Electrochemical (Bio)Sensors as Promising Analytical Tools in the Analysis of Soils, Plants and Environmental Monitoring

Progress, challenges, and opportunities of two-dimensional layered materials based electrochemical sensors and biosensors

There is a huge demand for fast, reliable and low-cost analytical systems for the detection and quantification of proteins with relevance in medicine, environmental pollutant monitoring, food safety, detection of foodborne pathogens and bioterrorism. Indeed, the development of biosensors fulfilling the requirements of adequate sensitivity and selectivity as well as convenience of use and cost is one of the grand scientific, engineering, and educational challenges of the 21st century. In this context, electrochemical immunosensors are considered particularly attractive analytical tools as a consequence of their inherent high sensitivity, simplicity of the operational procedure, easy availability and affordable cost of the required equipment together with possibility of miniaturization and suitability for in-field applications. Electrochemical immunosensors seek to exploit the great potentiality of immunoreactions in conjunction with electroanalytical techniques in a broad context facing a wide variety of analytical problems in medicine, biomedical research, drug discovery, environment, food, process industries, security and defense. The main goal is to provide a selective and fast response to the presence of a specific compound in a complex mixture of components, without perturbing the system. Interestingly, immunosensing using electroanalytical techniques is playing a more and more important role in protein analysis. Moreover, the growing research in advanced nanomaterials has impressively impacted also this field, by providing a great variety of novel, versatile and rationally designed nanostructured supports for transduction, signal generation and amplification. In parallel with these major advances in nanotechnology, the wide variety of immunoreagents available (commercial or produced by genetic recombination on demand conjugated with a variety of tags according to the required needs) and the versatility of design and modification offered by electrochemical substrates have also played major roles in the outstanding capabilities demonstrated by these electrochemical biosensors. The plethora of sophisticated approaches developed has exceeded even the experts' expectations in terms of functionality and resiliency. Due to the high demand of the world market and human interest for having devices able to provide the concentration of species in different complex samples, in a simple and fast way, a hard competition on this field has occurred among the researchers in recent years. In addition, the excellent and solid academic and practical multidisciplinary formation in sensors biotechnology, surface chemistry, advanced nanomaterials, and electrochemical transduction and characterization methods for immunodetection of these researchers amply justifies the unimaginable progress reached in such a short time and the fact that people working in this area do not dare to put limits on this field. The present Special Issue, which compiles 9 full papers, 2 short communications and 8 dedicated review articles, was authored by leading experts and pioneers in electrochemical immunosensors. These articles shed useful insights into the latest advances, current trends and future prospects in this exciting field. In particular, the selected contributions described the development of electrochemical immunosensing scaffolds to detect pollutants (polybrominated diphenyllethers, mycotoxins), clinical biomarkers (interleukin-8, estrogen and progesterone receptors), drugs (brombuterol), rotavirus and microbes and revise nicely the use of screen-printed electrodes, common and uncommon nanostructures, polymeric films, 3D-printing microfluidics and proximity ligation assays in the development of electrochemical immunosensors. Compiled contributions give also expert and updated overviews of this topic in multiplexed approaches, control of electron transfer, advantages compared with aptasensors and latest applications in real clinical practice. Therefore, one can envision further exciting applications of electrochemical immune-platforms for making ‘house-calls' in biomedical diagnostics and cancer theranostics, as inspectors for environmental monitoring, even in harsh working conditions, as well as alarm devices for food safety. The unique combination and integration of nanotechnology, micro and nanofluidics with immunoreactions and electrochemical analytical methodologies is expected to produce major advances in this area and open up new opportunities not only from the scientific point of view but even from a market perspective preparing point-of-care devices and in-situ alarm systems. Given the rapid development, interest and progress made in this field, the examples compiled in this Special Issue are just a small sample of those expected to come in this amazing field which future growth and success will rely on the abilities of the researchers to continue innovating and collaborating to address the existing challenges and opportunities. In the near future, advances in fundamental knowledge of new nanomaterials along with a focus on practical applications in real-world systems will drive electrochemical immunosensors to breakthroughs in many fields of social and economical relevance. As a logical consequence of the incessant flow of impressive ideas and innovations it looks like this field has the horsepower to keep on advancing for the foreseeable future.

