Graphene oxide@Ce-doped TiO2 nanoparticles as electrocatalyst materials for voltammetric detection of hazardous methyl parathion

A review of smart electrochemical devices for pesticide detection in agricultural food and runoff contaminants

In the evolving field of food and agriculture, pesticide utilization is inevitable for food production and poses an increasing threat to the ecosystem and human health. This review systematically investigates and provides a comprehensive overview of recent developments in smart electrochemical devices for detecting pesticides in agricultural food and runoff contaminants. The focus encompasses recent progress in lab-scale and portable electrochemical sensors, highlighting their significance in agricultural pesticide monitoring. This review compares these sensors comprehensively and provides a scientific guide for future sensor development for infield agricultural pesticide monitoring and food safety. Smart devices address challenges related to power consumption, low cost, wearability, and portability, contributing to the advancement of agricultural sustainability. By elucidating the intricate details of these smart devices, this review offers a comprehensive discussion and roadmap for future research aimed at cost-effective, flexible, and smart handy devices, including novel electrocatalysts, to foster the development of next-generation agricultural sensor technology, opportunity and future direction for food security.

Surface-Enhanced Raman Spectroscopy and Electrochemistry: The Ultimate Chemical Sensing and Manipulation Combination

One of the lessons we learned from the COVID-19 pandemic is that the need for ultrasensitive detection systems is now more critical than ever. While sensors' sensitivity, portability, selectivity, and low cost are crucial, new ways to couple synergistic methods enable the highest performance levels. This review article critically discusses the synergetic combinations of optical and electrochemical methods. We also discuss three key application fields-energy, biomedicine, and environment. Finally, we selected the most promising approaches and examples, the open challenges in sensing, and ways to overcome them. We expect this work to set a clear reference for developing and understanding strategies, pros and cons of different combinations of electrochemical and optical sensors integrated into a single device.

ZnO-rGO-based electrochemical biosensor for the detection of organophosphorus pesticides

The accurate determination of organophosphorus pesticide residues is of great importance for human disease monitoring and environmental safety. Numerous detection methods exist, among which sensitive monitoring of organophosphorus compounds using electrochemical sensors has gradually become a research hotspot. This paper used acetylcholinesterase (AChE) as an indicator anchored on a zinc oxide-reduced graphene oxide (ZnO-rGO) composite rich in active sites, in which green non-toxic zinc oxide (ZnO) nanomaterials were uniformly distributed on the reduced graphene for rapid detection of organophosphorus. The effects of different ratios of ZnO to reduced graphene on the performance of ZnO-rGO nanocomposites were investigated. The AChE/ZnO-rGO biosensor detects organophosphorus by electrochemical inhibition of acetylcholinesterase in the presence of organophosphorus. The developed electrochemical biosensor has high selectivity and good linearity, and the ZnO-rGO nanocomposite as a matrix for immobilization of acetylcholinesterase and detection of organophosphorus has the potential for highly sensitive pesticide detection.

Experimental and theoretical study of improved mesoporous titanium dioxide perovskite solar cell: The impact of modification with graphene oxide

The present study serves experimental and theoretical analyses in developing a hybrid advanced structure as a photolysis, which is based on electrospun Graphene Oxide-titanium dioxide (GO-TiO2) nanofibers as an electron transfer material (ETMs) functionalized for perovskite solar cell (PVSCs) with GO. The prepared ETMs were utilized for the synthesis of mixed-cation (FAPbI3)0.8(MAPbBr3)0.2. The effect of GO on TiO2 and their chemical structure, electronic and morphological characteristic were investigated and discussed. The elaborated device, namely ITO/Bl-TiO2/3 wt% GO-TiO2/(FAPbI3)0.8(MAPbBr3)0.2/spiro-MeTAD/Pt, displayed 20.14% disposition and conversion solar energy with fill factor (FF) of 1.176%, short circuit current density (Jsc) of 20.56 mA/cm2 and open circuit voltage (VOC) 0.912 V. The obtained efficiency is higher than titanium oxide (18.42%) and other prepared GO-TiO2 composite nanofibers based ETMs. The developed materials and device would facilitate elaboration of advanced functional materials and devices for energy storage applications.

Label-Free Biochemical Sensing Using Processed Optical Fiber Interferometry: A Review

