scholarly journals Electrochemical (Bio)Sensors for Pesticides Detection Using Screen-Printed Electrodes

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.

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3884
Author(s):  
Loanda R. Cumba ◽  
Adalberto Camisasca ◽  
Silvia Giordani ◽  
Robert J. Forster

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.


Author(s):  
Minhaz Uddin Ahmed ◽  
Mohammad Mosharraf Hossain ◽  
Mohammadali Safavieh ◽  
Yen Lu Wong ◽  
Ibrahim Abd Rahman ◽  
...  

2016 ◽  
Vol 35 (2) ◽  
pp. 53-85 ◽  
Author(s):  
Zorione Herrasti ◽  
Erica de la Serna ◽  
Gisela Ruiz-Vega ◽  
Eva Baldrich

AbstractElectrochemical magnetoimmunosensors combine a number of issues that guarantee extremely high performance and also compatibility with the study of complex sample matrices. First, analyte immunocapture exploits the high affinity and specificity of antibodies. Second, magnetic particles (MP) provide faster and more efficient immunocapture than binding on two-dimensional structures, separation from nontarget sample components, and concentration of the target analyte. Finally, electrochemical detection supplies sensitivity and fast signal generation using robust and potentially miniaturized measurement equipment and transducers. On the contrary, MP handling is slightly more complex for end-users and more difficult to integrate in point-of-care devices than the manipulation of a classical biosensor. Attempts have been made to automate immunomagnetic binding, and the first robotized systems and platforms for the fluorescent and spectrophotometric detection of magnetoimmunoassays have already reached the market. Among the different types of electrodes available, screen-printed electrodes (SPE) stand out because of their low production cost and yet acceptable performance and interdevice reproducibility, which make them an excellent choice for analytical applications. In addition, each SPE entails a whole electrochemical cell stamped on a planar physical substrate, which makes it possible detection in small volumes and is especially favorable for the magnetic confinement of MP and the integration of microfluidic structures. In this article, we discuss the advantages obtained by using SPE and MP for the production of electrochemical magnetoimmunosensors and the clues for the successful development of such devices. We then revise some of the most outstanding works published in the literature.


Proceedings ◽  
2017 ◽  
Vol 1 (8) ◽  
pp. 842 ◽  
Author(s):  
Davide Migliorelli ◽  
Silvia Generelli ◽  
Nicolas Glaser ◽  
Mirta Viviani ◽  
Lea Mühlebach ◽  
...  

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yehe Liu ◽  
Andrew M. Rollins ◽  
Richard M. Levenson ◽  
Farzad Fereidouni ◽  
Michael W. Jenkins

AbstractSmartphone microscopes can be useful tools for a broad range of imaging applications. This manuscript demonstrates the first practical implementation of Microscopy with Ultraviolet Surface Excitation (MUSE) in a compact smartphone microscope called Pocket MUSE, resulting in a remarkably effective design. Fabricated with parts from consumer electronics that are readily available at low cost, the small optical module attaches directly over the rear lens in a smartphone. It enables high-quality multichannel fluorescence microscopy with submicron resolution over a 10× equivalent field of view. In addition to the novel optical configuration, Pocket MUSE is compatible with a series of simple, portable, and user-friendly sample preparation strategies that can be directly implemented for various microscopy applications for point-of-care diagnostics, at-home health monitoring, plant biology, STEM education, environmental studies, etc.


Author(s):  
Antonia Perju ◽  
Nongnoot Wongkaew

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.


PLoS ONE ◽  
2018 ◽  
Vol 13 (5) ◽  
pp. e0196656 ◽  
Author(s):  
Rui S. Gomes ◽  
Felismina T. C. Moreira ◽  
Ruben Fernandes ◽  
M. Goreti F. Sales

2020 ◽  
Author(s):  
Alain Townsend ◽  
Pramila Rijal ◽  
Julie Xiao ◽  
Tiong Kit Tan ◽  
Kuan-Ying A Huang ◽  
...  

ABSTRACTSerological detection of antibodies to SARS-CoV-2 is essential for establishing rates of seroconversion in populations, detection of seroconversion after vaccination, and for seeking evidence for a level of antibody that may be protective against COVID-19 disease. Several high-performance commercial tests have been described, but these require centralised laboratory facilities that are comparatively expensive, and therefore not available universally. Red cell agglutination tests have a long history in blood typing, and general serology through linkage of reporter molecules to the red cell surface. They do not require special equipment, are read by eye, have short development times, low cost and can be applied as a Point of Care Test (POCT). We describe a red cell agglutination test for the detection of antibodies to the SARS-CoV-2 receptor binding domain (RBD). We show that the Haemagglutination Test (“HAT”) has a sensitivity of 90% and specificity of 99% for detection of antibodies after a PCR diagnosed infection. The HAT can be titrated, detects rising titres in the first five days of hospital admission, correlates well with a commercial test that detects antibodies to the RBD, and can be applied as a point of care test. The developing reagent is composed of a previously described nanobody to a conserved glycophorin A epitope on red cells, linked to the RBD from SARS-CoV-2. It can be lyophilised for ease of shipping. We have scaled up production of this reagent to one gram, which is sufficient for ten million tests, at a cost of ∼0.27 UK pence per test well. Aliquots of this reagent are ready to be supplied to qualified groups anywhere in the world that need to detect antibodies to SARS-CoV-2, but do not have the facilities for high throughput commercial tests.


Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1715 ◽  
Author(s):  
Abdul Shakoor ◽  
James Grant ◽  
Marco Grande ◽  
David. R. S. Cumming

A range of nanophotonic sensors composed of different materials and device configurations have been developed over the past two decades. These sensors have achieved high performance in terms of sensitivity and detection limit. The size of onchip nanophotonic sensors is also small and they are regarded as a strong candidate to provide the next generation sensors for a range of applications including chemical and biosensing for point-of-care diagnostics. However, the apparatus used to perform measurements of nanophotonic sensor chips is bulky, expensive and requires experts to operate them. Thus, although integrated nanophotonic sensors have shown high performance and are compact themselves their practical applications are limited by the lack of a compact readout system required for their measurements. To achieve the aim of using nanophotonic sensors in daily life it is important to develop nanophotonic sensors which are not only themselves small, but their readout system is also portable, compact and easy to operate. Recognizing the need to develop compact readout systems for onchip nanophotonic sensors, different groups around the globe have started to put efforts in this direction. This review article discusses different works carried out to develop integrated nanophotonic sensors with compact readout systems, which are divided into two categories; onchip nanophotonic sensors with monolithically integrated readout and onchip nanophotonic sensors with separate but compact readout systems.


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