scholarly journals Eco-Friendly Synthesis of SnO2-Cu Nanocomposites and Evaluation of Their Peroxidase Mimetic Activity

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1798
Author(s):  
Ravi Mani Tripathi ◽  
Sang J. Chung
Keyword(s):  
Ph Value ◽  
Point Of Care ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Cost Effective ◽  
Promising Alternative ◽  
Enzyme Mimetic ◽  
Peroxidase Mimetic ◽  
Point Of Care Diagnostics ◽  
Cost Effective Method

The enzyme mimetic activity of nanomaterials has been applied in colorimetric assays and point-of-care diagnostics. Several nanomaterials have been exploited for their peroxidase mimetic activity toward 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide. However, an efficient nanomaterial for the rapid and strong oxidation of TMB remains a strategic challenge. Therefore, in this study, we developed copper-loaded tin oxide (SnO2-Cu) nanocomposites that rapidly oxidize TMB. These nanocomposites have strong absorption at 650 nm and can be used for highly sensitive colorimetric detection. An environmentally friendly (green), rapid, easy, and cost-effective method was developed for the synthesis of these nanocomposites, which were characterized using ultraviolet-visible, energy-dispersive X-ray, and Fourier-transform infrared spectroscopy, as well as scanning electron microscopy. This is the first green synthesis of SnO2-Cu nanocomposites. Their enzyme mimetic activity, which was first studied here, was found to be strongly dependent on the temperature and pH value of the solution. The synthesized nanocomposites have the advantages of low cost, high stability, and ease of preparation for enzyme mimetic applications. Hence, SnO2-Cu nanocomposites are a promising alternative to peroxidase enzymes in colorimetric point-of-care diagnostics.

scholarly journals A Disposable Paper-Based Electrochemical Sensor Made of Pencil Graphite and Its Modification with Au for Detection of Glucose in Alkaline Solutions

2020 ◽  
Author(s):  
Mustafa Sen
Keyword(s):  
Environmental Monitoring ◽  
Electrochemical Sensor ◽  
Point Of Care ◽  
Low Cost ◽  
Cost Effective ◽  
Alkaline Solutions ◽  
Glucose Detection ◽  
Electrochemical Modification ◽  
Point Of Care Diagnostics

Paper-based sensors have great potential to be used in a variety of fields ranging from environmental monitoring to clinical and point-of-care diagnostics. These sensors are disposable, cost effective, flexible and easy to use. The aim of this study was to fabricate a low cost, disposable, reliable and easy to use paper-based electrochemical sensor and its electrochemical modification with nanostructured Au for glucose detection in alkaline solutions.

scholarly journals Colorimetric Determination of Nitrate after Reduction to Nitrite in a Paper-Based Dip Strip

2021 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Amer Charbaji ◽  
Hojat Heidari-Bafroui ◽  
Nasim Rahmani ◽  
Constantine Anagnostopoulos ◽  
Mohammad Faghri
Keyword(s):  
Limit Of Detection ◽  
Point Of Care ◽  
Low Cost ◽  
Colorimetric Detection ◽  
Water Quality Monitoring ◽  
Colorimetric Determination ◽  
Limit Of Quantification ◽  
Point Of Care Diagnostics ◽  
Reduction Efficiency ◽  
Nitrate And Nitrite

Paper-based microfluidic technology is a relatively new field of research that provides low-cost platforms and sensors for point-of-care diagnostics. While the majority of research in this field has been for biomedical applications, more and more paper-based devices and platforms are being designed and developed for environmental applications, such as water quality monitoring and assessment. One such application is the detection of nitrate in water samples. Colorimetric detection of nitrate by paper-based devices using the Griess assay requires the reduction of nitrate to nitrite before undergoing the reaction. In this paper, we measured the performance of a paper-based dip strip for detecting nitrate and nitrite by calculating its limit of detection and limit of quantification. We also calculated the reduction efficiency of vanadium (III) chloride in the dip strip for detecting nitrate. Our results show that the reduction time of nitrate via vanadium (III) chloride is much longer than that when using zinc microparticles. Our results also show that the performance of the dip strip using vanadium (III) chloride for nitrate detection is not as good as more intricate paper-based devices that have a separate reaction zone with zinc microparticles. The limits of detection and quantification calculated were 3.352 and 7.437 ppm, and the nitrate reduction efficiency varied over the range of nitrate concentrations tested.

scholarly journals A Disposable Paper-Based Electrochemical Sensor Made of Pencil Graphite and Its Modification with Au for Detection of Glucose in Alkaline Solutions

