scholarly journals Rapid One-Step Plasma Test for the Electrochemical and Colorimetric Detection of a Universal Cancer Biomarker

2019 ◽  
Vol 65 (7) ◽  
pp. 824-826
Author(s):  
Jae-Seung Lee
Keyword(s):  
Colorimetric Detection ◽  
Cancer Biomarker ◽  
One Step

Spinel Zn3V3O8 nanosheets via one - step hydrothermal synthesis with peroxidase-like activity for high-sensitive glucose colorimetric detection in synthetic perspiration

2021 ◽  
Author(s):  
Guizeng Yang ◽  
Yi Lu ◽  
Yi Li ◽  
Meihui Ying ◽  
Haibo Pan ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Spinel Structure ◽  
Colorimetric Detection ◽  
Ternary Oxide ◽  
Exposed Surface ◽  
Catalytic Sites ◽  
One Step

Due to the specific spinel structure, ternary oxide with multi-catalytic sites at high-active exposed surface is recommended to an alternative bio-catalyst. Spinel zinc vanadate with two- dimentional nanosheets (Zn3V3O8 NSs)...

Preparation of porphyrin modified CO9S8 nanocomposites and application for colorimetric biosensing of H2O2

2018 ◽  
Vol 22 (09n10) ◽  
pp. 935-943 ◽  
Author(s):  
Yan Gao ◽  
Chunqiao Jin ◽  
Miaomiao Chen ◽  
Xixi Zhu ◽  
Min Fu ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Catalytic Activity ◽  
Peroxidase Activity ◽  
Catalytic Mechanism ◽  
Color Change ◽  
Colorimetric Detection ◽  
Buffer Solution ◽  
Hydrogen Peroxide Detection ◽  
Steady State Kinetics ◽  
One Step

Hydrogen peroxide detection has been widely applied in the fields of biology, medicine, and chemistry. Colorimetric detection of hydrogen peroxide has proven to be a fast and convenient method. In this work, 5,10,15,20-tetrakis(4-chlorophenyl) porphyrin modified Co[Formula: see text]S[Formula: see text] nanocomposites (H[Formula: see text]TClPP-Co[Formula: see text]S[Formula: see text] were prepared via a facile one-step hydrothermal method. H[Formula: see text]TClPP-Co[Formula: see text]S[Formula: see text] nanocomposites were demonstrated to possess an enhanced mimetic peroxidase activity toward the substrate, 3,3[Formula: see text],5,5[Formula: see text]-tetramethylbenzidine (TMB), which can be oxidized to oxTMB (oxidized TMB) in a buffer solution of hydrogen peroxide with a color change from colorless to blue. The catalytic activity of H[Formula: see text]TClPP-Co[Formula: see text]S[Formula: see text] was further analyzed by steady-state kinetics, and H[Formula: see text]TClPP-Co[Formula: see text]S[Formula: see text] had high affinity towards both TMB and H[Formula: see text]O[Formula: see text]. Furthermore, fluorescence and ESR data revealed that the catalytic mechanism of the peroxidase activity of H[Formula: see text]TClPP-Co[Formula: see text]S[Formula: see text] is due to hydroxyl radicals generated from decomposition of H[Formula: see text]O[Formula: see text]. Based on the catalytic activity of H[Formula: see text]TClPP-Co[Formula: see text]S[Formula: see text], a sensitive colorimetric sensor of H[Formula: see text]O[Formula: see text] with a detection limit of 6.803 [Formula: see text]M as well as a range of 7–100 [Formula: see text]M was designed.

scholarly journals One-Step Hydrothermal Synthesis of N, Fe-Codoped Carbon Dots as Mimic Peroxidase and Application on Hydrogen Peroxide and Glucose Detection

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yan Li ◽  
Yuhui Weng ◽  
Shikong Lu ◽  
Meihua Xue ◽  
Bixia Yao ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
Color Change ◽  
Limit Of Detection ◽  
Colorimetric Detection ◽  
Catalytic Efficiency ◽  
Transmission Electron ◽  
One Step ◽  
First Time

