexible electrode could still maintain relatively stable electrochemical responses under different bending and folding conditions, and the obtained relative standard deviations (RSDs) were 2.78 % and 1.53 %, respectively. This flexible property holds promise for the construction of wearable electrochemical sensors.

Effect of Acridine Orange on Improving the Electrochemical Performance of Tyrosinase Adsorbed Sulfide Minerals Based Catechol Biosensor

AbstractA highly sensitive and selective electrochemical biosensor for catechol (CC) detection was developed by immobilizing tyrosinase (TYR) on a glassy carbon electrode (GCE) modified with sulfide minerals (SFMs) in the co‐adsorption of acridine orange (AO). The sensor employed natural SFMs as the substrate material and utilized AO as a molecular recognition probe to create synergy effect for TYR to detect catechol. The developed TYR/AO/SFMs/GCE biosensors were characterized by scanning electron microscope, energy dispersive analysis of X‐rays spectroscopy, X‐ray diffraction spectra, X‐ray fluorescence, and electrochemical analysis. The results show that the sensors have excellent electrochemical activity for the detection of catechol (CC) under optimized conditions. The linear ranges were 0.1–50 μM, 0.1–10 μM, 0.1–50 μM and 0.1–100 μM for galena, pyrite, chalcopyrite and sphalerite, respectively, with the detection limits of 1.18 μM, 0.29 μM, 0.54 μM and 0.68 μM, respectively. The sensors also have good reproducibility, stability, repeatability and anti‐interference ability. AO is essential to increase the adsorbed amount and provides suitable orientation of the adsorbed TYR on these sulfide minerals’ surfaces. In consideration of cost‐effective and rich resources of sulfide minerals, easily physical adsorption method, combination of organic dye, minerals and enzymes, this strategy paves a new way to design other novel electrochemical biosensors.

Poly DY 11/Zn/CuO modified electrochemical sensor for the detection of catechol and hydroquinone: A voltammetric study

In the present work, Zn doped CuO nanoparticles (Zn/CuO Npcs) was synthesized by co-precipitation method for the fabrication of electrode towards the detection of Catechol (CA) and Hydroquinone (HY). The particle size and surface morphology of Zn/CuO Npcs was characterized by X-ray diffraction technique (XRD) and Scanning electron microscopy (SEM). Further cyclic voltammetric technique was used for the electropolymerization of Direct Yellow 11 (DY 11) on the surface of Zn doped CuO modified carbon paste electrode (MCPE) and applied for the determination of CA and HY at optimum pH 7.4. After the modification, the PolyDY11/Zn/CuO electrode exhibits very stable and sensitive current responses towards the CA and HY. The various parameters like scan rate, pH and concentration of both CA and HY were studied. Simultaneous determination of CA and HY in presence of Resorcinol (RE) was investigated by using cyclic voltammetry, Selectivity study of CA and HY was studied using the differential pulse voltametric technique. The fabricated electrode exhibits adsorption controlled and limit of detection (LOD) calculated for CA and HY in range (10–90 μM) was found to be CA(6 μM) and HY(7 μM) respectively, The real sample analysis in tap water showed better recovery between 90 and 96% for CA and 90–94% for HY respectively.

3D hierarchical LDHs-based Janus micro-actuator for detection and degradation of catechol.

Micro/nanomotors that combine the miniaturization and autonomous motion have attracted much research interest for environmental monitoring and water remediation. However, it is still challenging to develop a facile route to produce bifunctional micromotors that can simultaneously detect and remove organic pollutants from water. Herein, we developed a novel Janus micromotor with robust peroxide-like activity for simultaneously colorimetric detection and removal of catechol from water. Such laccase (Lac) functionalized Janus micromotor consisted of calcined MgAl-layered double hydroxides (MgAl-CLDHs) nanosheets and Co3O4-C nanoparticles (Lac-MgAl-CLDHs/Co3O4-C), revealing unique 3D hierarchical microstructure with highly exposed active sites. The obtained Janus micromotors exhibited autonomous motion with a maximum velocity of 171.83±4.07µm/s in the presence of 7wt% H2O2 via a chemical propulsion mechanism based on the decomposition of H2O2 by Co3O4-C layer on the hemisphere surface of Janus micromotors. Owing to the combination of autonomous motion and high peroxide-like activity, Lac-MgAl-CLDHs/Co3O4-C Janus micromotors could sensitively detect catechol with the limit of detection of 0.24μM. In addition, such Janus micromotors also could quickly degrade catechol by •OH generated from a Fenton-like reaction. It is a first step towards using autonomous micromotors for highly selective, sensitive, and facile detection and quick removal of catechol from water.

Synchronized electrochemical detection of hydroquinone and catechol in real water samples using a Co@SnO2-polyaniline composite.

The conductive composite Co@SnO2-PANI was successfully synthesized using hydrothermal/oxidative synthesis. Using differential pulse voltammetry, a glassy carbon electrode modified with a CoSnO2-PANI (polyaniline)-based electrochemical biosensor has been created for the quick detection of two phenolics, hydroquinone (Hq) and catechol (Cat). Differential pulse voltammetry (DPV) measurements revealed two well-resolved, strong peaks for GCE@Co-SnO2-PANI, which corresponded to the oxidation of Hq and Cat at 275.87 mV and +373.76 mV, respectively. The oxidation peaks of Hq and Cat mixtures were defined and separated at a pH of 8.5. High conductivity and remarkable selectivity reproducibility was tested by electrochemical impedance spectroscopy, chronoamperometry, and cyclic voltammetry techniques in standard solution and real water samples. The proposed biosensor displayed a low detection limit of 4.94 nM (Hq) and 1.5786 nM (Cat), as well as a large linear range stretching from 2 × 10-2 M to 2 × 10-1 M. The real-sample testing showed a good recovery for the immediate detection of Hq (96.4% recovery) and Cat (98.8% recovery) using the investigated sensing apparatus. The synthesized biosensor was characterized by XRD, FTIR, energy dispersive spectroscopy and scanning electron microscopy.

