scholarly journals Rational Design of an ICT-Based Chemodosimeter with Aggregation-Induced Emission for Colorimetric and Ratiometric Fluorescent Detection of Cyanide in a Wide pH Range

ACS Omega ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 5287-5296
Author(s):  
Sachin D. Padghan ◽  
Li-Ching Wang ◽  
Wei-Chi Lin ◽  
Jiun-Wei Hu ◽  
Wen-Ching Liu ◽  
...  
Keyword(s):  
Rational Design ◽  
Fluorescent Detection ◽  
Aggregation Induced Emission ◽  
Wide Ph Range ◽  
Ph Range

scholarly journals Improvement in Thermostability of an Achaetomium sp. Strain Xz8 Endopolygalacturonase via the Optimization of Charge-Charge Interactions

2015 ◽  
Vol 81 (19) ◽  
pp. 6938-6944 ◽  
Author(s):  
Tao Tu ◽  
Huiying Luo ◽  
Kun Meng ◽  
Yanli Cheng ◽  
Rui Ma ◽  
...  
Keyword(s):  
Rational Design ◽  
Residual Activity ◽  
Maximal Activity ◽  
Wild Type ◽  
Content Type ◽  
Highly Active ◽  
Wide Ph Range ◽  
Enzyme Thermal Stability ◽  
Ph Range ◽  
Charge Interactions

ABSTRACTImproving enzyme thermostability is of importance for widening the spectrum of application of enzymes. In this study, a structure-based rational design approach was used to improve the thermostability of a highly active, wide-pH-range-adaptable, and stable endopolygalacturonase (PG8fn) fromAchaetomiumsp. strain Xz8 via the optimization of charge-charge interactions. By using the enzyme thermal stability system (ETSS), two residues—D244 and D299—were inferred to be crucial contributors to thermostability. Single (D244A and D299R) and double (D244A/D299R) mutants were then generated and compared with the wild type. All mutants showed improved thermal properties, in the order D244A < D299R < D244A/D299R. In comparison with PG8fn, D244A/D299R showed the most pronounced shifts in temperature of maximum enzymatic activity (Tmax), temperature at which 50% of the maximal activity of an enzyme is retained (T50), and melting temperature (Tm), of about 10, 17, and 10.2°C upward, respectively, with the half-life (t1/2) extended by 8.4 h at 50°C and 45 min at 55°C. Another distinguishing characteristic of the D244A/D299R mutant was its catalytic activity, which was comparable to that of the wild type (23,000 ± 130 U/mg versus 28,000 ± 293 U/mg); on the other hand, it showed more residual activity (8,400 ± 83 U/mg versus 1,400 ± 57 U/mg) after the feed pelleting process (80°C and 30 min). Molecular dynamics (MD) simulation studies indicated that mutations at sites D244 and D299 lowered the overall root mean square deviation (RMSD) and consequently increased the protein rigidity. This study reveals the importance of charge-charge interactions in protein conformation and provides a viable strategy for enhancing protein stability.

scholarly journals A multi-functional chemosensor for highly selective ratiometric fluorescent detection of silver(I) ion and dual turn-on fluorescent and colorimetric detection of sulfide

2018 ◽  
Vol 5 (6) ◽  
pp. 180293 ◽  
Author(s):  
Ji Hye Kang ◽  
Ju Byeong Chae ◽  
Cheal Kim
Keyword(s):  
Theoretical Calculations ◽  
Colorimetric Detection ◽  
Fluorescence Emission ◽  
Binding Mode ◽  
Fluorescent Detection ◽  
Mass Spectral ◽  
H Nmr ◽  
Wide Ph Range ◽  
Ph Range ◽  
Nmr Titrations

A multi-functional chemosensor 1 as silver and sulfide detector was synthesized by the combination of octopamine and 4-dimethylaminocinnamaldehyde. Sensor 1 exhibited a ratiometric fluorescence emission for Ag + from blue to sky. The binding mode of 1 and Ag + turned out to be a 1 : 1 ratio as determined using Job plot and electrospray ionization (ESI) mass spectral analyses. The sensing mechanism of 1 with silver ion was unravelled by 1 H NMR titrations and theoretical calculations. Sensor 1 also discerned sulfide by enhancing fluorescence intensity and changing colour from yellow to colourless in aqueous solution. The sensing properties of 1 toward S 2− were investigated by using ESI-mass analysis, Job plot and 1 H NMR titrations. Moreover, 1 could be used as a detector for sulfide in a wide pH range.

Rational design of porous binary Pt-based nanodendrites as efficient catalysts for direct glucose fuel cells over a wide pH range

2017 ◽  
Vol 7 (13) ◽  
pp. 2819-2827 ◽  
Author(s):  
Kamel Eid ◽  
Yahia H. Ahmad ◽  
Siham Y. AlQaradawi ◽  
Nageh K. Allam
Keyword(s):  
Catalytic Activity ◽  
Oxidation Reaction ◽  
Rational Design ◽  
Glucose Oxidation ◽  
Room Temperature ◽  
Ph Values ◽  
Wide Ph Range ◽  
One Step ◽  
Ph Range ◽  
Glucose Oxidation Reaction

Porous binary PtPd, AuPt, PtCu, and PtNi nanodendrites prepared by a facile one-step reduction under ultrasonic irradiation at room temperature, exhibited a substantial catalytic activity towards glucose oxidation reaction at different pH values relative to a commercial Pt/C catalyst.

