scholarly journals Electrochemical Biosensors for Tracing Cyanotoxins in Food and Environmental Matrices

Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 315
Author(s):  
Antonella Miglione ◽  
Maria Napoletano ◽  
Stefano Cinti

The adoption of electrochemical principles to realize on-field analytical tools for detecting pollutants represents a great possibility for food safety and environmental applications. With respect to the existing transduction mechanisms, i.e., colorimetric, fluorescence, piezoelectric etc., electrochemical mechanisms offer the tremendous advantage of being easily miniaturized, connected with low cost (commercially available) readers and unaffected by the color/turbidity of real matrices. In particular, their versatility represents a powerful approach for detecting traces of emerging pollutants such as cyanotoxins. The combination of electrochemical platforms with nanomaterials, synthetic receptors and microfabrication makes electroanalysis a strong starting point towards decentralized monitoring of toxins in diverse matrices. This review gives an overview of the electrochemical biosensors that have been developed to detect four common cyanotoxins, namely microcystin-LR, anatoxin-a, saxitoxin and cylindrospermopsin. The manuscript provides the readers a quick guide to understand the main electrochemical platforms that have been realized so far, and the presence of a comprehensive table provides a perspective at a glance.

2015 ◽  
Vol 69 (1) ◽  
Author(s):  
Jana Šefčovičová ◽  
Jan Tkac

AbstractMicrobial cell biosensors, where cells are in direct connection with a transducer enabling quantitative and qualitative detection of an analyte, are very promising analytical tools applied mainly for assays in the environmental field, food industry or biomedicine. Microbial cell biosensors are an excellent alternative to conventional analytical methods due to their specificity, rapid detection and low cost of analysis. Nowadays, nanomaterials are often used in the construction of biosensors to improve their sensitivity and stability. In this review, the combination of microbial and other individual cells with different nanomaterials (carbon nanotubes, graphene, gold nanoparticles, etc.) for the construction of biosensors is described and their applications are provided as well.


Author(s):  
M. I. Rodriguez-Laiton ◽  
H. A. León-Vega ◽  
E. Upegui

Abstract. The following article describes the implementation of a methodology for the structural reconstruction of the Heroes monument and the statue on the north side of Simon Bolivar Ecuestre located between the intersection of the north highway and 80th Street in Bogota (Colombia) from the acquisition of SFM photogrammetry methods and images, using low-cost sensors for this process and making use of drones from the obtaining of frames of a video to for areas with lower altimetric reach, and thereby creating an analysis in their accuracy, sizing and quality within the framework of appropriation and documentation of the cultural assets in the public space of the city Bogotá taking this data as a starting point for future developments in the process of 3D reconstructions Colombia.


Foods ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 141 ◽  
Author(s):  
Geetesh Mishra ◽  
Abbas Barfidokht ◽  
Farshad Tehrani ◽  
Rupesh Mishra

Rapid and precise analytical tools are essential for monitoring food safety and screening of any undesirable contaminants, allergens, or pathogens, which may cause significant health risks upon consumption. Substantial developments in analytical techniques have empowered the analyses and quantitation of these contaminants. However, conventional techniques are limited by delayed analysis times, expensive and laborious sample preparation, and the necessity for highly-trained workers. Therefore, prompt advances in electrochemical biosensors have supported significant gains in quantitative detection and screening of food contaminants and showed incredible potential as a means of defying such limitations. Apart from indicating high specificity towards the target analytes, these biosensors have also addressed the challenge of food industry by providing high analytical accuracy within complex food matrices. Here, we discuss some of the recent advances in this area and analyze the role and contributions made by electrochemical biosensors in the food industry. This article also reviews the key challenges we believe biosensors need to overcome to become the industry standard.


2021 ◽  
Author(s):  
Luca Mauri ◽  
Eugenio Straffelini ◽  
Sara Cucchiaro ◽  
Paolo Tarolli

