A Reaction-Diffusion-Reaction System for Forming Periodic Precipitation Bands of Cu-Fe-Based Prussian Blue Analogues: A Recent Study

We propose a simple and novel system to form precipitation patterns of Cu-Fe-based Prussian blue analogues (Cu-Fe PBA) in agarose gel through coupled electrochemical reactions, reactant ion diffusion influenced by electric field, and precipitation reactions. The spatiotemporal evolution, spatial distribution, and crystallite morphologies of the precipitates were investigated by visual inspection, Fe Kα intensity distribution measurements, and optical and scanning electron microscope observations. The observed precipitation patterns and their evolution depended on the applied voltage. Multicolored periodic precipitation bands were stochastically formed under cyclic alternating voltage (4 V for 1 h and then 1 V for 4 h per cycle). The distances between adjacent bands were randomly distributed (0.30 ± 0.25 mm). The sizes and shapes of the crystallites generated in the gel were position-dependent. Cubic but fairly irregular crystallites (0.1–0.8 μm) were formed in the periodic bands, whereas definitely cube-shaped crystallites (1–3 μm) appeared close to the anode. These cube-like reddish–brown crystallites were assigned to Cu-FeII PBA. In some periodic bands, plate-like blue crystallites (assigned to Cu(OH)2) were also present. Future issues for potential applications of the observed periodic banding for selective preparation of Cu-Fe PBA crystallites were discussed.

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X-ray spectroscopic analysis of stochastic, periodic precipitation in Co–Fe-Based Prussian blue analogues

Journal of Analytical Atomic Spectrometry ◽

10.1039/c8ja00068a ◽

2018 ◽

Vol 33 (6) ◽

pp. 957-966 ◽

Cited By ~ 5

Author(s):

Hisashi Hayashi ◽

Yui Sato ◽

Hitoshi Abe

Keyword(s):

Prussian Blue ◽

Water Glass ◽

Spectroscopic Analysis ◽

X Ray ◽

Periodic Precipitation ◽

Prussian Blue Analogues

Stochastic, ripening-induced, periodic precipitation of Co–Fe-based Prussian blue analogues in water-glass gels was analyzed by XRF and XANES spectroscopies.

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RETARDATION EFFECTS IN A FINITE DIFFUSION-REACTION SYSTEM

International Journal of Modern Physics B ◽

10.1142/s0217979208039216 ◽

2008 ◽

Vol 22 (12) ◽

pp. 1947-1959 ◽

Cited By ~ 1

Author(s):

KNUD ZABROCKI ◽

STEFFEN TRIMPER ◽

MICHAEL SCHULZ

Keyword(s):

Reaction System ◽

Reaction Diffusion ◽

Diffusion Reaction ◽

One Dimension ◽

Anisotropic Behavior ◽

Production Term ◽

Spatial Point ◽

Delay Effects ◽

Spatiotemporal Delay ◽

Reaction Processes

The reaction-diffusion process is generalized by including spatiotemporal delay effects. As a first example, we study the influence of a constant production term which is switched off after a finite time. In a second case, all diffusion-reaction processes within a distance R(t) = κtα around a certain spatial point are assumed to contribute to the instantaneous dynamics of the system. There occurs a competition between reaction-diffusion and the accumulation process which leads to a non-trivial stationary state. The evolving concentration profiles are calculated analytically for both a ballistic behavior with α = 1 and a diffusion-like transport with α = 1/2. Because the spatiotemporal delay breaks the reflection symmetry, the profiles reveal an anisotropic behavior. The exact solution in one dimension is supported by numerical simulations.

