p_Aminophenol, namely 4-aminophenol (4-AP), is an aromatic compound including hydroxyl and amino groups contiguous together on the benzene ring, which are suitable chemically reactive, amphoteric, ...and alleviating agents in nature. Amino phenols are appropriate precursors for synthesizing oxazoles and oxazines. However, since the toxicity of aniline and phenol can harm human and herbal organs, it is essential to improve a reliable technique for the determination of even a trace amount of amino phenols, as well as elimination or (bio)degradation/photodegradation of it to protect both the environment and people's health. For this purpose, various analytical methods have been suggested up till now, including spectrophotometry, liquid chromatography, spectrofluorometric and capillary electrophoresis, etc. However, some drawbacks such as the requirement of complex instruments, high costs, not being portable, slow response time, low sensitivity, etc. prevent them to be employed in a wide range and swift in-situ applications. In this regard, besides the efforts such as (bio)degradation/photodegradation or removal of 4-AP pollutants from real samples, electroanalytical techniques have become a promising alternative for monitoring them with high sensitivity. In this review, it was aimed to emphasize and summarize the recent advances, challenges, and opportunities for removal, degradation, and electrochemical sensing 4-AP in real samples. Electroanalytical monitoring of amino phenols was reviewed in detail and explored the various types of electrochemical sensors applied for detecting and monitoring in real samples. Furthermore, the various technique of removal and degradation of 4-AP in industrial and urban wastes were also deliberated. Moreover, deep criticism of multifunctional nanomaterials to be utilized as a catalyst, adsorbent/biosorbent, and electroactive material for the fabrication of electrochemical sensors was covered along with their unique properties. Future perspectives and conclusions were also criticized to pave the way for further studies in the field of application of up-and-coming nanostructures in environmental applications.
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Nickel-based metal-organic skeletal materials (Ni-MOFs) are a new class of inorganic materials that have aroused attention of investigators during past couple of years. They offer advantages such as ...high specific surface area, structural diversity, tunable framework etc. This assorted class of materials exhibited catalytic activity and electrochemical properties and display wide range of applications in the fields of electrochemical sensing, electrical energy storage and electrocatalysis. In this context, the presented review focuses on strategies to improve the electrochemical performance and stability of Ni-MOFs through the optimization of synthesis conditions, the construction of composite materials, and the preparation of derivatives of precursors. The review also presents the applications of Ni-MOFs and their derivatives as electrochemical sensors, energy storage devices, and electrocatalysts. In addition, the challenges and further electrochemical development prospects of Ni-MOFs have been discussed.
An overview about the recent progresses in the electrochemical applications of nickel based metal organic frameworks (Ni-MOFs) explored with the context with electrochemical sensors, energy storage devices, and electrocatalysts. Display omitted
•An overview about the recent progresses in the electrochemical applications Ni-MOFs explored.•Various facets of Ni-MOFs as sensors, energy storage devices and electrocatalysts investigated.•Plausible strategies to improve the electrochemical performances of Ni-MOFs discussed.
The unique coupling between B and N atoms as a result of co-doping could result in novel electronic structures in graphene. In this work, role of synergistic coupling effect of boron and nitrogen ...while codoping by systematically varying the concentrations of boron and nitrogen precursors is used to analyse the effects on electrochemical sensing of dopamine and hydrogen peroxide and supercapacitance performance. When compared with single doped samples (B and N), the codoped samples exhibited better supercapacitance and electrochemical sensing. Different boron and nitrogen doped graphene (BNGn (n = 1-5)) samples have been synthesized to modulate the electronic structure and surface states in order to improve the electrochemical performances. BNG5 sample shows a high specific capacitance of 378.7 F/g at 0.145 A/g in 1.0 M H2SO4, a threefold increase over single-doped graphene due to the high boron content that resulted in the highest B–N content. These samples show 92.11% cycling retention after 2000 cycles. Thus, B,N codoped samples can be tailored to be promising supercapacitor electrode materials. Excellent nonenzymatic dopamine and hydrogen peroxide sensing performance shown by BNG2 sample with 0.15 μM and 0.018 μM limit of detection (LOD) in 0–120 μM and 1–12 mM range respectively, was due to the high content of BC2O, BCO2, graphitic and oxidized N dopant species. Thus, this work brings to fore the different moieties which play crucial role in enhancing the supercapacitance (B–N, BC2O) and sensing behavior (oxidized dopants) for B,N codoped graphene. This opens up avenues to tailor doped graphene for specific applications.
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•Study synergic coupling of B,N in graphene with systematic concentration variation.•BN codoped graphene showed better supercapacitance (378.7 F/g) over single doped.•Excellent electrochemical dopamine sensing (0.15 μM) observed in BN codoped samples.•Excellent electrochemical H2O2 detection (0.018 μM) observed in BN codoped samples.•Chemical moieties enhancing supercapacitance and sensing applications are highlighted.