The rapid progress of nanotechnology, especially in green analytical chemistry, has opened up new possibilities for novel applications in a wide range of fields, especially environmental science. This chapter focuses on advancing green sensors within the realm of electrochemical (bio)sensors, with a dedicated emphasis on environmentally sustainable practices. The investigation explores the development of eco-friendly sensing technologies, utilizing green materials and methodologies for the fabrication of electrochemical sensors. Special attention is given to the incorporation of sustainable nanoparticle designs, highlighting their application in enhancing the sensitivity and selectivity of (bio)sensors. The research explores the application of green chemistry concepts to the synthesis of sensing components with the aim of minimizing their environmental effect. Furthermore, the research evaluates the integration of green technologies, such as biofuel cells, in electrochemical sensors for enhanced energy efficiency and biocompatibility. The use of renewable resources and the development of biodegradable sensor components align with the overarching goal of minimizing the environmental footprint. This exploration extends to the application of electrochemical (bio)sensors in environmental monitoring, emphasizing their role in detecting pollutants and contributing to sustainable resource management. The study concludes with a discussion on the potential of green sensors to shape the future of electrochemical sensing technologies, fostering innovation in an ecologically responsible and technologically advanced manner.

Taking advantage of exceptional attributes, such as being easy-to-operate, economical, sensitive, portable, and simple-to-construct, in recent decades, considerable attention has been devoted to the integration of recognition elements with electronic elements to develop electrochemical sensors and biosensors.Various electrochemical devices, such as amperometric sensors, electrochemical impedance sensors, and electrochemical luminescence sensors as well as photoelectrochemical sensors, provide wide applications in the detection of chemical and biological targets in terms of electrochemical change of electrode interfaces. With remarkable achievements in nanotechnology and nanoscience, nanomaterial-based electrochemical signal amplifications have great potential of improving both sensitivity and selectivity for electrochemical sensors and biosensors. First of all, it is well-known that the electrode materials play a critical role in the construction of high-performance electrochemical sensing platforms for detecting target molecules through various analytical principles. Furthermore, in addition to electrode materials, functional nanomaterials can not only produce a synergic effect among catalytic activity, conductivity, and biocompatibility to accelerate the signal transduction but also amplify biorecognition events with specifically designed signal tags, leading to highly sensitive biosensing. Significantly, extensive research on the construction of functional electrode materials, coupled with numerous electrochemical methods, is advancing the wide application of electrochemical devices. For example, Walcarius et al. highlighted the recent advances of nano-objects and nanoengineered and/or nanostructured materials for the rational design of biofunctionalized electrodes and related (bio)sensing systems.1 The attractiveness of such nanomaterials relies on their ability to act as effective immobilization matrices and their intrinsic and unique features as described above. These features combined with the functioning of biomolecules contribute to the improvement of bioelectrode performance in terms of sensitivity and specificity. Our group recently presented a general overview of nanomaterial-enhanced paper-based biosensors including lateral-flow test-strip and paper microfluidic devices.2 With different kinds of nanoparticles (NPs), paper-based biosensor devices have shown a great potential in the enhancement of sensitivity and specificity of disease diagnosis in developing countries. This Review focuses on recent advances in electrochemical sensors and biosensors based on nanomaterials and nanostructures during 2013 to 2014. The aim of this effort is to provide the reader with a clear and concise view of new advances in areas ranging from electrode engineering, strategies for electrochemical signal amplification, and novel electroanalytical techniques used in the miniaturization and integration of the sensors. Moreover, the authors have attempted to highlight areas of the latest and significant development of enhanced electrochemical nanosensors and nanobiosensors that inspire broader interests across various disciplines. Electrochemical sensors for small molecules, enzyme-based biosensors, genosensors, immunosensors, and cytosensors are reviewed herein (Figure ​(Figure1).1). Such novel advances are important for the development of electrochemical sensors that open up new avenues and methods for future research. We recommend readers interested in the general principles of electrochemical sensors and electrochemical methods to refer to other excellent literature for a broad scope in this area.3,4 However, due to the explosion of publications in this active field, we do not claim that this Review includes all of the published works in the past two years and we apologize to the authors of excellent work, which is unintentionally left out. Figure 1 Schematic illustration of electrochemical sensors and biosensors based on nanomaterials and nanostructures, in which electrochemical sensors for small molecular, enzyme-based biosensors, genosensors, immunosensors, and cytosensors are demonstrated.

