scholarly journals Amperometric Detection ofBacillus anthracisSpores: A Portable, Low-Cost Approach to the ELISA

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Gabriel D. Peckham ◽  
Brian E. Hew ◽  
David F. Waller ◽  
Charlie Holdaway ◽  
Michael Jen
Keyword(s):  
Glucose Oxidase ◽  
Magnetic Beads ◽  
Low Cost ◽  
Amperometric Detection ◽  
Signal Generation ◽  
Quantitative Detection ◽  
Laptop Computer ◽  
Electron Mediator ◽  
Fluorescent Signal ◽  
Flow Devices

Antibody-based detection assays are generally robust, a desirable characteristic for in-the-field use. However, to quantify the colorimetric or fluorescent signal, these assays require expensive and fragile instruments which are ill-suited to in-the-field use. Lateral flow devices (LFDs) circumvent these barriers to portability but suffer from poor sensitivity and subjective interpretation. Here, an antibody-based method for detectingBacillus anthracisspores via amperometric signal generation is compared to ELISA and LFDs. This amperometric immunoassay uses antibody conjugated to magnetic beads and glucose oxidase (GOX) along with the electron mediator 2, 6-dichlorophenolindophenol (DCPIP) for production of a measurable current from a 0.4 V bias voltage. With similar sensitivity to ELISA, the assay can be completed in about 75 minutes while being completely powered and operated from a laptop computer. Immunoassay amperometry holds promise for bringing low-cost, quantitative detection of hazardous agents to the field.

Visual detection of glucose based on quantum dots aerogel in microfluidic chips

2018 ◽  
Vol 10 (48) ◽  
pp. 5749-5754 ◽  
Author(s):  
Tao Hu ◽  
Yi Ye ◽  
Ke Chen ◽  
Feifei Long ◽  
Wen Sang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Glucose Oxidase ◽  
Human Urine ◽  
Visual Detection ◽  
Low Cost ◽  
Quantitative Detection ◽  
Microfluidic Chips ◽  
Human Urine And Serum ◽  
Urine And Serum

In this study, we demonstrated a new optical glucose microfluidic sensor based on quantum dots (QDs) aerogels and glucose oxidase (GOx) for rapid, low-cost and quantitative detection of glucose in human urine and serum.

Fast Screening for Antioxidant Properties of Flavonoids from Pterogyne nitens Using Electrochemical Methods

2012 ◽  
Vol 95 (3) ◽  
pp. 773-777 ◽  
Author(s):  
Leonardo Luiz Okumura ◽  
Luis Octávio Regasini Regasini ◽  
Daniara Cristina Fernandes ◽  
Dulce Helena Siqueira da Silva ◽  
Maria Valnice Boldrin Zanoni ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Low Cost ◽  
Supporting Electrolyte ◽  
Antioxidant Properties ◽  
Reference Electrode ◽  
Structural Features ◽  
Quantitative Detection ◽  
Nonaqueous Media ◽  
Electrochemical Detector ◽  
Fast Screening

Abstract A fast, low-cost, convenient, and especially sensitive voltammetric screening approach for the study of the antioxidant properties of isoquercitrin and pedalitin from Pterogyne nitens is suggested in this work. These flavonoids were investigated for their redox properties using cyclic voltammetry in nonaqueous media using N,N-dimethylformamide and tetrabutylammonium tetrafluorborate as the supporting electrolyte, a glassy carbon working electrode, Ag|AgCl reference electrode, and Pt bare wire counter electrode. The comparative analysis of the activity of rutin has also been carried out. Moreover, combining HPLC with an electrochemical detector allowed qualitative and quantitative detection of micromolecules (e.g., isoquercitrin and pedalitin) that showed antioxidant activities. These results were then correlated to the inhibition of β-carotene bleaching determined by TLC autographic assay and to structural features of the flavonoids.