It is widely accepted that nanotechnology attracted more interest because of various values that nanomaterial applications offers in different fields. Recently, researchers have proposed ...nanomaterials based electrochemical sensors and biosensors as one of the potent alternatives or supplementary analytical tools to the conventional detection procedures that consumes a lot of time. Among different nanomaterials, researchers largely considered magnetic nanomaterials (MNMs) for developing and fabricating the electrochemical (bio)sensors for numerous utilizations. Among several factors, healthier and higher quality foods are the most important preferences of consumers and manufacturers. For this reason, developing new techniques for rapid, precise as well as sensitive determination of components or contaminants of foods is very important. Therefore, developing the new electrochemical (bio)sensors in food analysis is one of the key and effervescent research fields. In this review, firstly, we presented the properties and synthesis strategies of MNMs. Then, we summarized some of the recently developed MNMs-based electrochemical (bio)sensors for food analysis including detecting the antioxidants, synthetic food colorants, pesticides, heavy metal ions, antibiotics and other analytes (bisphenol A, nitrite and aflatoxins) from 2010 to 2020. Finally, the present review described advantages, challenges as well as future directions in this field.
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•This review describes the electrochemical applications of magnetic nanomaterials.•Electrochemical sensors are reviewed for food analysis.•Electrochemical biosensors are reviewed for food analysis.
•Specific recognition of Ru2+ is applied to the construction of 5'-GMP sensor.•To realize the identification of freshness, nanocomposites were developed.•Based on the electrochemical sensor can ...realize the rapid detection needs.•The sensor was successfully applied in actual sample testing.
5′-Guanosine monophosphate (5′-GMP) is one main source of freshness in broths. Herein, an electrochemical platform based on a novel ternary nanocomposite glassy carbon electrode modified with advantageously-united gold nanoparticles, 2,2′-bipyridine hydrated ruthenium (Ru(bpy)2Cl2) and sulfonated multi-walled carbon nanotubes (SMWCNTs)was prepared and used to detect 5′-GMP. After conditions optimization, the best performance of the electrochemical sensor was found in acidic media, including high specificity, sensitivity and selectivity. The electrochemical sensor exhibited a wide linear range under the optimal conditions. The enhanced sensitivity of this sensor was attributed to the Ru(bpy)2Cl2 and functionalized SMWCNTs that provided high electrical conductivity and electrocatalytic properties during electrochemical reaction. Precise analysis of 5′-GMP in actual broth samples showed satisfactory recovery. Thus, the sensor can be used in the market and food enterprises.
•Incorporation of AC with CoWO4 to improve inherent redox activity towards oxidation of TBPA.•Utilization of ANN modeling for predictive assessment of DPV based TBPA sensing.•DFT based confirmation ...of non-covalent interaction between TBPA and CoWO4.
The escalating levels of environmental pollution, particularly from commercially used products, highlight the imperative of efficient sensor technologies to facilitate timely and effective remediation strategies. Herein, a simple method is proposed to enhance the electrochemical performance of CoWO4 structures by coupling them with activated carbon (AC) for direct tetrabromobisphenol A (TBPA) oxidation. The systematic comparison shows that incorporation of AC with CoWO4 not only improves the overall effective surface area (ESA) of the catalyst by 1.8-fold but also improves the cyclic voltammetry (CV) based irreversible oxidation current by 2.0-fold owing to improved conductivity and surface characteristics. Differential pulse voltammetry (DPV) based optimization of the sensory characteristics confirmed robust electrocatalytic TBPA oxidation within a 0.1 to 1.0 µM concentration range, achieving a 0.024 µM detection limit within PBS (0.1 M) (pH 5.0). Moreover, density functional theory (DFT) analysis confirms the non-covalent interaction favorability between TBPA and CoWO4 surface, validating TBPA’s easy adsorption onto the catalytic surface and, thus, facilitated electron mobility between the molecule and the catalyst during the surface oxidation process. The DPV sensing interpreted using machine learning (ML) algorithms confirmed the detection accuracy of the developed sensor. Among the adopted models, artificial neural networks (ANN) achieved the highest R2 score (0.9659) and the lowest values across Mean Squared Error (MSE), Mean Absolute Error (MAE), and Root Mean Squared Error (RMSE) error matrices confirming its suitability in deciphering DPV correlations.
Integrating ANN with DPV based electrocatalytic oxidation sensing underscores machine learning’s potential in analyzing complex electrochemical signatures, thus advancing intelligent sensing for precise environmental monitoring.
