Application of Carbon Nanotubes in the Extraction and Electrochemical Detection of Organophosphate Pesticides: A Review

A review of recent developments based on chemiluminescence detection systems for pesticides analysis

Chemiluminescence is one of the most coveted methods for sensitive determination of pesticides in food and environmental samples. To date, many methods have been developed for qualitative and quantitative analysis of pesticides, ranging from traditional to advanced methods. This study outlines the progress in the conventional and advanced analytical methods, coupled to a chemiluminescence detection system, that are employed for the determination of pesticides in food and environmental samples. Different analytical methods including chromatographic methods, flow-based systems, and paper-based systems are reviewed in this paper. As well, new advances in the application of nanomaterials, aptamer, and molecularly imprinted polymers are highlighted. We also address the challenges and difficulties associated with these methods. Finally, we highlight the future direction in this active field of research.

Recent uses of carbon nanotubes & gold nanoparticles in electrochemistry with application in biosensing: A review

The innovation of nanoparticles assumes a critical part of encouraging and giving open doors and conceivable outcomes to the headway of new era devices utilized as a part of biosensing. The focused on the quick and legitimate detecting of specific biomolecules using functionalized gold nanoparticles (Au NPs), and carbon nanotubes (CNTs) has turned into a noteworthy research enthusiasm for the most recent decade. Sensors created with gold nanoparticles or carbon nanotubes or in some cases by utilizing both are relied upon to change the very establishments of detecting and distinguishing various analytes. In this review, we will examine the current utilization of functionalized AuNPs and CNTs with other synthetic mixes for the creation of biosensor prompting to the location of particular analytes with low discovery cutoff and quick reaction.

Optical detection of paraoxon using single-walled carbon nanotube films with attached organophosphorus hydrolase-expressed Escherichia coli

In whole-cell based biosensors, spectrophotometry is one of the most commonly used methods for detecting organophosphates due to its simplicity and reliability. The sensor performance is directly affected by the cell immobilization method because it determines the amount of cells, the mass transfer rate, and the stability. In this study, we demonstrated that our previously-reported microbe immobilization method, a microbe-attached single-walled carbon nanotube film, can be applied to whole-cell-based organophosphate sensors. This method has many advantages over other whole-cell organophosphate sensors, including high specific activity, quick cell immobilization, and excellent stability. A device with circular electrodes was fabricated for an enlarged cell-immobilization area. Escherichia coli expressing organophosphorus hydrolase in the periplasmic space and single-walled carbon nanotubes were attached to the device by our method. Paraoxon was hydrolyzed using this device, and detected by measuring the concentration of the enzymatic reaction product, p-nitrophenol. The specific activity of our device was calculated, and was shown to be over 2.5 times that reported previously for other whole-cell organophosphate sensors. Thus, this method for generation of whole-cell-based OP biosensors might be optimal, as it overcomes many of the caveats that prevent the widespread use of other such devices.

Enzymes as useful tools for environmental purposes

In the environment enzymes may play important and different roles at least in three cases: as main agents (as isolated, cell-bound or immobilized enzymes) in charge of either the transformation and/or degradation of compounds polluting the environment and the restoration of the polluted environment; as reliable and sensitive tools to detect and measure the amount and concentration of pollutants before, during and after the restoration process; as reliable, easy and sensitive indicators of quality and health status of the environment subjected to the restoration process. To our knowledge papers or reviews integrating findings on these three functions of enzymes are missing in literature. Therefore the main scope of the present paper is to briefly encompass general and specific concepts about roles of enzymes as decontaminating agents, pollutant assaying agents and indicators of environment safety. Examples chosen among those published very recently, supporting and confirming peculiarities, features, and performance of enzymatic agents will be illustrated.