scholarly journals A Facile Strategy for Immobilizing GOD and HRP onto Pollen Grain and Its Application to Visual Detection of Glucose

2020 ◽  
Vol 21 (24) ◽  
pp. 9529
Author(s):  
Shanxia Jin ◽  
Liping Liu ◽  
Mengying Fan ◽  
Yaru Jia ◽  
Ping Zhou
Keyword(s):  
Visual Detection ◽  
Color Change ◽  
Cost Effective ◽  
Pollen Grain ◽  
Practical Application ◽  
Horse Radish Peroxidase ◽  
Experimental Conditions ◽  
Naked Eye ◽  
Cost Effective Approach ◽  
Affinity Interaction

Pollen grain was explored as a new carrier for enzyme immobilization. After being modified with boric acid-functionalized titania, the pollen grain was able to covalently immobilize glycosylated enzymes by boronate affinity interaction under very mild experimental conditions (e.g., pH 7.0, ambient temperature and free of organic solvent). The glucose oxidase and horse radish peroxidase-immobilized pollen grain became a bienzyme system. The pollen grain also worked as an indicator of the cascade reaction by changing its color. A rapid, simple and cost-effective approach for the visual detection of glucose was then developed. When the glucose concentration exceeded 0.5 mM, the color change was observable by the naked eye. The assay of glucose in body fluid samples exhibited its great potential for practical application.

Visual detection of 8-OHdG based on the aggregation of gold nanoparticles capped with the anti-8-OHdG antibody

2015 ◽  
Vol 7 (19) ◽  
pp. 8360-8365 ◽  
Author(s):  
Liping Wu ◽  
Wendan Pu ◽  
Yue Liu ◽  
Huawen Zhao ◽  
Weiqun Shu
Keyword(s):  
Gold Nanoparticles ◽  
Quantitative Determination ◽  
Rapid Method ◽  
Visual Detection ◽  
Color Change ◽  
Naked Eye ◽  
Absorption Wavelength

AuNPs, capped with anti-8-OHdG antibody, aggregate when 8-OHdG was added, resulting in color change and redshift of absorption wavelength. So a simple and rapid method to selectively determine 8-OHdG was developed and semi-quantitative determination could be achieved by the naked eye.

Microfluidic paper-based analytical device using gold nanoparticles modified with N,N′-bis(2-hydroxyethyl)dithiooxamide for detection of Hg(ii) in air, fish and water samples

2020 ◽  
Vol 44 (43) ◽  
pp. 18662-18667
Author(s):  
Sattar Shariati ◽  
Gholamreza Khayatian
Keyword(s):  
Gold Nanoparticles ◽  
Water Samples ◽  
Visual Detection ◽  
Color Change ◽  
Digital Camera ◽  
New Method ◽  
Naked Eye ◽  
Analytical Device

A new method for visual detection of mercury by color change is developed that can detect Hg2+ by the naked eye or a digital camera.

Highly sensitive and selective “naked eye” sensing of Cu(ii) by a novel amido–imine based receptor: a spectrophotometric and DFT study with practical application

RSC Advances ◽  
2016 ◽  
Vol 6 (34) ◽  
pp. 28194-28199 ◽  
Author(s):  
Arghyadeep Bhattacharyya ◽  
Soumen Ghosh ◽  
Nikhil Guchhait
Keyword(s):  
Aqueous Medium ◽  
Color Change ◽  
Dft Study ◽  
Practical Application ◽  
Naked Eye ◽  
Highly Sensitive

Synthesis of (E)-bis-N'-((1H-pyrrol-2-yl)-methylene)-pyridine-2,6-carbohydrazide and its sensing ability towards copper(ii) ion in aqueous medium by color change, the sensing limit being 4.0 × 10−9 M.

scholarly journals X-ray Visualization and Quantification Using Fibrous Color Dosimeter Based on Leuco Dye

