scholarly journals Polymer Catalysts Imprinted with Metal Ions as Biomimics of Metalloenzymes

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Joanna Czulak ◽  
Anna Jakubiak-Marcinkowska ◽  
Andrzej Trochimczuk
Keyword(s):  
Metal Ions ◽  
Molecularly Imprinted Polymers ◽  
Active Sites ◽  
Suspension Polymerization ◽  
Transition Metal Ions ◽  
Sorption Process ◽  
Surface Imprinting ◽  
Molecularly Imprinted ◽  
Functional Monomers ◽  
Surface Imprinting Technique

This work presents the preparation and properties of molecularly imprinted polymers (MIPs) with catalytic centers that mimic the active sites of metalloenzymes. The MIP synthesis was based on suspension polymerization of functional monomers (4-vinylpyridine and acrylonitrile) with trimethylolpropane trimethacrylate as a crosslinker in the presence of transition metal ions and 4-methoxybenzyl alcohol as a template. Four metal ions have been chosen for imprinting from among the microelements that are the most essential in the native enzymes: Cu2+, Co2+, Mn2+, and Zn2+. To prepare catalysts, the required loading of metal ions was obtained during sorption process. The catalysts imprinted with Cu2+, Co2+, and Zn2+were successfully used for hydroquinone oxidation in the presence of hydrogen peroxide. The Mn2+-imprinted catalyst showed no activity due to the insufficient metal loading. Cu2+MIP showed the highest efficiency. In case of Cu- and Co-MIP catalysts, their activity was additionally increased by the use of surface imprinting technique.

Template-synthesized ultra-thin molecularly imprinted polymers membrane for the selective preconcentration of dyes

2015 ◽  
Vol 3 (20) ◽  
pp. 10959-10968 ◽  
Author(s):  
Lili Lu ◽  
Xianyang Yue ◽  
Fuquan Lin ◽  
Feng Huang ◽  
Bintian Zhang ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Molecularly Imprinted Polymers ◽  
Surface Imprinting ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Surface Imprinting Technique ◽  
Selective Preconcentration ◽  
Template Substrate ◽  
Double Hydroxides

An ultra-thin molecularly imprinted polymers (MIPs) membrane was synthesizedviaa surface-imprinting technique using layered double hydroxides (LDH) as the template substrate and applied for the selective preconcentration of RhB in wastewater.

Molecularly imprinted polymers by the surface imprinting technique

2020 ◽  
pp. 110231
Author(s):  
Chengya Dong ◽  
Hongxing Shi ◽  
Yuanrui Han ◽  
Yuanyuan Yang ◽  
Ruixin Wang ◽  
...  
Keyword(s):  
Molecularly Imprinted Polymers ◽  
Surface Imprinting ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Surface Imprinting Technique

scholarly journals Rational Design of Molecularly Imprinted Polymers Using Quaternary Ammonium Cations for Glyphosate Detection

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 296
Author(s):  
Mashaalah Zarejousheghani ◽  
Alaa Jaafar ◽  
Hendrik Wollmerstaedt ◽  
Parvaneh Rahimi ◽  
Helko Borsdorf ◽  
...  
Keyword(s):  
Molecularly Imprinted Polymers ◽  
Quaternary Ammonium ◽  
Photoelectron Spectroscopy ◽  
Rational Design ◽  
Water Soluble ◽  
Trimethylammonium Chloride ◽  
Molecularly Imprinted ◽  
Functional Monomers ◽  
Imprinted Polymers ◽  
Quaternary Ammonium Cations

Molecularly imprinted polymers have emerged as cost-effective and rugged artificial selective sorbents for combination with different sensors. In this study, quaternary ammonium cations, as functional monomers, were systematically evaluated to design imprinted polymers for glyphosate as an important model compound for electrically charged and highly water-soluble chemical compounds. To this aim, a small pool of monomers were used including (3-acrylamidopropyl)trimethylammonium chloride, [2-(acryloyloxy)ethyl]trimethylammonium chloride, and diallyldimethylammonium chloride. The simultaneous interactions between three positively charged monomers and glyphosate were preliminary evaluated using statistical design of the experiment method. Afterwards, different polymers were synthesized at the gold surface of the quartz crystal microbalance sensor using optimized and not optimized glyphosate-monomers ratios. All synthesized polymers were characterized using atomic force microscopy, contact angle, Fourier-transform infrared, and X-ray photoelectron spectroscopy. Evaluated functional monomers showed promise as highly efficient functional monomers, when they are used together and at the optimized ratio, as predicted by the statistical method. Obtained results from the modified sensors were used to develop a simple model describing the binding characteristics at the surface of the different synthesized polymers. This model helps to develop new synthesis strategies for rational design of the highly selective imprinted polymers and to use as a sensing platform for water soluble and polar targets.