Electrochemical Sensor Analysis

Heavy metals detection at chemometrics-powered electrochemical (bio)sensors

Carbendazim, a fungicide widely used in agriculture, has been classified as a hazardous chemical by the World Health Organization due to its environmental persistence. It is prohibited in several countries; therefore, detecting it in food and environmental samples is highly necessary. A reliable, rapid, and low-cost method uses electrochemical sensors and biosensors, especially those modified with carbon-based materials with good analytical performance. In this review, we summarize the use of carbon-based electrochemical (bio)sensors for detecting carbendazim in environmental and food matrixes, with a particular interest in the role of carbon materials. Focus on publications between 2018 and 2023 that have been describing the use of carbon nanotubes, carbon nitride, graphene, and its derivatives, and carbon-based materials as modifiers, emphasizing the analytical performance obtained, such as linear range, detection limit, selectivity, and the matrix where the detection was applied.

Recent progress on electrochemical (bio)sensors based on aptamer-molecularly imprinted polymer dual recognition

Electrochemical sensors, sensor arrays and biosensors, alongside chemometric instruments, have progressed remarkably of late, being used on a wide scale in the qualitative and quantitative evaluation of olive oil. Olive oil is a natural product of significant importance, since it is a rich source of bioactive compounds with nutritional and therapeutic properties, and its quality is important both for consumers and for distributors. This review aims at analysing the progress reported in the literature regarding the use of devices based on electrochemical (bio)sensors to evaluate the bioactive compounds in olive oil. The main advantages and limitations of these approaches on construction technique, analysed compounds, calculus models, as well as results obtained, are discussed in view of estimation of future progress related to achieving a portable, practical and rapid miniature device for analysing the quality of virgin olive oil (VOO) at different stages in the manufacturing process.

Magnetic nanomaterials based electrochemical (bio)sensors for food analysis

Modern bioelectrochemistry: Bioelectrochemistry is a diverse field, with impact on many areas in chemistry, from energy storage to understanding biological processes at a fundamental level. Given the rapid developments in this field during recent years, this Special Collection aims to highlight the latest developments in all aspects of bioelectrochemistry.

Recent trends in layered double hydroxides based electrochemical and optical (bio)sensors for screening of emerging pharmaceutical compounds

Bioapplications of Electrochemical Sensors and Biosensors.

Covalent organic frameworks (COFs) are defined as crystalline organic polymers with programmable topological architectures using properly predesigned building blocks precursors. Since the development of the first COF in 2005, many works are emerging using this kind of material for different applications, such as the development of electrochemical sensors and biosensors. COF shows superb characteristics, such as tuneable pore size and structure, permanent porosity, high surface area, thermal stability, and low density. Apart from these special properties, COF’s electrochemical behaviour can be modulated using electroactive building blocks. Furthermore, the great variety of functional groups that can be inserted in their structures makes them interesting materials to be conjugated with biological recognition elements, such as antibodies, enzymes, DNA probe, aptamer, etc. Moreover, the possibility of linking them with other special nanomaterials opens a wide range of possibilities to develop new electrochemical sensors and biosensors.

Chapter 10 - Electroanalytical techniques in biosciences: conductometry, coulometry, voltammetry, and electrochemical sensors