2020 ◽  
Vol 10 (11) ◽  
pp. 3798
Author(s):  
Phu Phong Vo ◽  
Hoan Ngoc Doan ◽  
Kenji Kinashi ◽  
Wataru Sakai ◽  
Naoto Tsutsumi ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Visual Detection ◽  
Color Change ◽  
Fiber Diameter ◽  
Composite Fiber ◽  
Practical Application ◽  
X Ray ◽  
Centrifugal Spinning ◽  
Photoacid Generator

A polystyrene (PS)-based fibrous color dosimeter, comprising a color former based on 2-(phenylamino)-6-(dipentylamino)-3-methylspiro[9H-xanthene-9,3′-phthalide] (Black305) fluoran leuco dye and a 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine (MBTT) photoacid generator, was developed for visual detection of X-ray doses of 15 Gy and higher. The composite fiber was produced by using a centrifugal spinning method, and the obtained composite fiber exhibited a stable and uniform morphology with a fiber diameter of 10 μm or less and had sufficient mechanical strength. As an example of practical application, we successfully processed the composite fiber into an apron and clearly and visually confirmed that the color change from yellow to black occurs on the surface of the fabric under X-ray exposure.

scholarly journals Portable on-chip colorimetric biosensing platform integrated with a smartphone for label/PCR-free detection of Cryptosporidium RNA

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
George S. Luka ◽  
Ephraim Nowak ◽  
Quin Robert Toyata ◽  
Nishat Tasnim ◽  
Homayoun Najjaran ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Color Change ◽  
Colorimetric Assay ◽  
Cost Effective ◽  
Naked Eye ◽  
Sensing Platform ◽  
3D Printed ◽  
Protozoan Pathogen ◽  
On Chip ◽  
Colorimetric Biosensing

AbstractCryptosporidium, a protozoan pathogen, is a leading threat to public health and the economy. Herein, we report the development of a portable, colorimetric biosensing platform for the sensitive, selective and label/PCR-free detection of Cryptosporidium RNA using oligonucleotides modified gold nanoparticles (AuNPs). A pair of specific thiolated oligonucleotides, complementary to adjacent sequences on Cryptosporidium RNA, were attached to AuNPs. The need for expensive laboratory-based equipment was eliminated by performing the colorimetric assay on a micro-fabricated chip in a 3D-printed holder assembly. A smartphone camera was used to capture an image of the color change for quantitative analysis. The detection was based on the aggregation of the gold nanoparticles due to the hybridization between the complementary Cryptosporidium RNA and the oligonucleotides immobilized on the AuNPs surface. In the complementary RNA’s presence, a distinctive color change of the AuNPs (from red to blue) was observed by the naked eye. However, in the presence of non-complementary RNA, no color change was observed. The sensing platform showed wide linear responses between 5 and 100 µM with a low detection limit of 5 µM of Cryptosporidium RNA. Additionally, the sensor developed here can provide information about different Cryptosporidium species present in water resources. This cost-effective, easy-to-use, portable and smartphone integrated on-chip colorimetric biosensor has great potential to be used for real-time and portable POC pathogen monitoring and molecular diagnostics.

scholarly journals A Field-Deployable Diagnostic Assay for the Visual Detection of Misfolded Prions

2021 ◽  
Author(s):  
Peter R Christenson ◽  
Manci Li ◽  
Gage Rowden ◽  
Marc Schwabenlander ◽  
Tiffany M Wolf ◽  
...  
Keyword(s):  
Protein Misfolding ◽  
Visual Detection ◽  
Color Change ◽  
Cost Effective ◽  
Diagnostic Techniques ◽  
Diagnostic Tools ◽  
Laboratory Equipment ◽  
Field Station ◽  
Misfolding Diseases ◽  
Light Absorbance