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An Electrochemical System for Forming Periodic Precipitation Bands of Cu-Fe-Based Prussian Blue Analogues

10.20944/preprints202103.0739.v1 ◽

2021 ◽

Author(s):

Hisashi Hayashi ◽

Tomoko Suzuki

Keyword(s):

Prussian Blue ◽

Applied Voltage ◽

Visual Inspection ◽

Electrochemical System ◽

Spatiotemporal Evolution ◽

Agarose Gels ◽

Periodic Precipitation ◽

Precipitation Patterns ◽

Prussian Blue Analogues ◽

Alternating Voltage

We propose a novel electrochemical system to form precipitation patterns of Cu-Fe-based Prussian blue analogues (Cu-Fe PBA) in agarose gels, using an applied voltage to produce reactant ions. The spatiotemporal evolution, spatial distribution, and crystallite morphologies of the precipitates were investigated by visual inspection, Fe Kα intensity distribution measurements, and optical and scanning electron microscope observations. The precipitation patterns and their evolution depended on the applied voltage. Multicolored periodic precipitation bands were stochastically formed under cyclic alternating voltage (4 V for 1 h and then 1 V for 4 h per cycle). The distances between adjacent bands were randomly distributed (0.30 ± 0.25 mm). The sizes and shapes of the crystallites generated in the gel were position-dependent. Almost cubic but fairly irregular crystallites (0.1–0.8 μm) were formed in the periodic bands, whereas definitely cube-shaped crystallites (1–3 μm) appeared close to the anode. These cube-like reddish-brown crystallites were assigned to Cu-FeII PBA. In some periodic bands, plate-like blue crystallites (assigned to Cu(OH)2) were also present. Future issues for applications of the observed periodic banding were discussed.

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Design and Synthesis of Concentration Gradient Prussian Blue Analogues

Crystal Growth & Design ◽

10.1021/acs.cgd.0c01271 ◽

2021 ◽

Vol 21 (2) ◽

pp. 916-925

Author(s):

SuKyung Jeon ◽

Carissa H. Li ◽

Daniel R. Talham

Keyword(s):

Prussian Blue ◽

Concentration Gradient ◽

Design And Synthesis ◽

Prussian Blue Analogues

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Titelbild: Mesostructured Prussian Blue Analogues (Angew. Chem. 3/2008)

Angewandte Chemie ◽

10.1002/ange.200790263 ◽

2007 ◽

Vol 120 (3) ◽

pp. 427-427

Author(s):

Xavier Roy ◽

Laurence K. Thompson ◽

Neil Coombs ◽

Mark J. MacLachlan

Keyword(s):

Prussian Blue ◽

Prussian Blue Analogues

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“Green” Prussian Blue Analogues as Peroxidase Mimetics for Amperometric Sensing and Biosensing

Biosensors ◽

10.3390/bios11060193 ◽

2021 ◽

Vol 11 (6) ◽

pp. 193

Author(s):

Galina Z. Gayda ◽

Olha M. Demkiv ◽

Yanna Gurianov ◽

Roman Ya. Serkiz ◽

Halyna M. Klepach ◽

...

Keyword(s):

Prussian Blue ◽

Noble Metals ◽

High Sensitivity ◽

Graphite Electrodes ◽

Flavocytochrome B2 ◽

Prussian Blue Analogues ◽

Scientific Investigations ◽

Electrochemically Active ◽

Amperometric Sensing ◽

Prussian Blue Analogs

Prussian blue analogs (PBAs) are well-known artificial enzymes with peroxidase (PO)-like activity. PBAs have a high potential for applications in scientific investigations, industry, ecology and medicine. Being stable and both catalytically and electrochemically active, PBAs are promising in the construction of biosensors and biofuel cells. The “green” synthesis of PO-like PBAs using oxido-reductase flavocytochrome b2 is described in this study. When immobilized on graphite electrodes (GEs), the obtained green-synthesized PBAs or hexacyanoferrates (gHCFs) of transition and noble metals produced amperometric signals in response to H2O2. HCFs of copper, iron, palladium and other metals were synthesized and characterized by structure, size, catalytic properties and electro-mediator activities. The gCuHCF, as the most effective PO mimetic with a flower-like micro/nano superstructure, was used as an H2O2-sensitive platform for the development of a glucose oxidase (GO)-based biosensor. The GO/gCuHCF/GE biosensor exhibited high sensitivity (710 A M−1m−2), a broad linear range and good selectivity when tested on real samples of fruit juices. We propose that the gCuHCF and other gHCFs synthesized via enzymes may be used as artificial POs in amperometric oxidase-based (bio)sensors.

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