Over the last 20 years, optical fiber-based devices have been exploited extensively in the field of biochemical sensing, with applications in many specific areas such as the food processing industry, environmental monitoring, health diagnosis, bioengineering, disease diagnosis, and the drug industry due to their compact, label-free, and highly sensitive detection. The selective and accurate detection of biochemicals is an essential part of biosensing devices, which is to be done through effective functionalization of highly specific recognition agents, such as enzymes, DNA, receptors, etc., over the transducing surface. Among many optical fiber-based sensing technologies, optical fiber interferometry-based biosensors are one of the broadly used methods with the advantages of biocompatibility, compact size, high sensitivity, high-resolution sensing, lower detection limits, operating wavelength tunability, etc. This Review provides a comprehensive review of the fundamentals as well as the current advances in developing optical fiber interferometry-based biochemical sensors. In the beginning, a generic biosensor and its several components are introduced, followed by the fundamentals and state-of-art technology behind developing a variety of interferometry-based fiber optic sensors. These include the Mach-Zehnder interferometer, the Michelson interferometer, the Fabry-Perot interferometer, the Sagnac interferometer, and biolayer interferometry (BLI). Further, several technical reports are comprehensively reviewed and compared in a tabulated form for better comparison along with their advantages and disadvantages. Further, the limitations and possible solutions for these sensors are discussed to transform these in-lab devices into commercial industry applications. At the end, in conclusion, comments on the prospects of field development toward the commercialization of sensor technology are also provided. The Review targets a broad range of audiences including beginners and also motivates the experts helping to solve the real issues for developing an industry-oriented sensing device.

Recent advances in electrochemical-based sensors amplified with carbon-based nanomaterials (CNMs) for sensing pharmaceutical and food pollutants

Foodborne-related infections due to additives and pollutants pose a considerable task for food processing enterprises. Therefore, the competent, cost-effective, and quick investigation of nutrition additives and contaminants is essential to reduce the threat of public fitness problems. The electrochemical sensor (ECS) shows facile and potent analytical approaches desirable for food protection and quality inspection over traditional methods. The consequence of a broad display of nanomaterials has paved the path for their relevance in designing high-performance ECSs appliances for medical diagnostics and conditions and food protection. This review article has discussed the importance of electrochemical-based sensors amplified with carbon-based nanomaterials (CNMs). Initially, we have demonstrated the types of pharmaceutical and food/agriculture pollutants (such as pesticides, heavy metals, antibiotics and other medical drugs) present in water. Subsequently, we have compiled the information on electrochemical techniques (such as voltammetric and electrochemical impedance spectroscopy) and their crucial parameters for detecting pollutants. Further, the applications of CNMs for sensing pharmaceutical and food pollutants have been demonstrated in detail. Finally, the topic has been concluded with existing challenges and future prospects.

AuNPs and graphdiyne nanocomposite as robust electrocatalyst for methyl parathion detection in real samples

The present work describes a simple and rapid synthesis method of gold nanoparticles and graphdiyne (AuNPs@GDY) nanocomposites including porous structure. Moreover, the synthesized AuNPs@GDY material was decorated on the glassy carbon electrode (GCE) with a drop coating method to construct a non-enzymatic electrochemical pesticides sensor. The micro-morphology and elemental composition of the materials were characterized by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The electrocatalysis and conductivity of the material were studied with cyclic voltammetry (CV) and impedance method, respectively. The properties of the sensor were investigated by CV and differential pulse voltammetry (DPV). The results showed that AuNPs@GDY exhibited excellent electrocatalytic ability for methyl parathion in a wide linear range (from 0.25 ng/mL to 24.43 μg/mL) and low limit of detection value (6.2 pg/mL). Furthermore, the DPV method used in this paper was accurate and sensitive, and could be used for routine quality control of methyl parathion in kiwi fruit and tomato samples.

New analytical strategies Amplified with 2D carbon nanomaterials for electrochemical sensing of food pollutants in water and soils sources

Pharmaceutical and food pollutants have threatened global health. Pharmacotherapy has left a positive impression in the field of health and life of people and animals. However, the many unresolved problems brought along with residues of pharmaceuticals in the environmental and food. Consumption of the world's freshwater resources, toxic chemicals, air pollution, plastic waste directly affects water and soil resources. Pesticides have a wide role in pollutants. Therefore, the determination of pesticides is significant to eliminate their negative effects on living things. Nowadays, there are many analytical methods available. However, new analysis methods are still being researched due to certain limitations of traditional methods. Electrochemical sensors have drawn attention because of their superior properties, such as short analysis time, affordability, high sensitivity, and selectivity. The development of new analytical strategies for assessing risks from pharmaceutical to food pollutants in water and soil sources is important for the measurement of different pollutants. Moreover, the 2D-carbon nanomaterials used in the development of electrochemical sensors are widely utilized to enlarge the surface area, increase porosity, and make easy immobilization. Graphene (graphene derivations) and carbon nanotubes integrated nanosensors are widely used for the determination of pesticides. 2D-carbon nanomaterials can be tailored according to the purpose of the study. The characterization and synthesis methods of 2D-carbon nanomaterials are widely explained. Furthermore, enzyme nanobiosensors, especially Acetylcholinesterase (AChE), are widely used to determine pesticides. The three main topics are focused on in this review: 2D-carbon nanomaterials, pesticides that threaten life, and the application of 2D-carbon nanomaterials-based electrochemical sensors. The various developed 2D-carbon nanomaterials-based electrochemical sensors were applied in pharmaceutical forms, fruits, tap/lake water, beverages, and soils sources. This work aims to indicate the recently published paper related to pesticide analysis and highlight the importance of 2D-nanomaterials on sensors.