scholarly journals Rational Design of Atomic Layers of Pt Anchored on Mo 2 C Nanorods for Efficient Hydrogen Evolution over a Wide pH Range

Small ◽  
2019 ◽  
Vol 15 (14) ◽  
pp. 1900014 ◽  
Author(s):  
Yu Qiu ◽  
Zhilin Wen ◽  
Chaoran Jiang ◽  
Xiaojun Wu ◽  
Rui Si ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Rational Design ◽  
Wide Ph Range ◽  
Ph Range

scholarly journals Novel Enzyme-Free Multifunctional Bentonite/Polypyrrole/Silver Nanocomposite Sensor for Hydrogen Peroxide Detection over a Wide pH Range

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4442 ◽  
Author(s):  
Khouloud Jlassi ◽  
Mostafa H. Sliem ◽  
Kamel Eid ◽  
Igor Krupa ◽  
Mohamed M. Chehimi ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Ag Nanoparticles ◽  
Rational Design ◽  
Uv Light ◽  
Low Cost ◽  
Current Response ◽  
Ag Nps ◽  
Hydrogen Peroxide Detection ◽  
Wide Ph Range ◽  
Ph Range

Precise designs of low-cost and efficient catalysts for the detection of hydrogen peroxide (H2O2) over wide ranges of pH are important in various environmental applications. Herein, a versatile and ecofriendly approach is presented for the rational design of ternary bentonite-silylpropyl-polypyrrole/silver nanoarchitectures (denoted as BP-PS-PPy/Ag) via the in-situ photo polymerization of pyrrole with salinized bentonite (BP-PS) in the presence of silver nitrate. The Pyrrolyl-functionalized silane (PS) is used as a coupling agent for tailoring the formation of highly exfoliated BP-PS-PPy sheet-like nanostructures ornamented with monodispersed Ag nanoparticles (NPs). Taking advantage of the combination between the unique physicochemical properties of BP-PS-PPy and the outstanding catalytic merits of Ag nanoparticles (NPs), the as-synthesized BP-PS-PPy/Ag shows a superior electrocatalytic reduction and high-detection activity towards H2O2 under different pH conditions (from 3 to 10). Intriguingly, the UV-light irradiation significantly enhances the electroreduction activity of H2O2 substantially, compared with the dark conditions, due to the high photoelectric response properties of Ag NPs. Moreover, BP-PS-PPy/Ag achived a quick current response with a detection limit at 1 μM within only 1 s. Our present approach is green, facile, scalable and renewable.

Engineering nanoporous Ag/Pd core/shell interfaces with ultrathin Pt doping for efficient hydrogen evolution reaction over a wide pH range

2018 ◽  
Vol 6 (29) ◽  
pp. 14281-14290 ◽  
Author(s):  
C. Yang ◽  
H. Lei ◽  
W. Z. Zhou ◽  
J. R. Zeng ◽  
Q. B. Zhang ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Hydrogen Production ◽  
Hydrogen Evolution Reaction ◽  
Rational Design ◽  
Energy Systems ◽  
Core Shell ◽  
Critical Importance ◽  
Renewable Energy Systems ◽  
Wide Ph Range ◽  
Ph Range

The rational design and fabrication of highly efficient and durable all-pH catalysts for sustainable electrochemical hydrogen production are of critical importance to building renewable energy systems for the future.

Polarographic and spectrophotometric behaviour of some N-p-phenyl substituted benzamidines

1991 ◽  
Vol 56 (12) ◽  
pp. 2791-2799 ◽  
Author(s):  
Juan A. Squella ◽  
Luis J. Nuñez-Vergara ◽  
Hernan Rodríguez ◽  
Amelia Márquez ◽  
Jose M. Rodríguez-Mellado ◽  
...  
Keyword(s):  
Spectrophotometric Study ◽  
Absorption Bands ◽  
Electrochemical Parameters ◽  
Wide Ph Range ◽  
Group A ◽  
Substituent Constants ◽  
Ph Range ◽  
The Waves

Five N-p-phenyl substituted benzamidines were studied by DC and DP polarography in a wide pH range. Coulometric results show that the overall processes are four-electron reductions. Logarithmic analysis of the waves indicate that the process are irreversible. The influence of the pH on the polarographic parameters was also studied. A UV spectrophotometric study was performed in the pH range 2-13. In basic media some variations in the absorption bands were observed due to the dissociation of the amidine group. A determination of the pK values was made by deconvolution of the spectra. Correlations of both the electrochemical parameters and spectrophotometric pK values with the Hammett substituent constants were obtained.

High degradation efficiency of sulfamethazine with the dual-reaction-center Fe-Mn-SiO2 Fenton-like nanocatalyst in a wide pH range

2021 ◽  
Author(s):  
Manoj Kumar Panjwani ◽  
Qing Wang ◽  
Yueming Ma ◽  
Yuxuan Lin ◽  
Feng Xiao ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Reaction Center ◽  
Degradation Efficiency ◽  
Heterogeneous Fenton ◽  
Wide Ph Range ◽  
Ph Range

The development of a heterogeneous Fenton-like catalyst, possessing high degradation efficiency in a wide pH range, is crucial for wastewater treatment. The Fe-Mn-SiO2 catalyst was designed, and prepared by a...

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