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 Electrochemical Properties of Screen-Printed Carbon Nano-Onion Electrodes

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3884
Author(s):  
Loanda R. Cumba ◽  
Adalberto Camisasca ◽  
Silvia Giordani ◽  
Robert J. Forster
Keyword(s):  
High Performance ◽  
Electrode Materials ◽  
Limit Of Detection ◽  
Low Cost ◽  
Analytical Sensitivity ◽  
High Performing ◽  
Carbon Particles ◽  
Screen Printed Electrodes ◽  
Ink Formulation ◽  
Screen Printed

The properties of carbon nano-onions (CNOs) make them attractive electrode materials/additives for the development of low-cost, simple to use and highly sensitive Screen Printed Electrodes (SPEs). Here, we report the development of the first CNO-based ink for the fabrication of low-cost and disposable electrodes, leading to high-performance sensors. Achieving a true dispersion of CNOs is intrinsically challenging and a key aspect of the ink formulation. The screen-printing ink formulation is achieved by carefully selecting and optimising the conductive materials (graphite (GRT) and CNOs), the polymer binder, the organic solvent and the plasticiser. Our CNO/GRT-based screen-printed electrodes consist of an interconnected network of conducting carbon particles with a uniform distribution. Electrochemical studies show a heterogeneous electron transfer rate constant of 1.3 ± 0.7 × 10−3 cm·s−1 and a higher current density than the ferrocene/ferrocenium coupled to a commercial graphite SPEs. In addition, the CNO/GRT SPE can detect dopamine in the concentration range of 10.0–99.9 µM with a limit of detection of 0.92 µM (N = 3). They exhibit a higher analytical sensitivity than the commercial graphite-based SPE, with a 4-fold improvement observed. These results open up the possibility of using high-performing CNO-based SPEs for electrochemical applications including sensors, battery electrodes and electrocatalysis.

Polyaniline as a Sacrificing Template for the Synthesis of Ultra-small Co3O4 Nanoparticles for the Sensitive and Selective Detection of Methotrexate (MTX)

2021 ◽  
Author(s):  
Irum Naz Qureshi ◽  
Aneela Tahira ◽  
Khoulwod Aljadoa ◽  
Ali M. Alsalme ◽  
Asma A. Al-Othman ◽  
...  
Keyword(s):  
Electrochemical Sensors ◽  
Limit Of Detection ◽  
Low Cost ◽  
Metal Oxide Nanoparticles ◽  
Linear Sweep Voltammetry ◽  
Co3o4 Nanoparticles ◽  
X Ray Diffraction ◽  
Highly Sensitive ◽  
Wide Range ◽  
Average Size

Abstract The successful monitoring of the anticancer drugs using nanostructured materials is very important but very challenging task. Beside this, uniform and ultra-small size of metal oxide nanoparticles is highly needed in order to enhance the catalytic activity which could result into the development of sensitive and selective electrochemical sensors for methotrexate (MTX). For this purpose, we have used a simple approach involving the polyaniline (PANI) as a sacrificing template for the growth of uniform and ultra-small Co3O4 nanoparticles by hydrothermal method. The structure, shape, composition and phase purity were studied by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform Infrared (FTIR) techniques. The average size of Co3O4 nanoparticles was below 50 nm. The cubic crystallography is confirmed for the Co3O4 nanoparticles. The electrochemical properties of PANI assisted Co3O4 nanoparticles for MTX drug was evaluated by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) in Britton–Robinson buffer (BRB) of pH 3.5. The PANI assisted Co3O4 nanoparticles were found highly sensitive for the MTX drug and exhibited a linear range from 5-75µM of MTX and limit of detection for the modified electrode was estimated 1.98µM. The proposed electrochemical sensor is low cost, simple, highly sensitive and selective towards MTX detection. The synthetic methodology using the conducting polymer as a sacrificing template for the growth of controlled and ultra-small Co3O4 nanoparticles can be utilized for the wide range of electrochemical applications.

scholarly journals Electrochemical Sensors Based on Conducting Polymers for the Aqueous Detection of Biologically Relevant Molecules

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 252
Author(s):  
Álvaro Terán-Alcocer ◽  
Francisco Bravo-Plascencia ◽  
Carlos Cevallos-Morillo ◽  
Alex Palma-Cando
Keyword(s):  
Conducting Polymers ◽  
Building Materials ◽  
Electrochemical Sensors ◽  
Limit Of Detection ◽  
Low Cost ◽  
Relevant Literature ◽  
Liquid Solution ◽  
Morphological Characterization ◽  
Special Focus