Promoted photocarriers transfer and increased active sites for optimal CO2–to–CH4 photoconversion via the modification of atomically dispersed transition metal ions in CdZnS nanocrystals

2021 ◽  
Author(s):  
Haibo Huang ◽  
Hui-Ying Zhang ◽  
Feng-Ying Cai ◽  
Y Li ◽  
Jian Lü ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Conversion Rate ◽  
Active Sites ◽  
Transition Metal Ions ◽  
Co2 Photoreduction

Atomically dispersed transition metal ions doped CdZnS nanocrystals were synthesized to delicately tune the selectivity of CO2 photoreduction towards CH4, by which the CZS–Cu2+ achieved an excellent CO2–to–CH4 conversion rate...

Metallo-oxidase Enzymes: Design of their Active Sites

2011 ◽  
Vol 64 (3) ◽  
pp. 231 ◽  
Author(s):  
Zhiguang Xiao ◽  
Anthony G. Wedd
Keyword(s):  
Metal Ions ◽  
Active Sites ◽  
Specific Binding ◽  
Large Family ◽  
Outer Sphere ◽  
Transition Metal Ions ◽  
Substrate Oxidation ◽  
Cellular Functions ◽  
Domains Of Life ◽  
Low Valent

Multi-copper oxidases are a large family of enzymes prevalent in all three domains of life. They couple the one-electron oxidation of substrate to the four-electron reduction of dioxygen to water and feature at least four Cu atoms, traditionally divided into three sites: T1, T2, and (binuclear) T3. The T1 site catalyzes substrate oxidation while a trinuclear cluster (comprising combined T2 and T3 centres) catalyzes the reduction of dioxygen. Substrate oxidation at the T1 Cu site occurs via an outer-sphere mechanism and consequently substrate specificities are determined primarily by the nature of a substrate docking/oxidation (SDO) site associated with the T1 Cu centre. Many of these enzymes ‘moonlight’, i.e. display broad specificities towards many different substrates and may have multiple cellular functions. A sub-set are robust catalysts for the oxidation of low-valent transition metal ions such as FeII, CuI, and MnII and are termed ‘metallo-oxidases’. They play essential roles in nutrient metal uptake and homeostasis, with the ferroxidase ceruloplasmin being a prominent member. Their SDO sites are tailored to facilitate specific binding and facile oxidation of these low-valent metal ions and this is the focus of this review.

scholarly journals Molecularly-Imprinted Calcium Phosphate/Calcium Alginate Composite Microspheres by Surface Imprinting via Silane Crosslinking

2008 ◽  
Vol 26 (8) ◽  
pp. 631-641 ◽  
Author(s):  
Kongyin Zhao ◽  
Ning Gao ◽  
Chao Liu ◽  
Guoxiang Cheng
Keyword(s):  
Calcium Phosphate ◽  
Calcium Alginate ◽  
Gelling Agent ◽  
Surface Imprinting ◽  
Ultraviolet Spectrophotometry ◽  
Molecularly Imprinted ◽  
Functional Monomers ◽  
Composite Microspheres ◽  
New Type ◽  
Crosslinking Agents

This paper describes the development of a new type of molecularly-imprinted composite microspheres. Composite microspheres of calcium phosphate/calcium alginate (CP/CA CMs) were prepared from calcium phosphate and sodium alginate through the use of calcium chloride (CaCl2) as a gelling agent in an inverse suspension. Molecularly-imprinted calcium phosphate/calcium alginate composite microspheres (CP/CA MICMs) were then prepared by surface imprinting using CP/CA CMs as the supporting matrix, ethylene tri(β-methoxy)ethoxysilane (A-172) and γ-amidopropyltriethoxysilane (KH-550) as the functional monomers and crosslinking agents, respectively, and Methyl Orange as the template in aqueous solution. The CP/CA MICMs and non-imprinted composite microspheres (NICMs) were characterized by Fourier-transform infrared spectroscopy and optical microscopy. The adsorption behaviour of the CP/CA MICMs and NICMs were determined by ultraviolet spectrophotometry. The results indicated that molecular imprinting occurs via the crosslinking of silanes on the surface of the CP/CA CMs, and that CP/CA MICMs possess an adsorption capacity which exhibits greater selectivity. A schematic representation of the imprinting and recognition process of CA/CP MICMs by surface imprinting via silane crosslinking was presented.

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