scholarly journals Dual-Modal Assay Kit for the Qualitative and Quantitative Determination of the Total Water Hardness Using a Permanent Marker Fabricated Microfluidic Paper-Based Analytical Device

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Oyejide Damilola Oyewunmi ◽  
Seyed Hamid Safiabadi-Tali ◽  
Sana Jahanshahi-Anbuhi
Keyword(s):  
Ethylenediaminetetraacetic Acid ◽  
Limit Of Detection ◽  
Low Cost ◽  
Water Hardness ◽  
Sample Introduction ◽  
World Health ◽  
Total Hardness ◽  
Quantitative Detection ◽  
Qualitative And Quantitative ◽  
Analytical Device

A dip-and-read microfluidic paper-based analytical device (µPAD) was developed for the qualitative and quantitative detection of the total hardness of water. To create well-defined hydrophobic barriers on filter paper, a regular office printer and a commercially available permanent marker pen were utilized as a quick and simple technique with easily accessible equipment/materials to fabricate µPAD in new or resource-limited laboratories without sophisticated equipment. After a wettability and barrier efficiency analysis on the permanent marker colors, the blue and green ink markers exhibited favorable hydrophobic properties and were utilized in the fabrication of the developed test devices. The device had five reaction and detection zones modeled after the classification given by the World Health Organization (WHO), so qualitatively it determined whether the water was ‘soft’, ‘moderately hard’, ‘hard’, or ‘very hard’ by changing color from blue to pink in about 3 min. The device was also used to introduce an alternative colorimetric reaction for quantitative analysis of the water hardness without the need for ethylenediaminetetraacetic acid (EDTA) and without compromising the simplicity and low cost of the device. The developed µPAD showed a calculated limit of detection (LOD) of 0.02 mM, which is at least 80% less than those of commercially available test strips and other reported µPADs, and the results of the real-world samples were consistent with those of the standard titration (with EDTA). In addition, the device exhibited stability for 2 months at room and frigid condition (4 °C) and at varying harsh temperatures from 25 to 100 °C. The results demonstrate that the developed paper-based device can be used for rapid, on-site analysis of water with no interferences and no need for a pipette for sample introduction during testing.

scholarly journals Optimized qRT-PCR Approach for the Detection of Intra- and Extra-Cellular SARS-CoV-2 RNAs

2020 ◽  
Vol 21 (12) ◽  
pp. 4396 ◽  
Author(s):  
Tuna Toptan ◽  
Sebastian Hoehl ◽  
Sandra Westhaus ◽  
Denisa Bojkova ◽  
Annemarie Berger ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
World Health ◽  
Quantitative Detection ◽  
Rt Pcr ◽  
M Gene ◽  
Control And Prevention ◽  
Pcr Assays ◽  
Novel Coronavirus ◽  
Health Organization

The novel coronavirus SARS-CoV-2 is the causative agent of the acute respiratory disease COVID-19, which has become a global concern due to its rapid spread. Meanwhile, increased demand for testing has led to a shortage of reagents and supplies and compromised the performance of diagnostic laboratories in many countries. Both the World Health Organization (WHO) and the Center for Disease Control and Prevention (CDC) recommend multi-step RT-PCR assays using multiple primer and probe pairs, which might complicate the interpretation of the test results, especially for borderline cases. In this study, we describe an alternative RT-PCR approach for the detection of SARS-CoV-2 RNA that can be used for the probe-based detection of clinical isolates in diagnostics as well as in research labs using a low-cost SYBR green method. For the evaluation, we used samples from patients with confirmed SARS-CoV-2 infections and performed RT-PCR assays along with successive dilutions of RNA standards to determine the limit of detection. We identified an M-gene binding primer and probe pair highly suitable for the quantitative detection of SARS-CoV-2 RNA for diagnostic and research purposes.

scholarly journals Optimized qRT-PCR approach for the detection of intra- and extra-cellular SARS-CoV-2 RNAs

2020 ◽  
Author(s):  
Tuna Toptan ◽  
Sebastian Hoehl ◽  
Sandra Westhaus ◽  
Denisa Bojkova ◽  
Annemarie Berger ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
World Health ◽  
Quantitative Detection ◽  
Rt Pcr ◽  
M Gene ◽  
Control And Prevention ◽  
Pcr Assays ◽  
Novel Coronavirus ◽  
Health Organization