Electrochemical sensors appear as low-cost, rapid, easy to use, and in situ devices for determination of diverse analytes in a liquid solution. In that context, conducting polymers are much-explored sensor building materials because of their semiconductivity, structural versatility, multiple synthetic pathways, and stability in environmental conditions. In this state-of-the-art review, synthetic processes, morphological characterization, and nanostructure formation are analyzed for relevant literature about electrochemical sensors based on conducting polymers for the determination of molecules that (i) have a fundamental role in the human body function regulation, and (ii) are considered as water emergent pollutants. Special focus is put on the different types of micro- and nanostructures generated for the polymer itself or the combination with different materials in a composite, and how the rough morphology of the conducting polymers based electrochemical sensors affect their limit of detection. Polypyrroles, polyanilines, and polythiophenes appear as the most recurrent conducting polymers for the construction of electrochemical sensors. These conducting polymers are usually built starting from bifunctional precursor monomers resulting in linear and branched polymer structures; however, opportunities for sensitivity enhancement in electrochemical sensors have been recently reported by using conjugated microporous polymers synthesized from multifunctional monomers.

scholarly journals A Low-Cost Multi-Parameter Water Quality Monitoring System

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3775
Author(s):  
Arif Ul Alam ◽  
Dennis Clyne ◽  
M. Jamal Deen
Keyword(s):  
Water Quality ◽  
Monitoring System ◽  
Electrochemical Sensors ◽  
Limit Of Detection ◽  
Low Cost ◽  
Water Quality Monitoring ◽  
Water Monitoring ◽  
Quality Monitoring ◽  
Sensor Data ◽  
Skilled Workers

Multi-parameter water quality monitoring is crucial in resource-limited areas to provide persistent water safety. Conventional water monitoring techniques are time-consuming, require skilled personnel, are not user-friendly and are incompatible with operating on-site. Here, we develop a multi-parameter water quality monitoring system (MWQMS) that includes an array of low-cost, easy-to-use, high-sensitivity electrochemical sensors, as well as custom-designed sensor readout circuitry and smartphone application with wireless connectivity. The system overcomes the need of costly laboratory-based testing methods and the requirement of skilled workers. The proposed MWQMS system can simultaneously monitor pH, free chlorine, and temperature with sensitivities of 57.5 mV/pH, 186 nA/ppm and 16.9 mV/°C, respectively, as well as sensing of BPA with <10 nM limit of detection. The system also provides seamless interconnection between transduction of the sensors’ signal, signal processing, wireless data transfer and smartphone app-based operation. This interconnection was accomplished by fabricating nanomaterial and carbon nanotube-based sensors on a common substrate, integrating these sensors to a readout circuit and transmitting the sensor data to an Android application. The MWQMS system provides a general platform technology where an array of other water monitoring sensors can also be easily integrated and programmed. Such a system can offer tremendous opportunity for a broad range of environmental monitoring applications.

scholarly journals Selective and self-validating breath-level detection of hydrogen sulfide in humid air by gold nanoparticle-functionalized nanotube arrays

Nano Research ◽  
2021 ◽  
Author(s):  
Luis Antonio Panes-Ruiz ◽  
Leif Riemenschneider ◽  
Mohamad Moner Al Chawa ◽  
Markus Löffler ◽  
Bernd Rellinghaus ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Room Temperature ◽  
Sensor Array ◽  
High Selectivity ◽  
Electrochemical Sensors ◽  
Gas Sensing ◽  
Limit Of Detection ◽  
Electrical Characteristics ◽  
Sensor Fabrication ◽  
Walled Carbon Nanotubes

AbstractWe demonstrate the selective detection of hydrogen sulfide at breath concentration levels under humid airflow, using a self-validating 64-channel sensor array based on semiconducting single-walled carbon nanotubes (sc-SWCNTs). The reproducible sensor fabrication process is based on a multiplexed and controlled dielectrophoretic deposition of sc-SWCNTs. The sensing area is functionalized with gold nanoparticles to address the detection at room temperature by exploiting the affinity between gold and sulfur atoms of the gas. Sensing devices functionalized with an optimized distribution of nanoparticles show a sensitivity of 0.122%/part per billion (ppb) and a calculated limit of detection (LOD) of 3 ppb. Beyond the self-validation, our sensors show increased stability and higher response levels compared to some commercially available electrochemical sensors. The cross-sensitivity to breath gases NH3 and NO is addressed demonstrating the high selectivity to H2S. Finally, mathematical models of sensors’ electrical characteristics and sensing responses are developed to enhance the differentiation capabilities of the platform to be used in breath analysis applications.

