scholarly journals Nanoelectrode Arrays Fabricated by Thermal Nanoimprint Lithography for Biosensing Application

Biosensors ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 90
Author(s):  
Alessandra Zanut ◽  
Alessandro Cian ◽  
Nicola Cefarin ◽  
Alessandro Pozzato ◽  
Massimo Tormen
Keyword(s):  
Nanoimprint Lithography ◽  
Electrochemical Sensors ◽  
Low Cost ◽  
Scale Up ◽  
Electrochemical Sensing ◽  
Electrical Measurements ◽  
Boron Doped Diamond ◽  
Sensing Platform ◽  
Increased Sensitivity ◽  
Gliadin Protein

Electrochemical sensors are devices capable of detecting molecules and biomolecules in solutions and determining the concentration through direct electrical measurements. These systems can be miniaturized to a size less than 1 µm through the creation of small-size arrays of nanoelectrodes (NEA), offering advantages in terms of increased sensitivity and compactness. In this work, we present the fabrication of an electrochemical platform based on an array of nanoelectrodes (NEA) and its possible use for the detection of antigens of interest. NEAs were fabricated by forming arrays of nanoholes on a thin film of polycarbonate (PC) deposited on boron-doped diamond (BDD) macroelectrodes by thermal nanoimprint lithography (TNIL), which demonstrated to be a highly reliable and reproducible process. As proof of principle, gliadin protein fragments were physisorbed on the polycarbonate surface of NEAs and detected by immuno-indirect assay using a secondary antibody labelled with horseradish peroxidase (HRP). This method allows a successful detection of gliadin, in the range of concentration of 0.5–10 μg/mL, by cyclic voltammetry taking advantage from the properties of NEAs to strongly suppress the capacitive background signal. We demonstrate that the characteristics of the TNIL technology in the fabrication of high-resolution nanostructures together with their low-cost production, may allow to scale up the production of NEAs-based electrochemical sensing platform to monitor biochemical molecules for both food and biomedical applications.

scholarly journals Molecularly Imprinted Polymers Combined with Electrochemical Sensors for Food Contaminants Analysis

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4607
Author(s):  
Dounia Elfadil ◽  
Abderrahman Lamaoui ◽  
Flavio Della Pelle ◽  
Aziz Amine ◽  
Dario Compagnone
Keyword(s):  
Food Safety ◽  
Molecularly Imprinted Polymers ◽  
Electrochemical Sensors ◽  
Low Cost ◽  
Electrochemical Analysis ◽  
Ease Of Use ◽  
Electrochemical Sensing ◽  
Food Contaminants ◽  
Molecularly Imprinted ◽  
Imprinted Polymers

Detection of relevant contaminants using screening approaches is a key issue to ensure food safety and respect for the regulatory limits established. Electrochemical sensors present several advantages such as rapidity; ease of use; possibility of on-site analysis and low cost. The lack of selectivity for electrochemical sensors working in complex samples as food may be overcome by coupling them with molecularly imprinted polymers (MIPs). MIPs are synthetic materials that mimic biological receptors and are produced by the polymerization of functional monomers in presence of a target analyte. This paper critically reviews and discusses the recent progress in MIP-based electrochemical sensors for food safety. A brief introduction on MIPs and electrochemical sensors is given; followed by a discussion of the recent achievements for various MIPs-based electrochemical sensors for food contaminants analysis. Both electropolymerization and chemical synthesis of MIP-based electrochemical sensing are discussed as well as the relevant applications of MIPs used in sample preparation and then coupled to electrochemical analysis. Future perspectives and challenges have been eventually given.

scholarly journals An Electrochemical Sensor Based on Gold Nanodendrite/Surfactant Modified Electrode for Bisphenol A Detection

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Nguyen Thi Lien ◽  
Le Quoc Hung ◽  
Nguyen Tien Hoang ◽  
Vu Thi Thu ◽  
Dau Thi Ngoc Nga ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Electrochemical Sensors ◽  
Differential Pulse ◽  
Electrochemical Sensing ◽  
Fluorescence Measurements ◽  
Sensing Platform ◽  
Electrochemical Window ◽  
Galvanostatic Deposition ◽  
Bisphenol A Detection ◽  
Good Agreement