AbstractThe novel coronavirus SARS-CoV-2 is the causative agent of the acute respiratory disease COVID-19 which has become a global concern due to its rapid spread. Meanwhile, increased demand in testing has led to shortage of reagents, supplies, and compromised the performance of diagnostic laboratories in many countries. Both the world health organization (WHO) and the Center for Disease Control and Prevention (CDC) recommend multi-step RT-PCR assays using multiple primer and probe pairs, which might complicate interpretation of the test results especially for borderline cases. In this study, we describe an alternative RT-PCR approach for the detection of SARS-CoV-2 RNA that can be used for the probe-based detection of clinical isolates in the diagnostics as well as in research labs using a low cost SYBR green method. For the evaluation, we used samples from patients with confirmed SARS-CoV-2 infection and performed RT-PCR assays along with successive dilutions of RNA standards to determine the limit of detection. We identified an M-gene binding primer and probe pair highly suitable for quantitative detection of SARS-CoV-2 RNA for diagnostic and research purposes.

scholarly journals Disposable silicon-based all-in-one micro-qPCR for rapid on-site detection of pathogens

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Estefania Nunez-Bajo ◽  
Alexander Silva Pinto Collins ◽  
Michael Kasimatis ◽  
Yasin Cotur ◽  
Tarek Asfour ◽  
...  
Keyword(s):  
Real Time ◽  
Limit Of Detection ◽  
Low Cost ◽  
High Specificity ◽  
Rapid Screening ◽  
Quantitative Detection ◽  
The Novel ◽  
Novel Coronavirus ◽  
Silicon Based ◽  
Specific Sequences

AbstractRapid screening and low-cost diagnosis play a crucial role in choosing the correct course of intervention when dealing with highly infectious pathogens. This is especially important if the disease-causing agent has no effective treatment, such as the novel coronavirus SARS-CoV-2, and shows no or similar symptoms to other common infections. Here, we report a disposable silicon-based integrated Point-of-Need transducer (TriSilix) for real-time quantitative detection of pathogen-specific sequences of nucleic acids. TriSilix can be produced at wafer-scale in a standard laboratory (37 chips of 10 × 10 × 0.65 mm in size can be produced in 7 h, costing ~0.35 USD per device). We are able to quantitatively detect a 563 bp fragment of genomic DNA of Mycobacterium avium subspecies paratuberculosis through real-time PCR with a limit-of-detection of 20 fg, equivalent to a single bacterium, at the 35th cycle. Using TriSilix, we also detect the cDNA from SARS-CoV-2 (1 pg) with high specificity against SARS-CoV (2003).

scholarly journals Highly Selective, Aptamer-Based, Ultrasensitive Nanogold Colorimetric Smartphone Readout for Detection of Cd(II)

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2745 ◽  
Author(s):  
Lu Xu ◽  
Jun Liang ◽  
Yonghui Wang ◽  
Shuyue Ren ◽  
Jin Wu ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
Quantitative Detection ◽  
Practical Application ◽  
Full Agreement ◽  
Experimental Conditions ◽  
Dose Time ◽  
Dimethyl Ammonium ◽  
Rice Samples ◽  
Optimized Conditions

A highly selective and sensitive method for Cd(II) detection was developed based on aptamer and gold nanoparticles (AuNPs) combined with a colorimetric smartphone readout. The experimental conditions such as reaction time of polydiene dimethyl ammonium chloride (PDDA) and AuNPs, PDDA dose, time of aptamer and PDDA incubation, and aptamer concentration were optimized. Under the optimized conditions, the color and red(R) value of the solution was concentration-dependent on Cd(II). The proposed method exhibited a linear range of 1–400 ng/mL (r2 = 0.9794) with a limit of detection (LOD) of 1 ng/mL. This method had been successfully applied to test and quantify Cd(II) in water and rice samples, and the results were in full agreement with those from the atomic absorption spectrometer. Therefore, low-cost colorimetry demonstrated its potential for practical application in visual or quantitative detection with a smartphone. This approach can be readily applied to other analytes.

