scholarly journals Recent Advances on Detection of Insecticides Using Optical Sensors

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3856
Author(s):  
Nurul Illya Muhamad Fauzi ◽  
Yap Wing Fen ◽  
Nur Alia Sheh Omar ◽  
Hazwani Suhaila Hashim
Keyword(s):  
Optical Sensors ◽  
Food Environment ◽  
High Selectivity ◽  
Limit Of Detection ◽  
Low Cost ◽  
Living Things ◽  
Repeated Use ◽  
Recognition Elements ◽  
User Friendly ◽  
Review Current

Insecticides are enormously important to industry requirements and market demands in agriculture. Despite their usefulness, these insecticides can pose a dangerous risk to the safety of food, environment and all living things through various mechanisms of action. Concern about the environmental impact of repeated use of insecticides has prompted many researchers to develop rapid, economical, uncomplicated and user-friendly analytical method for the detection of insecticides. In this regards, optical sensors are considered as favorable methods for insecticides analysis because of their special features including rapid detection time, low cost, easy to use and high selectivity and sensitivity. In this review, current progresses of incorporation between recognition elements and optical sensors for insecticide detection are discussed and evaluated well, by categorizing it based on insecticide chemical classes, including the range of detection and limit of detection. Additionally, this review aims to provide powerful insights to researchers for the future development of optical sensors in the detection of insecticides.

scholarly journals Introducing the Facility List Coder: A New Dataset/Method to Evaluate Community Food Environments

Data ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 23
Author(s):  
Ana María Arcila-Agudelo ◽  
Juan Carlos Muñoz-Mora ◽  
Andreu Farran-Codina
Keyword(s):  
Food Environment ◽  
Physical Inactivity ◽  
Low Cost ◽  
Food Environments ◽  
Standard Data ◽  
Research Questions ◽  
Access Information ◽  
User Friendly ◽  
Community Food Environment ◽  
Source Of Information

Community food environments have been shown to be important determinants to explain dietary patterns. This data descriptor describes a typical dataset obtained after applying the Facility List Coder (FLC), a new tool to asses community food environments that was validated and presented. The FLC was developed in Python 3.7 combining GIS analysis with standard data techniques. It offers a low-cost, scalable, efficient, and user-friendly way to indirectly identify community nutritional environments in any context. The FLC uses the most open access information to identify the facilities (e.g., convenience food store, bar, bakery, etc.) present around a location of interest (e.g., school, hospital, or university). As a result, researchers will have a comprehensive list of facilities around any location of interest allowing the assessment of key research questions on the influence of the community food environment on different health outcomes (e.g., obesity, physical inactivity, or diet quality). The FLC can be used either as a main source of information or to complement traditional methods such as store census and official commercial lists, among others.

scholarly journals Design & Development of Laser Etched Porous-Silicon Capacitive Chip for Rapid Sensing of Pesticide Solvents

2021 ◽  
Author(s):  
shailesh mahendralal gheewala ◽  
Chinthakunta Parmesh ◽  
Piyush N. Patel ◽  
Rasika Dhavse
Keyword(s):  
Porous Silicon ◽  
Organic Solvents ◽  
Optical Sensors ◽  
Limit Of Detection ◽  
Low Cost ◽  
Single Layer ◽  
Capacitive Sensor ◽  
Average Pore ◽  
Chip Design ◽  
Silicon Based

Abstract This work presents the development of porous silicon-based electrical sensor for the detection and quantification of organic solvents. The design of silicon chip is modeled as capacitive sensor. Different electrode configurations like coplanar top electrodes, top-bottom, coplanar bottom electrodes were analyzed in order to select optimum chip design for sensing application. The prototype chip was fabrication that used a mechanized pulse fiber laser etching process in order to develop a single-layer silicon structure with uniform porous structures. The fabricated chip was characterized using scanning electron microscopy and it shows an average pore diameter of 55.22 µm and pore depth of 98.9 µm. Organic solvents like ethanol, methanol, acetonitrile were tested and analyzed in order to investigate the performance of the proposed chip. Unlike porous silicon based optical sensors, the proposed sensor exhibited stable results up to 35 days at room temperature. The application of the proposed sensor chip is demonstrated for sensing and for the quantification of Atrazine chemical which is a pesticide solvent which is utilized in farming to control weeds. The sensitivity and the limit of detection was found to be 0.51 nF/ppm and 0.929 ppm respectively. The proposed capacitive-based porous silicon chip is suitable for time-effective and low-cost sensing and detection of organic solvents that are used in food industry.

