Despite the enormous development of instruments for analyzing a wide variety of compounds, applied in different fields such as health, environment or quality control, the demand for increasingly ...sensitive and selective techniques continues to grow. In this regard, efforts have been made to highlight more appropriate techniques. Electrochemical sensors based on molecularly imprinted polymers (MIPs) offer an interesting alternative since they allow reaching high sensitivity and selectivity and they are inexpensive and easily adaptable to miniaturization. The choice of the functional monomer in the synthesis of MIPs is based on its capacity to provide complementary interactions with the target molecules. The various excellent properties of chitosan, as a biosourced polymer, make it a promising alternative to conventional functional monomers. This review reports on the principle of the MIPs technique describing the different possible approaches in their synthesis. It aims to provide an overview of the value of using chitosan as a functional monomer by highlighting its applications in electrochemical sensors.
•Chitosan is a biosourced polymer composed of glycosamine units.•Due to its functional groups, chitosan could constitute the basis of molecularly imprinted polymers.•Twenty-four articles report MIP chitosan-based electrochemical sensors.•Many small molecules were detected with MIP chitosan-based electrochemical sensors.
Electroanalysis has obtained considerable progress over the past few years, especially in the field of electrochemical sensors. Broadly speaking, electrochemical sensors include not only conventional ...electrochemical biosensors or non‐biosensors, but also emerging electrochemiluminescence (ECL) sensors and photoelectrochemical (PEC) sensors which are both combined with optical methods. In addition, various electrochemical sensing devices have been developed for practical purposes, such as multiplexed simultaneous detection of disease‐related biomarkers and non‐invasive body fluid monitoring. For the further performance improvement of electrochemical sensors, material is crucial. Recent years, a kind of two‐dimensional (2D) nanomaterial MXene containing transition metal carbides, nitrides and carbonitrides, with unique structural, mechanical, electronic, optical, and thermal properties, have attracted a lot of attention form analytical chemists, and widely applied in electrochemical sensors. Here, we reviewed electrochemical sensors based on MXene from Nov. 2014 (when the first work about electrochemical sensor based on MXene published) to Mar. 2021, dividing them into different types as electrochemical biosensors, electrochemical non‐biosensors, electrochemiluminescence sensors, photoelectrochemical sensors and flexible sensors. We believe this review will be of help to those who want to design or develop electrochemical sensors based on MXene, hoping new inspirations could be sparked.
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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•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.
Electrochemical sensors are powerful analytical tools that, in the last few years, have attracted tremendous attention in coupling with wearable devices due to their incomparable properties, such as ...instrumental simplicity, low cost, flexibility, and miniaturization. These outstanding characteristics fit with the desired features for continuous on-body analyses. Wearable electrochemical sensors enable obtaining insights into individuals' health status through the noninvasive monitoring of clinically relevant biomarkers in different biofluids (saliva, tears, sweat, and interstitial fluids) without complex manipulation, sampling, and treatment steps. The electrochemical system can be fabricated in different substrates and transferred to the human body or coupled to common utensils to monitor (bio)chemical species or potentially hazardous compounds surrounding the users without disturbing their usual activities. In this work, we critically review the recent advances, the main technological and chemical challenges identified in wearable electrochemical sensors for forensic and clinical applications, highlighting the remarkable trends, needs, and challenges for future studies.
•Relevant wearable electrochemical sensors (WES) over the last five years are reviewed.•Main fabrication methods and strategies used in WES are presented.•Clinical and forensic applications are critically discussed.•Prospects and challenges towards real-time on-body analyses are described.•Recent advances, main technological and chemical challenges identified in WES applied for forensic sciences.
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.
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.
•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.
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.
•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.
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