Recent developments on graphene and its derivatives based electrochemical sensors for determinations of food contaminants

The sensing of food contaminants is essential to prevent their adverse health effects on the consumers. Electrochemical sensors are promising in the determination of electroactive analytes including food pollutants, biomolecules etc. Graphene nanomaterials offer many benefits as electrode material in a sensing device. To further improve the analytical performance, doped graphene or derivatives of graphene such as reduced graphene oxide and their nanocomposites were explored as electrode materials. Herein, the advancements in graphene and its derivatives-based electrochemical sensors for analysis of food pollutants were summarized. Determinations of both organic (food colourants, pesticides, drugs, etc.) and inorganic pollutants (metal cations and anions) were considered. The influencing factors including nature of electrode materials and food pollutants, pH, electroactive surface area etc., on the sensing performances of modified electrodes were highlighted. The results of pollutant detection in food samples by the graphene-based electrode have also been outlined. Lastly, conclusions and current challenges in effective real sample detection were presented.

A Portable Molecularly Imprinted Sensor for On-Site and Wireless Environmental Bisphenol A Monitoring

The detection of pollutant traces in the public and environmental waters is essential for safety of the population. Bisphenol A (BPA) is a toxic chemical widely used for the production of food storage containers by plastic industries to increase the storage ability. However, the insertion of BPA in water medium leads to serious health risks. Therefore, the development of low-cost, practical, sensitive, and selective devices to monitor BPA levels on-site in the environment is highly needed. Herein, for the first time, we present a homemade portable potentiostat device integrated to a laser-scribed graphene (LSG) sensor for BPA detection as a practical environmental pollutant monitoring tool. Recently, there has been an increasing need regarding the development of graphene-based electrochemical transducers (e.g., electrodes) to obtain efficient biosensing platforms. LSG platform is combined with molecularly imprinted polymer (MIP) matrix. LSG electrodes were modified with gold nanostructures and PEDOT polymer electrodeposition to create a specific MIP biomimetic receptor for ultrasensitive BPA detection. The sensing device has a Bluetooth connection, wirelessly connected to a smartphone providing high sensitivity and sensitivity (LOD: 3.97 nM in a linear range of .01–10 µM) toward BPA. Two commercial bottled water samples, tap water, commercial milk, and baby formula samples have been used to validate the reliability of the portable sensor device.

Lanthanide type of cerium sulfide embedded carbon nitride composite modified electrode for potential electrochemical detection of sulfaguanidine

Environmental sustainability is threatened by the widespread exploitation and unfettered release of chemical pollutants that require immediate detection and eradication. An instantaneous quantification technique is essential to understand the physiological roles of the antibacterial drug sulfaguanidine (SGN) in biological systems. The present work features the green and environmentally benign synthesis of rare earth metal sulfide nanorods incorporated carbon nitrides sheets (Ce₂S₃@CNS) by deep eutectic solvent-based fabrication with remarkable electrochemical properties. The morphological and structural analyses of the prepared electrocatalyst were characterized using various techniques including SEM, XRD, XPS, and EIS. The heterojunction of regimented structures bids synergistic quantum confinement effects and refines charge carriers endorsing enormous active sites. Furthermore, the obtained Ce₂S₃@CNS/GCE possess an exceedingly lower limit of detection (0.0053 μM) and high sensitivity of 8.685 μA·μM^-1·cm^-2 with superior electrocatalytic action and virtuous stability for the detection of SGN. This modified electrode could afford linearity in the range 0.01-1131.5 μM measured at 0.95 V (vs. Ag/AgCl) correlated to the concentration of SGN. Examining the real samples with this advanced electrocatalyst would support its hands-on applications in everyday life. Development of such innovative architectures with fewer energy necessities and nominal by-products scripts the superiority in characteristic synthetic methodology following the guidelines of green chemistry.

Nanocomposite based on graphene and intercalated covalent organic frameworks with hydrosulphonyl groups for electrochemical determination of heavy metal ions

An electrochemical sensor constructed by intercalated composites was developed for determination of heavy metal ions. The intercalated composites were composed of hydrosulphonyl functional covalent organic frameworks (COF-SH) and graphene (G). The presence of numerous adsorption sites, such as 18 sulfur atoms and 30 nitrogen atoms per big circle of COFs on COF-SH, was beneficial for the accumulation of heavy metals, while the graphene enhanced the electrical conductivity. The obtained sensor under the optimal conditions successfully detected the presence of heavy metal ions in coastal water samples at concentrations ranging from 1 to 1000 μg L^-1. The detection limits of Cd (II), Pb (II), Cu (II), and Hg (II) were 0.3, 0.2, 0.2, and 1.1 μg L^-1, respectively. Furthermore, the sensor still exhibited good stability after multiple uses less than 5%. When it is used in the analysis of actual samples, the recovery of standard addition is higher than 95%. In sum, the combination of hydrosulphonyl functional COFs with graphene looks very promising for the assembly of sensors with high sensitivity toward the determination of heavy metal ions for coastal environmental monitoring.