scholarly journals Laboratory Comparison of Low-Cost Particulate Matter Sensors to Measure Transient Events of Pollution

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2219 ◽  
Author(s):  
Florentin Michel Jacques Bulot ◽  
Hugo Savill Russell ◽  
Mohsen Rezaei ◽  
Matthew Stanley Johnson ◽  
Steven James Johnston Ossont ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Optical Sensors ◽  
Limit Of Detection ◽  
Low Cost ◽  
Airborne Particulate Matter ◽  
Environmental Parameters ◽  
Additional Information ◽  
Sources Of Pollution ◽  
Premature Deaths ◽  
The Impact

Airborne particulate matter (PM) exposure has been identified as a key environmental risk factor, associated especially with diseases of the respiratory and cardiovascular system and with almost 9 million premature deaths per year. Low-cost optical sensors for PM measurement are desirable for monitoring exposure closer to the personal level and particularly suited for developing spatiotemporally dense city sensor networks. However, questions remain over the accuracy and reliability of the data they produce, particularly regarding the influence of environmental parameters such as humidity and temperature, and with varying PM sources and concentration profiles. In this study, eight units each of five different models of commercially available low-cost optical PM sensors (40 individual sensors in total) were tested under controlled laboratory conditions, against higher-grade instruments for: lower limit of detection, response time, responses to sharp pollution spikes lasting <1 min , and the impact of differing humidity and PM source. All sensors detected the spikes generated with a varied range of performances depending on the model and presenting different sensitivity mainly to sources of pollution and to size distributions with a lesser impact of humidity. The sensitivity to particle size distribution indicates that the sensors may provide additional information to PM mass concentrations. It is concluded that improved performance in field monitoring campaigns, including tracking sources of pollution, could be achieved by using a combination of some of the different models to take advantage of the additional information made available by their differential response.

scholarly journals Development of a Nonenzymatic Electrochemical Sensor for Organophosphate Pesticide Detection Using Copper (II) Oxide Nanorod Electrodes

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Phichamon Sakdarat ◽  
Jidapa Chongsuebsirikul ◽  
Chanchana Thanachayanont ◽  
Seeroong Prichanont ◽  
Porpin Pungetmongkol
Keyword(s):  
High Selectivity ◽  
Electrode Materials ◽  
Electrochemical Sensors ◽  
Limit Of Detection ◽  
Low Cost ◽  
Sodium Sulphate ◽  
Maximum Residue Limit ◽  
Pesticide Detection ◽  
Lower Complexity ◽  
Detection Unit

Inorganic electrode materials of low cost, lower complexity, and high stability have become the more preferred choice over enzyme usage in electrochemical sensors. In this work, copper oxide (CuO) nanorods (NRs) were synthesized on copper foil as electrodes through anodization and annealing processes. The synthesized electrodes were used to analyse the organophosphate pesticides (OPPs) and interference molecules by cyclic voltammetry. The CuO NR sensor was able to identify and quantify different kinds of OPPs with an elevated sensitivity of 1.269, 1.425, 1.657, and 2.833 μA/ng mL-1 for chlorpyrifos, parathion, paraoxon, and pirimiphos and explicitly separate them from interference molecules (i.e., carbaryl, paraquat, sodium nitrate, sodium sulphate, and toluene). Moreover, this electrochemical pesticide sensor achieved a very low limit of detection (LOD) in the 10-7 molar level with a high selectivity among all tested analytes. The LOD for each pesticide ranged from 0.29 to 0.61 μM, revealing the ability to define the maximum residue limit in food. In short, our enzyme-free CuO NR sensor is a promising platform to deliver a fast, low-cost, and reliable pesticide detection unit.

scholarly journals Detection of Mercury Ion with High Sensitivity and Selectivity Using a DNA/Graphene Oxide Hybrid Immobilized on Glass Slides

Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 300
Author(s):  
Li Gao ◽  
Qiuxiang Lv ◽  
Ni Xia ◽  
Yuanwei Lin ◽  
Feng Lin ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
High Selectivity ◽  
Limit Of Detection ◽  
Low Cost ◽  
High Sensitivity ◽  
Mercury Ions ◽  
Research Areas ◽  
Glass Slides ◽  
Highly Sensitive ◽  
Sensitivity And Selectivity

Excessive mercury ions (Hg2+) cause great pollution to soil/water and pose a major threat to human health. The high sensitivity and high selectivity in the Hg2+ detection demonstrated herein are significant for the research areas of analytical chemistry, chemical biology, physical chemistry, drug discovery, and clinical diagnosis. In this study, a series of simple, low-cost, and highly sensitive biochips based on a graphene oxide (GO)/DNA hybrid was developed. Hg2+ is detected with high sensitivity and selectivity by GO/DNA hybrid biochips immobilized on glass slides. The performance of the biosensors can be improved by introducing more phosphorothioate sites and complementary bases. The best limit of detection of the biochips is 0.38 nM with selectivity of over 10:1. This sensor was also used for Hg2+ detection in Dendrobium. The results show this biochip is promising for Hg2+ detection.