2020 ◽  
Author(s):  
Mustafa Sen
Keyword(s):  
Environmental Monitoring ◽  
Electrochemical Sensor ◽  
Point Of Care ◽  
Low Cost ◽  
Cost Effective ◽  
Alkaline Solutions ◽  
Glucose Detection ◽  
Electrochemical Modification ◽  
Point Of Care Diagnostics

Paper-based sensors have great potential to be used in a variety of fields ranging from environmental monitoring to clinical and point-of-care diagnostics. These sensors are disposable, cost effective, flexible and easy to use. The aim of this study was to fabricate a low cost, disposable, reliable and easy to use paper-based electrochemical sensor and its electrochemical modification with nanostructured Au for glucose detection in alkaline solutions.

scholarly journals A Disposable Paper-Based Electrochemical Sensor Made of Pencil Graphite and Its Modification with Au for Detection of Glucose in Alkaline Solutions

2020 ◽  
Author(s):  
Mustafa Sen
Keyword(s):  
Environmental Monitoring ◽  
Electrochemical Sensor ◽  
Point Of Care ◽  
Low Cost ◽  
Cost Effective ◽  
Alkaline Solutions ◽  
Glucose Detection ◽  
Electrochemical Modification ◽  
Point Of Care Diagnostics

Paper-based sensors have great potential to be used in a variety of fields ranging from environmental monitoring to clinical and point-of-care diagnostics. These sensors are disposable, cost effective, flexible and easy to use. The aim of this study was to fabricate a low cost, disposable, reliable and easy to use paper-based electrochemical sensor and its electrochemical modification with nanostructured Au for glucose detection in alkaline solutions.

scholarly journals Pocket MUSE: an affordable, versatile and high-performance fluorescence microscope using a smartphone

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yehe Liu ◽  
Andrew M. Rollins ◽  
Richard M. Levenson ◽  
Farzad Fereidouni ◽  
Michael W. Jenkins
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
Consumer Electronics ◽  
Practical Implementation ◽  
The Novel ◽  
Point Of Care Diagnostics ◽  
Optical Module ◽  
Optical Configuration ◽  
User Friendly

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.

THEORETICAL ANALYSES FOR LASER MACHINING MICROCHANNELS AND DEMONSTRATION OF THEIR USES IN MANUFACTURE OF A MICROFLUIDIC OPTICAL SWITCH

2006 ◽  
Vol 13 (06) ◽  
pp. 795-802 ◽  
Author(s):  
DANIEL LIM ◽  
ERNA GONDO SANTOSO ◽  
KIM MING TEH ◽  
STEPHEN WAN ◽  
H. Y. ZHENG
Keyword(s):  
Fluid Flow ◽  
Optical Switch ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Cost Effective ◽  
Laser Machining ◽  
Machining Parameters ◽  
Flow Channels ◽  
Cost Effective Method ◽  
Theoretical Analyses

Silicon has been widely used to fabricate microfluidic devices due to the dominance of silicon microfabrication technologies available. In this paper, theoretical analyses are carried out to suggest suitable laser machining parameters to achieve required channel geometries. Based on the analyses, a low-power CO 2 laser was employed to create microchannels in Acrylic substrate for the use of manufacturing an optical bubble switch. The developed equations are found useful for selecting appropriate machining parameters. The ability to use a low-cost CO 2 laser to fabricate microchannels provides an alternative and cost-effective method for prototyping fluid flow channels, chambers and cavities in microfluidic lab chips.

scholarly journals Synchronous fluorescence as a green and selective tool for simultaneous determination of bambuterol and its main degradation product, terbutaline

2018 ◽  
Vol 5 (10) ◽  
pp. 181359 ◽  
Author(s):  
Samah Abo El Abass ◽  
Heba Elmansi
Keyword(s):  
Degradation Product ◽  
Low Cost ◽  
Reference Method ◽  
Cost Effective ◽  
Zero Crossing ◽  
Cost Effective Method ◽  
Validation Parameters ◽  
Main Degradation Product ◽  
20 Nm