Diagnostic tools for the detection of protein-misfolding diseases (i.e., proteopathies) are limited. Gold nanoparticles (AuNPs) facilitate sensitive diagnostic techniques via visual color change for the detection of a variety of targets. In parallel, recently developed quaking-induced conversion (QuIC) assays leverage protein-amplification and fluorescent signaling for the accurate detection of misfolded proteins. Here, we combine AuNP and QuIC technologies for the visual detection of amplified misfolded prion proteins from tissues of wild white-tailed deer infected with chronic wasting disease (CWD), a prion disease of cervids. Our newly developed assay, MN-QuIC™, enables both naked-eye and light-absorbance measurements for detection of misfolded prions. MN-QuIC™ leverages basic laboratory equipment that is cost-effective and portable, thus facilitating real-time prion diagnostics across a variety of settings. To test the portability of our assay, we deployed to a rural field-station in southeastern Minnesota and tested for CWD on site. We successfully demonstrated that MN-QuIC™ is functional in a non-traditional laboratory setting by performing a blinded analysis in the field and correctly identifying all CWD positive and CWD not detected deer at the field site in less than 24 hours, thus documenting the portability of the assay. Additionally, we show that electrostatic forces help govern the AuNP/prion interactions. Importantly, all of our white-tailed deer (n=37) were independently tested using ELISA, IHC, and/or RT-QuIC technologies and results secured with MN-QuIC™ were 100% consistent with these tests. We conclude that hybrid AuNP and QuIC assays, such as MN-QuIC™, have great potential for sensitive, field-deployable diagnostics of a variety of protein misfolding diseases.

Preparation of PAA/WO3 composite films with enhanced electrochromism via layer-by-layer method

2018 ◽  
Vol 25 (3) ◽  
pp. 565-569
Author(s):  
Na Xu ◽  
Xiaodong Shen ◽  
Sheng Cui ◽  
Xibin Yi
Keyword(s):  
Composite Film ◽  
Color Change ◽  
Composite Films ◽  
Cost Effective ◽  
Electrochromic Property ◽  
Cyclic Voltammogram ◽  
Layer By Layer ◽  
High Porosity ◽  
Layer Method ◽  
Cost Effective Approach

Abstract The polyacrylic acid/tungsten oxide (PAA/WO3) composite films with good electrochromic properties have been prepared by a layer-by-layer method. The porous PAA layers were used as a template for the deposition of WO3, and finally, the composite film showed a network structure with high porosity. The electrochromic performance of the PAA/WO3 composite film was investigated by means of cyclic voltammogram (CV), chronoamperometry (CA), and transmittance measurements. The PAA/WO3 film also exhibited a remarkable electrochromism ability with the reversible color change from transparent colorless to dark blue and the transmittance change from 83% to 24% at 620 nm. This research provided a cost-effective approach for the preparation of PAA/WO3 composite films with controllable microstructure and good electrochromic property.

scholarly journals Metabolic activity of an anammox population affected by major environmental factors

2021 ◽  
Vol 293 ◽  
pp. 01027
Author(s):  
Yifu Rao ◽  
Jia Meng ◽  
Yajie Tian ◽  
Jianzheng Li
Keyword(s):  
Environmental Factors ◽  
Enrichment Culture ◽  
Research Work ◽  
Granular Sludge ◽  
Cost Effective ◽  
Practical Application ◽  
Key Indicator ◽  
Cost Effective Approach ◽  
Anammox Activity ◽  
Anammox Process

Anammox is known as a cost-effective approach to nitrogen removal from ammonium-rich wastewater. However, the eco-physiological characteristics of anammox population have not well been understood so far, which has obstructed the practical application of anammox process. In the present research work, an enrichment culture of anammox population was collected from an expanded granular sludge bed (EGSB) reactor, and the anammox activity was evaluated by various pH, temperature and reactant density, progressively. The results showed that the optimal ecological amplitude of pH and temperature for the anammox population was ranged from 7.0-7.5 and 30°C-35°C, respectively. To make anammox process more efficient, the density of NH4+-N and NO2−-N should be around 10.0 and 4.0 mmol·L−1, respectively. It was found that anammox population was more sensitive to NO2−-N density than NH4+-N density, and then NO2−-N density was proposed as a key indicator to practicing anammox process in engineering. With the findings, the present research will be significant in practicing annamox process.

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