Recent Trends in Development of Nanomaterials Based Green Analytical Methods for Environmental Remediation

2020 ◽  
Vol 16 ◽  
Author(s):  
Sidra Amin ◽  
Amber R. Solangi ◽  
Dilawar Hassan ◽  
Nadir Hussain ◽  
Jamil Ahmed ◽  
...  
Keyword(s):  
Optical Sensors ◽  
Environmental Remediation ◽  
Environmental Chemistry ◽  
Limit Of Detection ◽  
Environmental Pollutants ◽  
Toxic Metal ◽  
Electrochemical Analysis ◽  
Good Choice ◽  
Nano Materials ◽  
Limit Of Quantification

Background: In recent years, the occurrence and fate of environmental pollutants has been recognized as one of the emerging issues in environmental chemistry. A survey documented about a wide variety of these pollutants, which are often detected in our environment and these are major cause of shortened life spans and the global warming. These pollutants include toxic metal, pesticides, fertilizers, drugs and dyes released into soil and major water bodies. The presence of these contaminants causes major disturbance in eco-system’s balance. To tackle these issues many technological improvements are made to detect minute contaminations. The latest issue being answered by the scientists is the use of green nano materials as sensors which are economical, instant and give much better results at low concentrations and can be used for the field measurements resulting in no dangerous by-product that could lead to more environmental contamination. Nano materials are known for their wide band gap, enhanced physical and optical properties with option of tuneablity as per need, by optimizing certain parameters. They are proved to be good choice for analytical/optical sensors with high sensitivity. Objective: This review holds information about multiple methods that use green nanomaterials for the analytical assessment of environmental pollutants. UV-Vis spectrophotometry and electrochemical analysis using green and reproducible nanomaterials are the major focus of this review article. To date, there are number of spectrophotometric and electro chemical methods available that have been used for the detection of environmental pollutants such as toxic metals, pesticides and dyes. Conclusion: The use of nanomaterials can drastically change the detection limits due to having large surface area, strong catalytic properties, and tunable possibility. With the use of nano materials, lower than the marked limit of detection and limit of quantification were seen when compared with previously reported work. The used nano-materials could be washed, dried, and reused, which makes the methods more proficient, cost effective and environmentally friendly.

Tools of Transformation: Appropriate Technology in U.S. Countercultural Literature

2012 ◽  
Vol 44 (2) ◽  
pp. 75-93
Author(s):  
Peter Mortensen
Keyword(s):  
Low Cost ◽  
Appropriate Technology ◽  
Small Scale ◽  
Environmental Transformation ◽  
Buckminster Fuller ◽  
1960S And 1970S ◽  
The 1960S ◽  
Environmentally Sound ◽  
User Friendly ◽  
Second Wave

This essay takes its cue from second-wave ecocriticism and from recent scholarly interest in the “appropriate technology” movement that evolved during the 1960s and 1970s in California and elsewhere. “Appropriate technology” (or AT) refers to a loosely-knit group of writers, engineers and designers active in the years around 1970, and more generally to the counterculture’s promotion, development and application of technologies that were small-scale, low-cost, user-friendly, human-empowering and environmentally sound. Focusing on two roughly contemporary but now largely forgotten American texts Sidney Goldfarb’s lyric poem “Solar-Heated-Rhombic-Dodecahedron” (1969) and Gurney Norman’s novel Divine Right’s Trip (1971)—I consider how “hip” literary writers contributed to eco-technological discourse and argue for the 1960s counterculture’s relevance to present-day ecological concerns. Goldfarb’s and Norman’s texts interest me because they conceptualize iconic 1960s technologies—especially the Buckminster Fuller-inspired geodesic dome and the Volkswagen van—not as inherently alienating machines but as tools of profound individual, social and environmental transformation. Synthesizing antimodernist back-to-nature desires with modernist enthusiasm for (certain kinds of) machinery, these texts adumbrate a humanity- and modernity-centered post-wilderness model of environmentalism that resonates with the dilemmas that we face in our increasingly resource-impoverished, rapidly warming and densely populated world.