<p>The presence of roads is closely linked with the activation of land degradative phenomena such as landslides. Factors such as ineffective road management and design, local rainfall regimes and specific geomorphological elements actively influence landslides occurrence. In this context, recent developments in digital photogrammetry (e.g. Structure from Motion; SfM) paired with Remotely Piloted Aircraft Systems (RPAS) increase our possibilities to realize low-cost and recurrent topographic surveys. This allows the realization of multi-temporal (hereafter 4D) and high-resolution Digital Elevation Models (DEMs), fundamental to analyse geomorphological features and quantify processes at the fine spatial and temporal resolutions at which they occur. In this research is presented a 4D comparison of geomorphological indicators describing a landslide-prone agricultural system, so as to detect the noticed high-steep slope failures. The possibility to analyse the evolution of landslide geomorphic features in steep agricultural systems through high-resolution and 4D comparison of such indicators is still a challenge to be investigated. In this research, we considered a case study located in the central Italian Alps, where two shallow landslides (L1, L2) were activated below a rural road within a terraced vineyard. The dynamics of the landslides were monitored through the comparison of repeated DEMs (DEM of Difference, i.e. DoD), that reported erosion values of above 20 m<sup>3</sup> and 10 m<sup>3</sup> for the two landslides zones and deposition values of more than 15 m<sup>3</sup> and 9 m<sup>3</sup> respectively. The elaboration of Relative Path Impact Index (RPII) highlighted the role played by the road in the alteration of surface water flow directions. Altered water flows were expressed by values between 2σ and 4σ of RPII close to the collapsed surfaces. The increasing of profile curvature and roughness index described landslides evolution over time. Finally, the multi-temporal comparison of features extraction underlined the geomorphological changes affecting the study area. The computation of the quality index underlined the accuracy of features extraction. This index is expressed in a range between 0 (low accuracy) and 1 (high accuracy) and resulted equal to 0.22 m, regarding the landslide observed during the first RPAS survey (L1-pre); 0.63 m, concerning the same landslide detected during the second RPAS survey (L1-post); 0.69 m for L2. Results prove the usefulness of high-resolution and 4D RPAS-based SfM surveys for the investigation of landslides triggering due to the presence of roads at hillslope scale in agricultural systems. This work could be a useful starting point for further studies of landslide-susceptible zones at a wider scale, to preserve the quality and the productivity of affected agricultural areas.</p>


2001 ◽  
Author(s):  
Kilian Bizer ◽  
Martin Führ

The starting point of the research project was the hypothesis that the "principle of proportionality", which is fundamental to law, is related to the "economic principle". The resulting methodological similarities were intended to enable a cross-disciplinary bridge to be built, which would allow the findings of economic analysis to be made fruitful for legal issues. This was practically tested in three study areas in order to be able to better classify the performance of the analytical tools. The foundations for interdisciplinary bridge building are found in the rational-choice paradigm. In both disciplines, this paradigm calls for an examination of the relationship between the purpose-means-relations: among the design options under consideration, the one must be selected that is expected to be as (freedom- or resource-) sparing as possible, in other words, the most "waste-free" solution to the control problem.The results of the economic analysis can thus be "translated" in such a way that, within the framework of "necessity", they support the search for control instruments that are equivalent to the objective but less disruptive. supports. The core of the positive economic analysis is the motivational situation of those actors whose behavior is to be influenced by a changed legal framework. In this context, the classical behavioral model of economics proved to be too limited. It therefore had to be developed further in line with the findings of research in institutional economics into homo oeconomicus institutionalis. This behavioral model takes into account not only the consequentialist, strictly situational utility orientation of the model person, but also other factors influencing behavior, including above all those that are institutionally mediated. If one takes the motivational situation of the actors as the starting point for policy-advising design recommendations, it becomes apparent that an understanding of governance dominated by imperative behavioral specifications leads to less favorable results, both in terms of the degree to which goals are achieved and in terms of the freedom-impairing effects, than a mixed-instrument approach oriented toward the model of "responsive regulation." According to this model, the law can no longer simply assume that those subject to the law will "obediently" execute the legal commands. It must ask itself what other factors determine behavior and under what boundary conditions changes can be expected in the direction of the desired behavior. For this reason, too, it must engage with the cognitive program of the behavioral sciences. This linkage opens up new perspectives for interdisciplinary research on the consequences of laws.


Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2879 ◽  
Author(s):  
Lucas Ferreira Ribeiro ◽  
Vanesa Amarelle ◽  
Luana de Fátima Alves ◽  
Guilherme Marcelino Viana de Siqueira ◽  
Gabriel Lencioni Lovate ◽  
...  

Protein engineering emerged as a powerful approach to generate more robust and efficient biocatalysts for bio-based economy applications, an alternative to ecologically toxic chemistries that rely on petroleum. On the quest for environmentally friendly technologies, sustainable and low-cost resources such as lignocellulosic plant-derived biomass are being used for the production of biofuels and fine chemicals. Since most of the enzymes used in the biorefinery industry act in suboptimal conditions, modification of their catalytic properties through protein rational design and in vitro evolution techniques allows the improvement of enzymatic parameters such as specificity, activity, efficiency, secretability, and stability, leading to better yields in the production lines. This review focuses on the current application of protein engineering techniques for improving the catalytic performance of enzymes used to break down lignocellulosic polymers. We discuss the use of both classical and modern methods reported in the literature in the last five years that allowed the boosting of biocatalysts for biomass degradation.


Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5461 ◽  
Author(s):  
Alain Küng ◽  
Benjamin A. Bircher ◽  
Felix Meli

Accurate traceable measurement systems often use laser interferometers for position measurements in one or more dimensions. Since interferometers provide only incremental information, they are often combined with index sensors to provide a stable reference starting point. Straightness measurements are important for machine axis correction and for systems having several degrees of freedom. In this paper, we investigate the accuracy of an optical two-dimensional (2D) index sensor, which can also be used in a straightness measurement system, based on a fiber-coupled, collimated laser beam pointing onto an image sensor. Additionally, the sensor can directly determine a 2D position over a range of a few millimeters. The device is based on a simple and low-cost complementary metal–oxide–semiconductor (CMOS) image sensor chip and provides sub-micrometer accuracy. The system is an interesting alternative to standard techniques and can even be implemented on machines for real-time corrections. This paper presents the developed sensor properties for various applications and introduces a novel error separation method for straightness measurements.


Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 662 ◽  
Author(s):  
Mohsen Mohammadniaei ◽  
Huynh Vu Nguyen ◽  
My Van Tieu ◽  
Min-Ho Lee

Effective cancer treatment requires early detection and monitoring the development progress in a simple and affordable manner. Point-of care (POC) screening can provide a portable and inexpensive tool for the end-users to conveniently operate test and screen their health conditions without the necessity of special skills. Electrochemical methods hold great potential for clinical analysis of variety of chemicals and substances as well as cancer biomarkers due to their low cost, high sensitivity, multiplex detection ability, and miniaturization aptitude. Advances in two-dimensional (2D) material-based electrochemical biosensors/sensors are accelerating the performance of conventional devices toward more practical approaches. Here, recent trends in the development of 2D material-based electrochemical biosensors/sensors, as the next generation of POC cancer screening tools, are summarized. Three cancer biomarker categories, including proteins, nucleic acids, and some small molecules, will be considered. Various 2D materials will be introduced and their biomedical applications and electrochemical properties will be given. The role of 2D materials in improving the performance of electrochemical sensing mechanisms as well as the pros and cons of current sensors as the prospective devices for POC screening will be emphasized. Finally, the future scopes of implementing 2D materials in electrochemical POC cancer diagnostics for the clinical translation will be discussed.


2018 ◽  
Vol 7 (4.6) ◽  
pp. 257
Author(s):  
M. Srilatha ◽  
R. Hemalatha

In small-scale industries, under extreme working conditions, personnel are frequently involved in lifting and carrying raw materials, which is hazardous at times. Robot, a machine with intelligence can perform the same task with the help of control instructions fed by computer or remote control. Technological development in the area of robotics made it possible to design robotic arm with the same degree of precision as a replacement to the human intervention. This will introduce automation in small-scale industries, which saves time, reduces human effort and expenditure in production. Further, this will be a starting point for complete automation of entire process, which can be expensive and complicated. NI LabVIEW along with NI-myRIO can provide a better solution in designing a more precise and accurate robot in a very low cost, which is affordable by small-scale industries. NI-myRIO is used to generate and acquire signals for controlling and processing. Further it has an inbuilt processor and FPGA which has many reconfigurable analogue and digital features.  


Biosensors ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 32 ◽  
Author(s):  
Beatriz Pérez-Fernández ◽  
Agustín Costa-García ◽  
Alfredo de la Escosura- Muñiz

Pesticides are among the most important contaminants in food, leading to important global health problems. While conventional techniques such as high-performance liquid chromatography (HPLC) and mass spectrometry (MS) have traditionally been utilized for the detection of such food contaminants, they are relatively expensive, time-consuming and labor intensive, limiting their use for point-of-care (POC) applications. Electrochemical (bio)sensors are emerging devices meeting such expectations, since they represent reliable, simple, cheap, portable, selective and easy to use analytical tools that can be used outside the laboratories by non-specialized personnel. Screen-printed electrodes (SPEs) stand out from the variety of transducers used in electrochemical (bio)sensing because of their small size, high integration, low cost and ability to measure in few microliters of sample. In this context, in this review article, we summarize and discuss about the use of SPEs as analytical tools in the development of (bio)sensors for pesticides of interest for food control. Finally, aspects related to the analytical performance of the developed (bio)sensors together with prospects for future improvements are discussed.


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