In this paper, N, Fe-codoped carbon dots (N, Fe-CDs) were synthesized from β-cyclodextrin, ethylenediamine, and ferric chloride for the first time using a convenient one-step hydrothermal method. The obtained N, Fe-CDs were characterized by various methods including transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The N, Fe-CDs exhibited better catalytic activity than horseradish peroxidase (HRP) and caused an evident color change for 3,3′,5,5′-tetramethylbenzidine in the presence of H2O2. Kinetic experiments show that the apparent Km value for the N, Fe-CDs with TMB (0.40 mM) or H2O2 (0.35 mM) as the substrate was lower than that of HRP (0.43 and 3.70 mM), suggesting that the N, Fe-CDs have a much higher affinity for TMB and H2O2 than HRP. The Km/Vmax value for the N, Fe-CDs (21.74×103·s for H2O2) is significantly lower than that for HRP (42.53×103·s), suggesting that the N, Fe-CDs have a stronger catalytic efficiency for H2O2 than HRP. Furthermore, a highly efficient and sensitive colorimetric detection method for glucose was developed using the N, Fe-CDs as mimic peroxidase to detect the hydrogen peroxide generated by the oxidation of glucose by glucose oxidase. The limit of detection for H2O2 and glucose was found to be 0.52 and 3.0 μM, respectively. The obtained N, Fe-codoped carbon dots, which possess simulated peroxidase activity, can potentially be used in the field of biotechnology.

scholarly journals One-Step Polylactic Acid Screen-Printing Microfluidic Paper-Based Analytical Device: Application for Simultaneous Detection of Nitrite and Nitrate in Food Samples

Chemosensors ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 44 ◽  
Author(s):  
Siriwan Teepoo ◽  
Supattra Arsawiset ◽  
Pitchayatida Chanayota
Keyword(s):  
Polylactic Acid ◽  
Screen Printing ◽  
Colorimetric Detection ◽  
Simultaneous Detection ◽  
Reference Method ◽  
Cost Effective ◽  
Food Samples ◽  
Device Fabrication ◽  
Experimental Conditions ◽  
One Step

In this work, we report a one-step approach for fabricating screened-printed microfluidic paper-based analytical devices (μPADs) using polylactic acid as a new hydrophobic material. A polylactic acid solution was screen printed onto chromatography papers to create hydrophobic patterns for fluidic channels. The optimal polylactic acid concentration for successful device fabrication is 9% w/v. The μPADs were fabricated within 2 min and provided high reproducibility and stability. The utility of polylactic acid screen-printing was demonstrated for the simultaneous detection of nitrite and nitrate using colorimetric detection. Under optimized experimental conditions, the detection limits and the linear ranges, respectively, were 1.2 mg L−1 and 2–10 mg L−1 for nitrite and 3.6 mg L−1 and 10–50 mg L−1 for nitrate. The detection times for both ions were found to be within 12 min. The developed μPAD was applied for the simultaneous determination of these ions in food samples, and no significant differences in the analytical results were observed compared to those of the reference method. The polylactic acid screen-printing approach presented here provides a simple, rapid, and cost-effective alternative fabrication method for fabricating μPADs.

One-step colorimetric detection of an antibody based on protein-induced unfolding of a G-quadruplex switch

2017 ◽  
Vol 53 (34) ◽  
pp. 4692-4694 ◽  
Author(s):  
Xiaolu Hu ◽  
Chao Li ◽  
Chang Feng ◽  
Xiaoxia Mao ◽  
Yang Xiang ◽  
...  
Keyword(s):  
Protein Binding ◽  
Colorimetric Assay ◽  
Colorimetric Detection ◽  
Conformational Switching ◽  
Switching Strategy ◽  
G Quadruplex ◽  
One Step

A colorimetric assay for an antibody is developed by combining a protein binding-induced signaling approach with a DNAzyme-based conformational switching strategy.

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