In the present work, we reported the simple way to fabricate an electrochemical sensing platform to detect Bisphenol A (BPA) using galvanostatic deposition of Au on a glassy carbon electrode covered by cetyltrimethylammonium bromide (CTAB). This material (CTAB) enhances the sensitivity of electrochemical sensors with respect to the detection of BPA. The electrochemical response of the modified GCE to BPA was investigated by cyclic voltammetry and differential pulse voltammetry. The results displayed a low detection limit (22 nm) and a linear range from 0.025 to 10 µm along side with high reproducibility (RSD = 4.9% for seven independent sensors). Importantly, the prepared sensors were selective enough against interferences with other pollutants in the same electrochemical window. Notably, the presented sensors have already proven their ability in detecting BPA in real plastic water drinking bottle samples with high accuracy (recovery range = 96.60%–102.82%) and it is in good agreement with fluorescence measurements.

Intelligent analysis of maleic hydrazide using a simple electrochemical sensor coupled with machine learning

2021 ◽  
Vol 13 (39) ◽  
pp. 4662-4673
Author(s):  
Lulu Xu ◽  
Ruimei Wu ◽  
Xiaoyu Zhu ◽  
Xiaoqiang Wang ◽  
Xiang Geng ◽  
...  
Keyword(s):  
Machine Learning ◽  
Electrochemical Sensor ◽  
Maleic Hydrazide ◽  
Low Cost ◽  
Electrochemical Sensing ◽  
Flexible Electrode ◽  
Porous Graphene ◽  
Sensing Platform ◽  
Intelligent Analysis

A simple intelligent electrochemical sensing platform based on a low-cost disposable laser-induced porous graphene flexible electrode for maleic hydrazide coupled with machine learning was successfully designed.

scholarly journals Paper-based aptamer-antibody biosensor for gluten detection in a deep eutectic solvent (DES)

2021 ◽  
Author(s):  
Rossella Svigelj ◽  
Nicolò Dossi ◽  
Cristian Grazioli ◽  
Rosanna Toniolo
Keyword(s):  
Dynamic Range ◽  
Limit Of Detection ◽  
Low Cost ◽  
Deep Eutectic Solvent ◽  
Electrochemical Sensing ◽  
Sensing Platform ◽  
Screen Printed Carbon Electrode ◽  
Highly Sensitive ◽  
Rapid Tests

AbstractPaper has been widely employed as cheap material for the development of a great number of sensors such as pregnancy tests, strips to measure blood sugar, and COVID-19 rapid tests. The need for new low-cost analytical devices is growing, and consequently the use of these platforms will be extended to different assays, both for the final consumer and within laboratories. This work describes a paper-based electrochemical sensing platform that uses a paper disc conveniently modified with recognition molecules and a screen-printed carbon electrode (SPCE) to achieve the detection of gluten in a deep eutectic solvent (DES). This is the first method coupling a paper biosensor based on aptamers and antibodies with the DES ethaline. Ethaline proved to be an excellent extraction medium allowing the determination of very low gluten concentrations. The biosensor is appropriate for the determination of gluten with a limit of detection (LOD) of 0.2 mg L−1 of sample; it can detect gluten extracted in DES with a dynamic range between 0.2 and 20 mg L−1 and an intra-assay coefficient of 10.69%. This approach can be of great interest for highly gluten-sensitive people, who suffer from ingestion of gluten quantities well below the legal limit, which is 20 parts per million in foods labeled gluten-free and for which highly sensitive devices are essential. Graphical abstract

scholarly journals Bio- and Biomimetic Receptors for Electrochemical Sensing of Heavy Metal Ions

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6800
Author(s):  
Angela Maria Stortini ◽  
Maria Antonietta Baldo ◽  
Giulia Moro ◽  
Federico Polo ◽  
Ligia Maria Moretto
Keyword(s):  
Inductively Coupled Plasma ◽  
High Performance ◽  
Electrochemical Sensors ◽  
Low Cost ◽  
Environmental Pollutants ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Electrochemical Sensing ◽  
Anthropogenic Sources ◽  
Analytical Tools