Squamous cell carcinoma DNA detection using ultrabright SERS nanorattles and magnetic beads for head and neck cancer molecular diagnostics

2017 ◽  
Vol 9 (37) ◽  
pp. 5550-5556 ◽  
Author(s):  
P. Vohra ◽  
H. T. Ngo ◽  
W. T. Lee ◽  
T. Vo-Dinh
Keyword(s):  
Squamous Cell Carcinoma ◽  
Head And Neck Cancer ◽  
Cell Carcinoma ◽  
Head And Neck ◽  
Molecular Diagnostics ◽  
Neck Cancer ◽  
Squamous Cell ◽  
Magnetic Beads ◽  
Low Cost ◽  
Diagnostic Technologies

A rise in head and neck cancers in low and middle countries over recent years has prompted the need for low-cost, resource-efficient diagnostic technologies.

scholarly journals A novel method for rapid and quantitative detection of bisphenol A in urine

2020 ◽  
Author(s):  
Aleksandra Rutkowska ◽  
Aleksandra Olsson ◽  
Jacek Namieśnik ◽  
Andrzej Milewicz ◽  
Jan Krzysztof Ludwicki ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Human Exposure ◽  
Hormone Receptors ◽  
Low Cost ◽  
Medical Diagnostics ◽  
Quantitative Detection ◽  
Adverse Health Effects ◽  
Increased Risk ◽  
Novel Method ◽  
Lifestyle Diseases

Bisphenol A (BPA) is classified as an endocrine disruptor (ED) and it can interact with variety of hormone receptors leading to hormonal disruption and increased risk of various adverse health effects. Reducing human exposure to BPA is one of the main challenges of public health, as it is constantly present in daily life. A low-cost and commonly applied method to enable determination of BPA in the patient's body has yet to be developed. Currently available techniques are expensive, time-consuming, and require access to highly equipped analytical chemistry laboratories. Here we describe a fast and cheap engineered lateral flow assay of our design, to detect of BPA in urine samples. The technology not only provides an opportunity to perform rapid medical diagnostics without the need for an access to the central laboratory but also a means for self-diagnosis by the patient. The addition of β-glucuronidase improves the sensitivity of detection as it releases the free BPA from glucuronide complexes in urine. This invention may become a demonstrated analytical means for lowering human exposure to BPA and probably also to other EDs and consequently, may be useful in decrease of the risk for several lifestyle diseases.

Application of a Low-cost Optical Tweezers Setup in Fluorescence Quantitative Detection

Daxue Huaxue ◽  
2015 ◽  
Vol 30 (2) ◽  
pp. 50-55
Author(s):  
Tang Hongwu ◽  
◽  
◽  
Cao Di ◽  
Li Chengyu ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Low Cost ◽  
Quantitative Detection

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 A Self-Powered Biosensor for the Detection of Glutathione

Biosensors ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 114 ◽  
Author(s):  
Brandon G. Roy ◽  
Julia L. Rutherford ◽  
Anna E. Weaver ◽  
Kevin Beaver ◽  
Michelle Rasmussen
Keyword(s):  
Detection Limit ◽  
Glucose Oxidase ◽  
Power Output ◽  
Low Cost ◽  
Linear Range ◽  
Biofuel Cell ◽  
Bilirubin Oxidase ◽  
Biological Molecule ◽  
Enzymatic Biofuel Cell ◽  
Self Powered

Glutathione is an important biological molecule which can be an indicator of numerous diseases. A method for self-powered detection of glutathione levels in solution has been developed using an enzymatic biofuel cell. The device consists of a glucose oxidase anode and a bilirubin oxidase cathode. For the detection of glutathione, the inhibition of bilirubin oxidase leads to a measurable decrease in current and power output. The reported method has a detection limit of 0.043 mM and a linear range up to 1.7 mM. Being able to detect a range of concentrations can be useful in evaluating a patient’s health. This method has the potential to be implemented as a quick, low-cost alternative to previously reported methods.

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).

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