scholarly journals One-Step and Colorimetric Detection of Fish Freshness Indicator Hypoxanthine Based on the Peroxidase Activity of Xanthine Oxidase Grade I Ammonium Sulfate Suspension

2021 ◽  
Vol 12 ◽  
Author(s):  
Chen Guo ◽  
Shuhan You ◽  
Changmei Li ◽  
Tiantian Chen ◽  
Xiudan Wang
Keyword(s):  
Xanthine Oxidase ◽  
Ammonium Sulfate ◽  
Peroxidase Activity ◽  
Colorimetric Detection ◽  
Reaction System ◽  
Sea Bass ◽  
Fish Samples ◽  
One Step ◽  
Color Reactions ◽  
Short Time

The global food waste problem, especially aquatic product spoilage, stimulates the accurate freshness analysis of food products. However, it still remains a great challenge to realize in-field determination of fish freshness at the time of use. In the present study, a colorimetric enzyme biosensor was developed for one-step detection of hypoxanthine (Hx), which is an important intermediate of adenosine triphosphate decomposition during fish storage. We demonstrate that xanthine oxidase grade I ammonium sulfate suspension (XOD-ASS) possesses peroxidase activity. It can oxidize different peroxidase substrates, including 3,3′,5,5′-tetramethylbenzidine, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, and o-phenylenediamine in the presence of H2O2, producing visible color reactions. Further experiments indicate that XOD-ASS displayed effective peroxidase activity and could be used for H2O2 detection. Based on this, a one-step Hx detection method was established using only XOD-ASS as the catalyst. The method displays a good linear relationship in the range from 20 to 100 μM with a detection limit of 6.93 μM. Additionally, we successfully applied this method in testing Hx accumulation in sea bass fish samples of different storage times. The recovery values range from 97.44 to 102.56%. It is exciting to note that, compared with other methods, our proposed method provides a robust advantage on the economic reaction system, ease of preparation, short time consumption, and moderate reaction temperature. We believe that this method shows good application prospects for on-site fish freshness determination.

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 Chlorine-Functional Silsesquioxanes (POSS-Cl) as Effective Flame Retardants and Reinforcing Additives for Rigid Polyurethane Foams

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3979
Author(s):  
Anna Strąkowska ◽  
Sylwia Członka ◽  
Karolina Miedzińska ◽  
Krzysztof Strzelec
Keyword(s):  
Flame Retardants ◽  
Elevated Temperatures ◽  
Bending Strength ◽  
Reaction System ◽  
Fire Retardant ◽  
Polyurethane Foams ◽  
Polymerization Reaction ◽  
Three Point Bending ◽  
One Step

The subject of the research was the production of silsesquioxane modified rigid polyurethane (PUR) foams (POSS-Cl) with chlorine functional groups (chlorobenzyl, chloropropyl, chlorobenzylethyl) characterized by reduced flammability. The foams were prepared in a one-step additive polymerization reaction of isocyanates with polyols, and the POSS modifier was added to the reaction system in an amount of 2 wt.% polyol. The influence of POSS was analyzed by performing a series of tests, such as determination of the kinetics of foam growth, determination of apparent density, and structure analysis. Compressive strength, three-point bending strength, hardness, and shape stability at reduced and elevated temperatures were tested, and the hydrophobicity of the surface was determined. The most important measurement was the determination of the thermal stability (TGA) and the flammability of the modified systems using a cone calorimeter. The obtained results, after comparing with the results for unmodified foam, showed a large influence of POSS modifiers on the functional properties, especially thermal and fire-retardant, of the obtained PUR-POSS-Cl systems.

scholarly journals Administration of a Polyphenol-Enriched Feed to Farmed Sea Bass (Dicentrarchus labraxL.) Modulates Intestinal and Spleen Immune Responses