Heavy metals ions (HMI), if not properly handled, used and disposed, are a hazard for the ecosystem and pose serious risks for human health. They are counted among the most common environmental pollutants, mainly originating from anthropogenic sources, such as agricultural, industrial and/or domestic effluents, atmospheric emissions, etc. To face this issue, it is necessary not only to determine the origin, distribution and the concentration of HMI but also to rapidly (possibly in real-time) monitor their concentration levels in situ. Therefore, portable, low-cost and high performing analytical tools are urgently needed. Even though in the last decades many analytical tools and methodologies have been designed to this aim, there are still several open challenges. Compared with the traditional analytical techniques, such as atomic absorption/emission spectroscopy, inductively coupled plasma mass spectrometry and/or high-performance liquid chromatography coupled with electrochemical or UV–VIS detectors, bio- and biomimetic electrochemical sensors provide high sensitivity, selectivity and rapid responses within portable and user-friendly devices. In this review, the advances in HMI sensing in the last five years (2016–2020) are addressed. Key examples of bio and biomimetic electrochemical, impedimetric and electrochemiluminescence-based sensors for Hg2+, Cu2+, Pb2+, Cd2+, Cr6+, Zn2+ and Tl+ are described and discussed.

Constructive Optimisation of the Propeller Type Mixing Devices Using the Virtual and Rapid Prototyping

2017 ◽  
Vol 68 (3) ◽  
pp. 453-458 ◽  
Author(s):  
Daniel Besnea ◽  
Alina Spanu ◽  
Iuliana Marlena Prodea ◽  
Gheorghita Tomescu ◽  
Iolanda Constanta Panait
Keyword(s):  
Rapid Prototyping ◽  
Low Cost ◽  
Scale Up ◽  
Three Dimensional ◽  
Rapid Identification ◽  
Multidisciplinary Optimization ◽  
External Diameter ◽  
Process Industries ◽  
Parametric Cad ◽  
Shaft Torque

The paper points out the advantages of rapid prototyping for improving the performances/constructive optimization of mixing devices used in process industries, here exemplified to propeller types ones. The multidisciplinary optimization of the propeller profile affords its design using parametric CAD methods. Starting from the mathematical curve equations proposed for the blade profile, it was determined its three-dimensional virtual model. The challenge has been focused on the variation of propeller pitch and external diameter. Three dimensional ranges were manufactured using the additive manufacturing process with Marker Boot 3D printer. The mixing performances were tested on the mixing equipment measuring the minimum rotational speed and the correspondent shaft torque for complete suspension achieved for each of the three models. The virtual and rapid prototyping method is newly proposed by the authors to obtain the basic data for scale up of the mixing systems, in the case of flexible production (of low quantities), in which both the nature and concentration of the constituents in the final product varies often. It is an efficient and low cost method for the rapid identification of the optimal mixing device configuration, which contributes to the costs reduction and to the growing of the output.

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 Paper-Based Competitive Immunochromatography Coupled with an Enzyme-Modified Electrode to Enable the Wireless Monitoring and Electrochemical Sensing of Cotinine in Urine

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1659
Author(s):  
Nutcha Larpant ◽  
Pramod K. Kalambate ◽  
Tautgirdas Ruzgas ◽  
Wanida Laiwattanapaisal
Keyword(s):  
Glucose Oxidase ◽  
Modified Electrode ◽  
Near Field ◽  
Electrochemical Measurement ◽  
Electrochemical Sensing ◽  
Urine Samples ◽  
Lateral Flow Strip ◽  
Wireless Monitoring ◽  
Sensing Platform ◽  
Combined Strategy

This paper proposes a combined strategy of using paper-based competitive immunochromatography and a near field communication (NFC) tag for wireless cotinine determination. The glucose oxidase labeled cotinine antibody specifically binds free cotinine in a sample, whereas the unoccupied antibody attached to BSA-cotinine at the test line on a lateral flow strip. The glucose oxidase on the strip and an assistant pad in the presence of glucose generated H2O2 and imposed the Ag oxidation on the modified electrode. This enabled monitoring of immunoreaction by either electrochemical measurement or wireless detection. Wireless sensing was realized for cotinine in the range of 100–1000 ng/mL (R2 = 0.96) in PBS medium. Undiluted urine samples from non-smokers exhibited an Ag-oxidation rate three times higher than the smoker’s urine samples. For 1:8 diluted urine samples (smokers), the proposed paper-based competitive immunochromatography coupled with an enzyme-modified electrode differentiated positive and negative samples and exhibited cotinine discrimination at levels higher than 12 ng/mL. This novel sensing platform can potentially be combined with a smartphone as a reader unit.

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