A green, sensitive and cost-effective method is introduced in this research for the determination of bambuterol and its main degradation product, terbutaline, simultaneously, relying on the synchronous spectrofluorimetric technique. First derivative synchronous spectrofluorimetric amplitude is measured at Δ λ = 20 nm, so bambuterol can be quantitated at 260 nm, and terbutaline can be measured at 290 nm, each at the zero crossing point of the other. The amplitude–concentration plots were linear over the concentration ranges of 0.2–6.0 µg ml −1 and 0.2–4.0 µg ml −1 for both bambuterol and terbutaline, respectively. Official guidelines were followed to calculate the validation parameters of the proposed method. The low values of limits of detection of 0.023, 0.056 µg ml −1 and limits of quantitation of 0.071, 0.169 µg ml −1 for bambuterol and terbutaline, respectively, point to the sensitivity of the method. Bambuterol is a prodrug for terbutaline, and the latter is considered its degradation product so the established method could be regarded as a stability-indicating one. Moreover, the proposed method was used for the analysis of bambuterol and terbutaline in their single ingredient preparations and the results revealed statistical agreement with the reference method. The suggested method, being a simple and low-cost procedure, is superior to the previously published methods which need more sophisticated techniques, longer analysis time and highly toxic solvents and reagents. It could be considered as an eco-friendly analytical procedure.

Joining Dissimilar Materials Using Friction Stir Scribe Technique

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Piyush Upadhyay ◽  
Yuri Hovanski ◽  
Saumyadeep Jana ◽  
Leonard S. Fifield
Keyword(s):  
Low Cost ◽  
Dissimilar Materials ◽  
Cost Effective ◽  
High Volume ◽  
Industrial Applications ◽  
Critical Pathway ◽  
Friction Stir ◽  
Design Engineers ◽  
Cost Effective Method ◽  
Polymer Metal

Development of a robust and cost-effective method of joining dissimilar materials could provide a critical pathway to enable widespread use of multimaterial designs and components in mainstream industrial applications. The use of multimaterial components such as steel-aluminum and aluminum-polymer would allow design engineers to optimize material utilization based on service requirements and could often lead to weight and cost reductions. However, producing an effective joint between materials with vastly different thermal, microstructural, and deformation responses is highly problematic using conventional joining and/or fastening methods. This is especially challenging in cost sensitive, high volume markets that largely rely on low cost joining solutions. Friction stir scribe (FSS) technology was developed to meet the demands of joining materials with drastically different properties and melting regimes. The process enables joining of light metals like magnesium and aluminum to high temperature materials like steel and titanium. Viable joints between polymer composites and metal can also be made using this method. This paper will present the state of the art, progress made, and challenges associated with this innovative derivative of friction stir welding (FSW) in reference to joining dissimilar metals and polymer/metal combinations.

scholarly journals Phytosynthesis of Palladium Nanoclusters: An Efficient Nanozyme for Ultrasensitive and Selective Detection of Reactive Oxygen Species

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3349
Author(s):  
Ravi Mani Tripathi ◽  
Sang J. Chung
Keyword(s):  
Reactive Oxygen Species ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Reactive Oxygen ◽  
Cost Effective ◽  
Oxygen Species ◽  
Distribution Profile ◽  
Fenton’S Reaction ◽  
Peroxidase Mimetic ◽  
H2o2 Detection

Hydrogen peroxide is a low-reactivity reactive oxygen species (ROS); however, it can easily penetrate cell membranes and produce highly reactive hydroxyl radical species through Fenton’s reaction. Its presence in abnormal amounts can lead to serious diseases in humans. Although the development of a simple, ultrasensitive, and selective method for H2O2 detection is crucial, this remains a strategic challenge. The peroxidase mimetic activity of palladium nanoclusters (PdNCs) has not previously been evaluated. In this study, we developed an ultrasensitive and selective colorimetric detection method for H2O2 using PdNCs. An unprecedented eco-friendly, cost-effective, and facile biological method was developed for the synthesis of PdNCs. This is the first report of the biosynthesis of PdNCs. The synthesized nanoclusters had a significantly narrow size distribution profile and high stability. The nanoclusters were demonstrated to possess a peroxidase mimetic activity that could oxidize peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB). Various interfering substances in serum (100 μM phenylalanine, cysteine, tryptophan, arginine, glucose, urea, Na+, Fe2+, PO43−, Mn+2, Ca2+, Mg2+, Zn2+, NH4+, and K+) were included to evaluate the selectivity of the assay, and oxidation of TMB occurred only in the presence of H2O2. Therefore, PdNCs show an efficient nanozyme for the peroxidase mimetic activity. The assay produced a sufficient signal at the ultralow concentration of 0.0625 µM H2O2. This colorimetric assay provides a real-time, rapid, and easy-to-use platform for the detection of H2O2 for clinical purposes.

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