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Thea Magrone ◽  
Sergio Fontana ◽  
Flavia Laforgia ◽  
Teresa Dragone ◽  
Emilio Jirillo ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
Adaptive Immune Response ◽  
Dicentrarchus Labrax ◽  
Sea Bass ◽  
Distribution Data ◽  
Farmed Fish ◽  
Fish Samples ◽  
Environmental Agents ◽  
Response Increase ◽  
Red Grape

Farmed fish are exposed to a continuous antigenic pressure by microbial and environmental agents, which may lead to a condition of chronic inflammation. In view of the notion that polyphenols, largely contained in fruits and vegetables, are endowed with antioxidant and anti-inflammatory activities, farmed sea bass (Dicentrarchus labraxL.) have been administered with red grape polyphenol-enriched feed. Polyphenols were extracted from the seeds ofCanosinaNero di TroiaVitis viniferaand mixed with conventional feed at two different concentrations (100 and 200 mg/kg, resp.). Fish samples collected at days 223 and 273, respectively, were evaluated for intestinal and spleen cytokine release as well as for spleen macrophage (MØ) and melanomacrophage center (MMC) areas and distribution. Data will show that in treated fish decrease of intestinal interleukin- (IL-) 1βand IL-6 and increase of splenic interferon- (IFN-)γoccur. On the other hand, in the spleen reduction of MØ number seems to parallel increase in MMCs. Collectively, these data suggest that polyphenol-administered sea bass generate lower levels of intestinal proinflammatory cytokines, while producing larger amounts of spleen IFN-γ, as an expression of a robust and protective adaptive immune response. Increase of MMCs corroborates the evidence for a protective spleen response induced by feed enriched with polyphenols.

The Preparation and Sunlight Activity of Nanocomposite Photocatalysts for Degradation of Methyl Orange Solution

2013 ◽  
Vol 750-752 ◽  
pp. 1397-1400 ◽  
Author(s):  
Li Mei Duan ◽  
Jing Hai Liu ◽  
Xiu Ting Xu ◽  
Ling Xu ◽  
Zong Rui Liu
Keyword(s):  
Methyl Orange ◽  
Synthesis Method ◽  
Reaction System ◽  
Methyl Orange Solution ◽  
Degradation Efficiency ◽  
Composite Photocatalyst ◽  
One Step ◽  
Orange Solution ◽  
Xrd And Tem ◽  
Degradation Of Methyl Orange

Applying one-step solvothermal synthesis method, different CdS/TiO2 nanocomposite materials are obtained by changing the ratio of sulfur and titanium sources. The composite structure and morphology are determined by XRD and TEM. Taking the degradation of methyl orange solution as a model reaction, the photocatalytic activity of CdS/TiO2 composite materials is investigated. The results show that the amount of CdS in composite photocatalyst has great effects on the degradation efficiency of methyl orange under the irradiation of sunlight, and the lower pH of reaction system is also needed to sustain the high degradation efficiency for methyl orange.

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)...

Adsorption of anionic azo dyes using lignite coke by one-step short-time pyrolysis

Fuel ◽  
2020 ◽  
Vol 267 ◽  
pp. 117140 ◽  
Author(s):  
Qiongqiong He ◽  
Guoqiang Wang ◽  
Zishan Chen ◽  
Zhenyong Miao ◽  
Keji Wan ◽  
...  
Keyword(s):  
Azo Dyes ◽  
One Step ◽  
Short Time

Kurzzeitpyrolyse, VI Ringverengungen durch CO-Eliminierung aus cyclischen Carbonylverbindungen / Short Time Pyrolysis, VI Ring Contractions by CO-Elimination from Cyclic Carbonyl Compounds

1977 ◽  
Vol 32 (7) ◽  
pp. 805-806 ◽  
Author(s):  
Gerhard Schaden
Keyword(s):  
Gas Phase ◽  
Carbonyl Compounds ◽  
One Step ◽  
Short Time

An one-step synthesis of benzocyclobutene (2) by gas-phase pyrolysis of indane-2-one (1) has been found. By the same method indane-1-one (3) and naphthoquinone(1,4) (5) gave indene-1 -one (4) and fluorene-9-one (7) formed biphenylene (8).

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