Ferrocyanide Ions Research Articles

Plasmon-Driven Chemistry in Ferri-/Ferrocyanide Gold Nanoparticle Oligomers: A SERS Study.

The plasmon-driven chemistry of ferri-/ferrocyanide ions inside surface-enhanced Raman spectroscopy (SERS) active hot spots associated with gold nanoparticle oligomers is studied with continuous wave (CW) pump-probe SERS. By comparing with solution-phase normal Raman spectra, the characteristic spectral variations observed upon 532 nm optical pumping can be attributed to an oxidation process that occurs on the surface species followed by desorption of the oxidized surface species from the gold nanoparticles. Interrogating the plasmon-driven processes over a wide range of temperatures reveals that neither process is purely driven by the thermal effects associated with the optical pumping, and the apparent activation energies of both steps are estimated based on semiquantitative SERS analysis. Our observation identifies a more detailed reaction pathway for this classic model system under considerably simplified reaction conditions, adding to the current mechanistic background for future plasmon-driven chemistry studies and applications.

Hot-SWV: Square Wave Voltammetry with Hot Microelectrodes.

A promising strategy to lowering detection limits in electrochemical analysis is the active modulation of the electrode temperature. Specifically, by tuning the electrode's surface temperature one can enhance detection limits due to improved electrode process kinetics and increased mass transfer rates, all without affecting the bulk solution. Motivated by this argument, here we report the development of a new electroanalytical technique based on electrode-temperature modulation, which we call hot square wave voltammetry (Hot-SWV). The technique utilizes the superposition of conventional SWV, already considered as one of the most sensitive voltammetric techniques, and a high frequency alternating current (ac) waveform to electrically polarize microelectrodes. By applying about 100 MHz ac frequencies (with varying Vrms amplitudes), our method generates an electrothermal fluid flow (ETF) in the electrolyte surrounding the electrode, thereby increasing the sensitivity of the SWV-based detection. We demonstrate this by investigating the oxidation of ferrocyanide and iron(II) ions, as well as the reduction of the coordination compound ruthenium(III) hexamine under various experimental conditions. We validate our experimental results against a theoretical model built using finite element analysis and observe agreement within ≤15% error at temperatures ≤39 °C. Using Hot-SWV, we observe at least one-order-of-magnitude improvement in the limit of detection of ferrocyanide ions relative to conventional, mm-size electrodes at 25 °C. In addition, we anticipate that Hot-SWV will be particularly useful for electroanalytical measurements of ultralow (≤pM) concentrations of analytes in environmental and biomedical applications.

Chemically synthesized graphene as a precursor to Prussian blue-based nanocomposite: A multifunctional material for transparent aqueous K-ion battery or electrochromic device

This work describes the preparation of a novel graphene/Prussian blue nanocomposite thin and transparent film and its application as both electrochromic material and cathode for transparent K-ion battery operating in aqueous electrolyte. Large graphene sheets were chemically synthesized from benzene, at a water/benzene liquid/liquid interface, using solid iron chloride as both oxidizing and catalyst, yielding a transparent film stabilized at the liquid/liquid interface that can be easily transferred to desirable substrates. We took advantage of the different iron species remaining as a side-product of the synthesis to promote the Prussian blue growing, through a heterogeneous electrochemical reaction between those iron species in the film and ferrocyanide ions in the electrolyte aqueous solution. Nanocubes of Prussian blue grow over the graphene and cover the entire substrate, yielding a bluish, homogeneous and transparent graphene/Prussian blue multifunctional nanocomposite, which was characterized by different techniques. Finally, we demonstrate two possibilities of a real application of this nanocomposite thin film, as cathodic material for aqueous K+-ion transparent batteries, presenting capacities up to 141 mAh g−1 at 0.093 A g−1, and as electrode in an electrochromic device paired with WO3 and using an aqueous KCl solution as electrolyte, presenting very stable optical variation through 200 electrochromic cycles.

The Development of A Flexible Battery by Using A Stainless Mesh Anode

We have developed a compact and flexible battery, which composes three parts: (1) an anode electrode made for stainless mesh which was heat-treated for 30 min at 500℃ with coated carbon nanotube (CNT), (2) a piece of paper filter-based membrane with the pore size of 0.025 µm and the thickness of 100 µm, and (3) a cathode electrode coated potassium ferricyanide. The battery can generate electricity activated by adding sodium chloride (NaCl) solution to the anode. The battery has a NaCl concentration-dependence characteristic. In this research, we tested 0.5, 1, 3, 5, and 10% NaCl solution, respectively. At 3% NaCl concentration, the maximum power density and current density of 42.3 µW/cm2 and 228 µA/cm2 were obtained, respectively. After the experiments, there was a blue material encountered on the anode surface. By using EDS to analyze the blue material, it could be confirmed that the blue material was ferric ferrocyanide (Prussian blue). The operation principle of this battery was proposed as follows. First, on the anode side, the injected sodium chloride solution oxidizes the stainless mesh surface, then ferric ions and electrons are released. Second, on the cathode side, ferricyanide ions are reduced to ferrocyanide ions by electrons coming from the anode through the external circuit. Simultaneously, ferric ions react with ferrocyanide ions to produce Prussian blue and generate more electrons. This battery can be potentially utilized for applications that require on-demand, disposable, and flexible characteristics. ©2019. CBIORE-IJRED. All rights reserved