Dip-Type Paper-Based Analytical Device for Straightforward Quantitative Detection without Precise Sample Introduction

ACS Sensors ◽  
2021 ◽  
Author(s):  
Takeshi Komatsu ◽  
Ryoga Maeda ◽  
Masatoshi Maeki ◽  
Akihiko Ishida ◽  
Hirofumi Tani ◽  
...  
Keyword(s):  
Sample Introduction ◽  
Quantitative Detection ◽  
Analytical Device

scholarly journals Characterization of handmade Nepali paper as a platform for paper analytical device to determine anti-diabetic drug

2021 ◽  
Author(s):  
Ram Bhattarai ◽  
Sanam Pudasaini ◽  
Mukesh Sah ◽  
Bhanu Neupane ◽  
Basant Giri
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
Water Contact ◽  
Regulatory Standards ◽  
Three Samples ◽  
Limit Of Quantitation ◽  
Metformin Concentration ◽  
Analytical Device

The COVID-19 pandemic has highlighted the need of eco-friendly and locally or distributed manufacturing of diagnostic and safety products. Here, we characterized five handmade papers for their potential application to make paper analytical device (PADs). The handmade papers were made from locally available plant fiber using eco-friendly method. Thickness, grammage, and apparent density of the paper samples ranged from 198 μm to 314 μm, 49 g/m2 to 117.8 g/m2, and 0.23 to 0.39 g/cm3, respectively. Moisture content, water filtration and wicking speed ranged from 5.2% to 7.1%, 35.7 to 156.7, and 0.062 to 0.124 mms-1, respectively. Further, water contact angle and porosity ranged from 76˚ to 112˚ and 79% to 83%, respectively. The best paper sample one was chosen to fabricate PADs which were used for the determination of metformin. The metformin assay on PADs followed linear range from 0.0625 to 0.5 mg/mL. The assay had limit of detection and limit of quantitation of 0.05 mg/mL and 0.18 mg/mL respectively. The new method was used to test metformin samples (n=20) collected from local pharmacies. The average amount of metformin concentration in samples was 465.6 ± 15.1mg/tablet. Three samples did not meet the regulatory standards. When compared with spectrophotometric method, PADs assay correctly predicted 18 out of 20 samples. The PADs assay on handmade paper may provide a low-cost and easy-to-use system to screening the quality of drugs and other point-of-need applications.

scholarly journals Electrochemical micro analytical device interfaced with portable potentiostat for rapid detection of chlorpyrifos using acetylcholinesterase conjugated metal organic framework using Internet of things

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shalini Nagabooshanam ◽  
Souradeep Roy ◽  
Ashish Mathur ◽  
Irani Mukherjee ◽  
Satheesh Krishnamurthy ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Low Cost ◽  
Metal Organic Framework ◽  
Electrochemical Techniques ◽  
Electrochemical Analysis ◽  
Vegetable Sample ◽  
Metal Organic ◽  
Analytical Device ◽  
Organic Framework

AbstractAn Electrochemical micro Analytical Device (EµAD) was fabricated for sensitive detection of organophosphate pesticide chlorpyrifos in the food chain. Gold microelectrode (µE) modified with Zinc based Metal Organic Framework (MOF-Basolite Z1200) and Acetylcholinesterase (AChE) enzyme served as an excellent electro-analytical transducer for the detection of chlorpyrifos. Electrochemical techniques such as Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) and Differential Pulse Voltammetry (DPV) were performed for electrochemical analysis of the developed EµAD. The sensor needs only 2 µL of the analyte and it was tested within the linear range of 10 to 100 ng/L. The developed EµAD’s limit of detection (LoD) and sensitivity is 6 ng/L and 0.598 µ A/ng L−1/mm2 respectively. The applicability of the device for the detection of chlorpyrifos from the real vegetable sample was also tested within the range specified. The fabricated sensor showed good stability with a shelf-life of 20 days. The EµAD’s response time is of 50 s, including an incubation time of 20 s. The developed EµAD was also integrated with commercially available low-cost, handheld potentiostat (k-Stat) using Bluetooth and the results were comparable with a standard electrochemical workstation.