This work focuses on the study of nanomaterial-based sensors for mycotoxins detection. Due to their adverse effects on humans and animals, mycotoxins are heavily regulated, and the foodstuff and feed ...stocks with a high probability of being contaminated are often analyzed. In this context, the recent developments in graphene-based electrochemical sensors for mycotoxins detection were examined. The mycotoxins' toxicity implications on their detection and the development of diverse recognition elements are described considering the current challenges and limitations.
•Graphene-based nanomaterials (GBN) were used for the detection of mycotoxins.•The recent developments of GM-based EC sensors are described for mycotoxins detection.•GM-based EC sensors have high detection ability for detection of mycotoxins.•Through electrode modification with GBN, the efficiency of mycotoxins detection sensors was significantly improved.
•Review on the fundamentals of graphene: preparation, properties and application.•The preparation procedure Chemical Vapor Deposition, Mechanical Exfoliation and Hummer’s method.•The applications ...include sensors with electrodes having graphene in its pure and nanocomposite form.•Three types of applications namely electrochemical, strain and electrical sensors are explained, based on the operating principle of the sensors.•The strength, limitations of the current graphene sensors along with their future opportunities.
This paper presents an overview of the work done on graphene in recent years. It explains the preparation techniques, the properties of graphene related to its physio-chemical structure and some key applications. Graphene, due to its outstanding electrical, mechanical and thermal properties, has been one of the most popular choices to develop the electrodes of a sensor. It has been used in different forms including nanoparticle and oxide forms. Along with the preparation and properties of graphene, the categorization of the applications has been done based on the type of sensors. Comparisons between different research studies for each type have been made to highlight their performances. The challenges faced by the current graphene-based sensors along with some of the probable solutions and their future opportunities are also briefly explained in this paper.
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•Nanorod-like CoMoO4 at MPC supports were prepared by a simple method.•CoMoO4/MPC hybrids were acted as an effective sensing platform for non-enzymatic glucose detection.•The novel ...CoMoO4/MPC hybrids will hold promise in development of electrode materials.
Glucose is a popular biosensor target due to its closely with diabetes or hypoglycemia in blood. Designing efficiency electrocatalysts for the determination of glucose is vital to develop glucose detection devices. CoMoO4, as a kind of bimetallic oxide material, exhibits unique electrochemical properties. 3D macroporous carbon (MPC) has large specific surface area and excellent electrical conductivity, providing an effective support for loading other nano-entities to form novel composite with good synergetic effects. Herein, nanorod-like CoMoO4 anchored onto MPC support was synthesized for the development of a promising electrochemical sensing platform for glucose. Attributing to the synergic effects between the good electrocatalytic performance of CoMoO4 nanorods and the extraordinary electrical conductivity of 3D layered MPC, the novel CoMoO4/MPC composites non-enzymatic sensor shows excellent electrocatalytic performance for oxidation of glucose. Under the optimum conditions, the proposed CoMoO4/MPC hybrids provided a reliable linear range of 5 × 10−7 to 1.08 × 10−4 M with a low limit of detection (0.13 μM) for the detection of glucose. Meanwhile, the CoMoO4/MPC sensing platform shows fast response time of 1.76 s, good stability and selectivity for detecting glucose. Moreover, this non-enzymatic sensor also has been successfully applied to measure glucose level in human blood samples. Therefore, the developed sensor holds a new promise for the construction of facile and sensitive non-enzymatic glucose analytical platform.
•Graphene (GR)-based electrochemical sensors and biosensors are reviewed in detail.•We describe the advantages and disadvantages of GR- based sensing technologies.•We compared all the sensing systems ...in terms of their precision, reproducibilities, regeneration capacity, stabilities, and specificities.•More than 150 studies that have used GR are discussed.
Graphene (GR), the thinnest and the lightest sp2 carbon nanomaterial, has exhibited extraordinary properties in terms of fast electron mobility, high current density, high mechanical strength, excellent thermal conductivity, and ultra-larger surface area. These characteristics make GR an ideal nanomaterial for nanoelectronics, nanodevices, and nanocomposites. GR-based biosensors, thus, have attracted great attention toward providing a novel sensor platform for analyzing the target biomolecules with high sensitivity and selectivity. Moreover, GR has been used in chemical sensors because of its excellent electrochemical properties. Using GR and GR derivative-modified electrodes, enzyme and DNA biosensors, immunosensors, and chemical sensors have been developed. In this review, the methods of immobilization involved in developing biosensors and chemical sensors have been summarized in Tables. Moreover, the linear ranges, limits of detection (LODs), reproducibilities, and reusabilities of these reported biosensors and chemical sensors are compared in detail. Future prospects in this rapidly developing field are also discussed.