Controlling supramolecular structures in iron tetrasulfonated phthalocyanine films through pH variation: implications for thin-film device performance.

Improving the performance of thin film-based devices is a crucial factor for their successful application, mainly for organic electronic semiconductors. The adjustment of supramolecular structuring of thin films plays a role in the optical and electrical properties. In this sense, we investigated how various pH values, such as 2.5, 6.0, and 9.0, of the solutions influenced the growth of iron tetrasulfonated phthalocyanine (FeTsPc) Layer-by-Layer (LbL) films and their respective supramolecular structures as well as their electrochemical properties. The supramolecular structures were evaluated via UV-vis absorption spectroscopy, quartz crystal microbalance (QCM), micro-Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and cyclic voltammetry. The different pH values of the solution induce different degrees of molecular aggregation for FeTsPc (monomer, dimer, and aggregate formation). For instance, the higher the pH, the higher the aggregation. Films produced at pH 2.5 were organized preferentially with the molecules perpendicular to the substrate, while films at pH 6.0 and 9.0 were organized preferentially with the molecules parallel to the substrate. Besides, the film produced at pH 2.5 results in higher film thickness, higher stability, and better electrocatalytic behavior for the electrochemical detection of catechol. The results presented here enhance the understanding of nanostructured films, helping to harness supramolecular organization to improve the performance of thin-film devices.

Immobilization of laccase on Fe3O4@MF-CNTs for the rapid and sensitive biosensing of catechol

An Fe3O4@MF-CNTs-Lac biosensor was developed for rapid and sensitive detection of catechol.

A highly explicit electrochemical biosensor for catechol detection in real samples based on copper-polypyrrole.

Catechol is a pollutant that can lead to serious health issues. Identification in aquatic environments is difficult. A highly specific, selective, and sensitive electrochemical biosensor based on a copper-polypyrrole composite and a glassy carbon electrode has been created for catechol detection. The novelty of this newly developed biosensor was tested using electrochemical techniques. The charge and mass transfer functions and partially reversible oxidation kinetics of catechol on the redesigned electrode surface were examined using electrochemical impedance spectroscopy and cyclic voltammetry scan rates. Using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry, the characteristics of sensitivity (8.5699 μA cm-2), LOD (1.52 × 10-7 μM), LOQ (3.52 × 10-5 μM), linear range (0.02-2500 μM), specificity, interference, and real sample detection were investigated. The morphological, structural, and bonding characteristics were investigated using XRD, Raman, FTIR, and SEM. Using an oxidation-reduction technique, a suitable biosensor material was produced. In the presence of interfering compounds, it was shown that it was selective for catechol, like an enzyme.

Electrochemical and optical dual-mode detection of phenolic compounds using MnO2/GQD nanozyme

Phenolic compounds (PCs) have been widely employed in industrial activities and have also been found at threatening levels in natural environments, posing risks to human health and the environment. As a consequence, there is an increasing demand for the development of simple and sensitive detection methods of such pollutants. In this work, we report the use of manganese dioxide and graphene quantum dot (MnO2/GQD) composites as a dual-functional sensing platform for the electrochemical and colorimetric detection of catechol (CC) and dopamine (DA), two important PCs. Regarding the electrochemical detection, differential pulse voltammetry showed a linear relationship between current signal intensity and concentration of DA and CC over the linear ranges of 0.5–100 μM and 5–150 μM, with limits of detection of 0.05 µM and 0.09 µM for DA and CC, respectively. In addition, the composite was employed for the colorimetric detection of CC and DA through the oxidase mimic activity of the MnO2/GQD in the presence of 3,5,3,5-tetramethylbenzidine (TMB). Analysis in real samples showed that the MnO2/GQD composite can be used for the sensitive detection of CC and DA in river samples. The high surface area and improved electrochemical properties of the MnO2/GQD were demonstrated to be beneficial for dual sensing applications of phenolic compounds.

Electrochemical biosensor based on tyrosinase-immobilized phase-change microcapsules for ultrasensitive detection of phenolic contaminants under in situ thermal management

Aiming at enhancing the detection of phenolic contaminants in high-temperature environments, we developed a thermoregulatory electrochemical biosensor based on the tyrosinase-immobilized electroactive phase-change microcapsules. The microcapsules were fabricated by engulfing n-eicosane as a phase-change material core in a TiO2 shell, followed by depositing with an electroactive hybrid layer comprising the polypyrrole matrix and tyrosinase-immobilized Fe3O4 nanoparticles. The resultant microcapsules show a well-defined core–shell microstructure and a regular spherical morphology, together with the desired chemical compositions and structures. Acting as a biosensing electrode material, the microcapsules exhibit a high latent heat capacity of around 150 J/g to implement microenvironmental temperature regulation for the biosensor through reversible phase transitions of their n-eicosane core. This enables the developed biosensor to obtain a higher enzyme activity and more sensitive biosensing performance at high assay temperatures when compared to conventional tyrosinase biosensors, resulting in a high sensitivity of 0.102 (µA·L)/µmol and a lower detection limit of 3.409 µmol/L for catechol detection. Based on a unique integration of phase-change microcapsules and immobilized tyrosinase in the working electrode, the electrochemical biosensor developed in this study has found a practical application for high-sensitive reorganization and high-accurate determination of phenolic contaminants in industrial wastewaters over a wide working temperature range.