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 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.

scholarly journals Electrochemical Sensor Based on Nanodiamonds and Manioc Starch for Detection of Tetracycline

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Wilson Silva Fernandes-Junior ◽  
Leticia Fernanda Zaccarin ◽  
Geiser Gabriel Oliveira ◽  
Paulo Roberto de Oliveira ◽  
Cristiane Kalinke ◽  
...  
Keyword(s):  
Electrochemical Sensor ◽  
Electrochemical Sensors ◽  
Dynamic Range ◽  
Limit Of Detection ◽  
Low Cost ◽  
Polymeric Materials ◽  
Relative Standard ◽  
Repeatability And Reproducibility ◽  
High Repeatability

The use of nanostructured materials is already well-known as a powerful tool in the development of electrochemical sensors. Among several immobilization strategies of nanomaterials in the development of electrochemical sensors, the use of low-cost and environmentally friendly polymeric materials is highlighted. In this context, a new nanostructured biocomposite electrode is proposed as an electrochemical sensor for the analysis and determination of tetracycline. The composite electrode consists of a modified glassy carbon electrode (GCE) with a nanodiamond-based (ND) and manioc starch biofilm (MS), called ND-MS/GCE. The proposed sensor showed better electrochemical performance in the presence of tetracycline in comparison to the unmodified electrode, which was attributed to the increase in the electroactive surface area due to the presence of nanodiamonds. A linear dynamic range from 5.0 × 10 − 6 to 1.8 × 10 − 4  mol L−1 and a limit of detection of 2.0 × 10 − 6  mol L−1 were obtained for the proposed sensor. ND-MS/GCE exhibited high repeatability and reproducibility for successive measurements with a relative standard deviation (RSD) of 6.3% and 1.5%, respectively. The proposed electrode was successfully applied for the detection of tetracycline in different kinds of water samples, presenting recoveries ranging from 86 to 112%.

scholarly journals Deployment, Calibration, and Cross-Validation of Low-Cost Electrochemical Sensors for Carbon Monoxide, Nitrogen Oxides, and Ozone for an Epidemiological Study

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4214
Author(s):  
Christopher Zuidema ◽  
Cooper S. Schumacher ◽  
Elena Austin ◽  
Graeme Carvlin ◽  
Timothy V. Larson ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Exposure Assessment ◽  
Epidemiological Study ◽  
Electrochemical Sensors ◽  
Low Cost ◽  
Puget Sound ◽  
Ambient Air ◽  
Ambient Air Pollution ◽  
Calibration Models ◽  
Study Participants

We designed and built a network of monitors for ambient air pollution equipped with low-cost gas sensors to be used to supplement regulatory agency monitoring for exposure assessment within a large epidemiological study. This paper describes the development of a series of hourly and daily field calibration models for Alphasense sensors for carbon monoxide (CO; CO-B4), nitric oxide (NO; NO-B4), nitrogen dioxide (NO2; NO2-B43F), and oxidizing gases (OX-B431)—which refers to ozone (O3) and NO2. The monitor network was deployed in the Puget Sound region of Washington, USA, from May 2017 to March 2019. Monitors were rotated throughout the region, including at two Puget Sound Clean Air Agency monitoring sites for calibration purposes, and over 100 residences, including the homes of epidemiological study participants, with the goal of improving long-term pollutant exposure predictions at participant locations. Calibration models improved when accounting for individual sensor performance, ambient temperature and humidity, and concentrations of co-pollutants as measured by other low-cost sensors in the monitors. Predictions from the final daily models for CO and NO performed the best considering agreement with regulatory monitors in cross-validated root-mean-square error (RMSE) and R2 measures (CO: RMSE = 18 ppb, R2 = 0.97; NO: RMSE = 2 ppb, R2 = 0.97). Performance measures for NO2 and O3 were somewhat lower (NO2: RMSE = 3 ppb, R2 = 0.79; O3: RMSE = 4 ppb, R2 = 0.81). These high levels of calibration performance add confidence that low-cost sensor measurements collected at the homes of epidemiological study participants can be integrated into spatiotemporal models of pollutant concentrations, improving exposure assessment for epidemiological inference.

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.

Sign in / Sign up

Export Citation Format

Share Document