scholarly journals A rapid, accurate, scalable, and portable testing system for COVID-19 diagnosis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guanhua Xun ◽  
Stephan Thomas Lane ◽  
Vassily Andrew Petrov ◽  
Brandon Elliott Pepa ◽  
Huimin Zhao
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
High Volume ◽  
N Gene ◽  
Testing System ◽  
Target Sequence ◽  
One Pot ◽  
Sequence Detection ◽  
Highly Sensitive ◽  
Speed Accuracy

AbstractThe need for rapid, accurate, and scalable testing systems for COVID-19 diagnosis is clear and urgent. Here, we report a rapid Scalable and Portable Testing (SPOT) system consisting of a rapid, highly sensitive, and accurate assay and a battery-powered portable device for COVID-19 diagnosis. The SPOT assay comprises a one-pot reverse transcriptase-loop-mediated isothermal amplification (RT-LAMP) followed by PfAgo-based target sequence detection. It is capable of detecting the N gene and E gene in a multiplexed reaction with the limit of detection (LoD) of 0.44 copies/μL and 1.09 copies/μL, respectively, in SARS-CoV-2 virus-spiked saliva samples within 30 min. Moreover, the SPOT system is used to analyze 104 clinical saliva samples and identified 28/30 (93.3% sensitivity) SARS-CoV-2 positive samples (100% sensitivity if LoD is considered) and 73/74 (98.6% specificity) SARS-CoV-2 negative samples. This combination of speed, accuracy, sensitivity, and portability will enable high-volume, low-cost access to areas in need of urgent COVID-19 testing capabilities.

scholarly journals Rapid and Sensitive Detection of miRNA Based on AC Electrokinetic Capacitive Sensing for Point-of-Care Applications

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3985
Author(s):  
Nan Wan ◽  
Yu Jiang ◽  
Jiamei Huang ◽  
Rania Oueslati ◽  
Shigetoshi Eda ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Clinical Diagnostics ◽  
Detection Methods ◽  
Capacitive Sensing ◽  
Application Potential ◽  
Mirna Detection ◽  
Mirna 25 ◽  
Low Sensitivity

A sensitive and efficient method for microRNAs (miRNAs) detection is strongly desired by clinicians and, in recent years, the search for such a method has drawn much attention. There has been significant interest in using miRNA as biomarkers for multiple diseases and conditions in clinical diagnostics. Presently, most miRNA detection methods suffer from drawbacks, e.g., low sensitivity, long assay time, expensive equipment, trained personnel, or unsuitability for point-of-care. New methodologies are needed to overcome these limitations to allow rapid, sensitive, low-cost, easy-to-use, and portable methods for miRNA detection at the point of care. In this work, to overcome these shortcomings, we integrated capacitive sensing and alternating current electrokinetic effects to detect specific miRNA-16b molecules, as a model, with the limit of detection reaching 1.0 femto molar (fM) levels. The specificity of the sensor was verified by testing miRNA-25, which has the same length as miRNA-16b. The sensor we developed demonstrated significant improvements in sensitivity, response time and cost over other miRNA detection methods, and has application potential at point-of-care.

scholarly journals Demonstration of a Label-Free and Low-Cost Optical Cavity-Based Biosensor Using Streptavidin and C-Reactive Protein

Biosensors ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Donggee Rho ◽  
Seunghyun Kim
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Optical Cavity ◽  
Sample Volume ◽  
Small Sample ◽  
Label Free ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Cavity Structure

An optical cavity-based biosensor (OCB) has been developed for point-of-care (POC) applications. This label-free biosensor employs low-cost components and simple fabrication processes to lower the overall cost while achieving high sensitivity using a differential detection method. To experimentally demonstrate its limit of detection (LOD), we conducted biosensing experiments with streptavidin and C-reactive protein (CRP). The optical cavity structure was optimized further for better sensitivity and easier fluid control. We utilized the polymer swelling property to fine-tune the optical cavity width, which significantly improved the success rate to produce measurable samples. Four different concentrations of streptavidin were tested in triplicate, and the LOD of the OCB was determined to be 1.35 nM. The OCB also successfully detected three different concentrations of human CRP using biotinylated CRP antibody. The LOD for CRP detection was 377 pM. All measurements were done using a small sample volume of 15 µL within 30 min. By reducing the sensing area, improving the functionalization and passivation processes, and increasing the sample volume, the LOD of the OCB are estimated to be reduced further to the femto-molar range. Overall, the demonstrated capability of the OCB in the present work shows great potential to be used as a promising POC biosensor.

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