Paper-Based Analytical Device for Rapid Naked-Eye Detection of Sulfide in Water Samples

2020 ◽  
Vol 42 (5) ◽  
pp. 696-696
Author(s):  
Lingzhi Zhao Lingzhi Zhao
Keyword(s):  
Water Samples ◽  
Limit Of Detection ◽  
Rapid Determination ◽  
Tap Water ◽  
Low Cost ◽  
Color Intensity ◽  
Detection Zone ◽  
Simulated Waste ◽  
Optimized Conditions ◽  
Analytical Device

This paper describes the development of a low-cost paper-based colorimetric analytical device for the accurate and rapid determination of sulfide. Under optimized conditions, Na2S was dropped in the uptake zone I and the probe in the uptake zone II, they converged to the detection zone via capillary force and formed an intense pink resorufin. Sulfide can be quantified based on the average color intensity values of the product “free resorufin”. The color intensity is recorded using a camera phone, and quantification was made using Adobe Photoshop. The as-developed analytical device detected sulfide in the range of 5–400 μM (R2 = 0.982) with the limit of detection (LOD) 1 μM, and was successfully applied in sulfide assay in spiked water samples including tap water and simulated waste water. Colorimetric results from the proposed paper-based colorimetric analytical device were consistent with that from methylene blue (MB) method.

scholarly journals Smartphone-Based Microfluidic Colorimetric Sensor for Gaseous Formaldehyde Determination with High Sensitivity and Selectivity

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3141 ◽  
Author(s):  
Xiao-Liang Guo ◽  
Yan Chen ◽  
Hong-Lan Jiang ◽  
Xian-Bo Qiu ◽  
Du-Li Yu
Keyword(s):  
Microfluidic Chip ◽  
Limit Of Detection ◽  
Low Cost ◽  
Sick Building Syndrome ◽  
High Sensitivity ◽  
Colorimetric Sensor ◽  
World Health ◽  
Formaldehyde Determination ◽  
Sensitivity And Selectivity ◽  
Gaseous Formaldehyde

Formaldehyde is one of the most dangerous air pollutants, which can cause sick building syndrome. Thus, it is very crucial to precisely determine formaldehyde with a low cost and simple operation. In this paper, a smartphone-based microfluidic colorimetric sensor is devised for gaseous formaldehyde determination with high sensitivity and selectivity. Specifically, a novel microfluidic chip is proposed based on the 4-aminohydrazine-5-mercapto-1,2,4-triazole (AHMT) method to determine formaldehyde; the chip consists of two reagent reservoirs, one reaction reservoir and a mixing column. In this design to prevent the fluid from flowing out while letting the gas molecule in, a hydrophobic porous poly tetra fluoroethylene (PTFE) membrane is put on the top of the reaction reservoir. Using the microfluidic chip sensor, a smartphone-based formaldehyde determination system is developed, which makes the measuring process automated and simple. As per the experiment results, the limit-of-detection (LOD) of the system is as low as 0.01 ppm, which is much lower than the maximum exposure concentration (0.08 ppm) recommended by the World Health Organization (WHO). Moreover, the sensor is hardly affected by acetaldehyde, volatile organic compounds (VOCs) or acidic-alkaline, which shows great selectivity. Finally, the performance of the proposed sensor is verified by using it for the determination of formaldehyde in a newly decorated house.

Fusion of a Low-cost Electronic Nose and Near Infrared Spectroscopy for Qualitative and Quantitative Detection of Beef Adulterated with Duck

2022 ◽  
Author(s):  
FangKai Han ◽  
Xingyi Huang ◽  
Joshua Harington Aheto ◽  
Xiaorui Zhang ◽  
Marwan M.A. Rashed
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Electronic Nose ◽  
Near Infrared ◽  
Low Cost ◽  
Nir Spectroscopy ◽  
Quantitative Detection ◽  
Qualitative And Quantitative ◽  
Convenient Technique ◽  
Colorimetric Sensors

A low-cost electronic nose (E-nose) based on colorimetric sensors fused with near-infrared (NIR) spectroscopy was proposed as a rapid and convenient technique for detecting beef adulterated with duck. The total...

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