A sensitivity enhanced fluorescence method for the detection of ferrocyanide ions in foodstuffs using carbon nanoparticles as sensing agents

A novel fluorescent nanoprobe was for the first time developed for the efficient detection of ferrocyanide ions ([Fe(CN)6]4−) based on nitrogen (N), sulfur (S) and chlorine (Cl) co-doped carbon nanoparticles (N,S,Cl-CNPs). The N,S,Cl-CNPs were fabricated through a simple and ultrafast acid-base neutralization method. The sensing mechanism was based on the quenching effect of [Fe(CN)6]4− on the fluorescence emission of N,S,Cl-CNPs via dynamic interaction. The N,S,Cl-CNPs were found to show high selectivity and sensitivity towards [Fe(CN)6]4− detection with two good linear relationships were achieved in the concentration ranges of 0.01–1.0 μg/mL and 1.0–50.0 μg/mL, respectively, and the detection limits are as low as 3.3 and 21.8 ng/mL, respectively. The proposed fluorescence method was successfully applied for [Fe(CN)6]4− analyses in food samples with high accuracy. The results of this study indicate the great application prospects of N,S,Cl-CNPs for [Fe(CN)6]4− detection in complex food matrix.

Hexacyano Ferrate (III) Reduction by Electron Transfer Induced by Plasmonic Catalysis on Gold Nanoparticles.

Redox reactions are of great importance in environmental catalysis. Gold nanoparticles (Au-NPs) have attracted much attention because of their catalytic activity and their localized surface plasmon resonance (LSPR). In the present study, we investigated, in detail, the reduction of ferricyanide (III) ion into a ferrocyanide (II) ion catalyzed by spherical gold nanoparticles of two different sizes, 15 nm and 30 nm, and excited at their LSPR band. Experiments were conducted in the presence (or absence) of sodium thiosulfate. This catalysis is enhanced in the presence of Au- NPs under visible light excitation. This reduction also takes place even without sodium thiosulfate. Our results demonstrate the implication of hot electrons in this reduction.

Carbon nanomaterial as platform for electrochemical genosensor: A system for the diagnosis of the hepatitis C in real sample

This work describes the development of a genosensor for the detection of the hepatitis C virus (HCV) in real samples. Gold electrodes were modified with graphene oxide functionalized with ethylenediamine (GO-ETD) for the immobilization of a HCV specific probe. HCV infected sera and viral genomic RNA were evaluated using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). EIS measurements showed an increase of about twice in charge transfer resistance values, after addition of HCV genomic RNA. In the DPV analyses, the genosensor was able to discriminate HCV positive serum samples from HCV negative serum, with a difference of 3 times between these samples. It was observed an inverse linear relationship between the values of the peak current of the ferrocyanide ion oxidation and the concentration of the samples. The detection limit was 1:483 (v/v) or 1.36nmol·L−1 of RNA. The developed genosensor enables a selective and specific diagnosis of hepatitis C.

Synthesis and properties of the compositе polyanylin–ferrocianide

Samples of polyaniline and polyaniline-ferricyanide composites were synthesized by the reaction of oxidation polycondensation of aniline. Ammonium peroxide disulfate (NH 4 ) 2 S 2 O 8 was used as an oxidizing agent in this reaction, which was performed in an acid medium (aniline + HCl) or (aniline + H 3 [Fe (CN) 6 ]). Structures of synthesized chemical compounds were studied by IR spectroscopy. Spectral analysis shows the presence of light absorption bands at 1 140 cm-1, which are due to oscillations of the group of atoms –N=Q–N + –B–, which is characteristic of the polaron state of the links of the polyaniline chain. The peak at 1450 cm -1 corresponds to deformation oscillations –N = Q = N groups of polyaniline, and the absorption band with a peak at 1600 cm -1 refers to the deformation oscillations of the N–H groups. An analysis of the results of an IR spectroscopic study suggests that the structure of the composite corresponds to the structure of the emeraldalin salt of polyaniline. The coloring of aqueous solutions of salts containing Cu 2+ ions indicates that they absorb light in the visible range of the spectrum. To determine the wavelength at which the maximum absorption of light is achieved by solution of CuSO 4 , the UV spectrophotometer of theCuSO 4 solutions in the visible region (500–900 nm) was measured with the concentration range 0.00625–0.2 M, from which the maximum was determined. The absorption of light by hydrated Cu 2+ ion accounts for a wavelength of 810 nm. All subsequent measurements of the optical density of the investigated solutions were performed at wavelengths 810 nm. A study was performed on adsorption of CuSO 4 from aqueous solutions on the surface of the polyaniline-ferrocyanide composite at 20 C. To measure adsorption, a method was used to determine the optical density of the solution above the adsorbent. An analysis of experimental data suggests that the polyaniline composite {PAn + H 3 [Fe (CN) 6 ]} is the best adsorbent for heavy metal ion Cu 2+ than the polyaniline itself, the amount of CuSO 4 adsorption on the polyaniline-ferocyanide composite is 0.007 mole/g adsorbent. The presence of a conjugated system in the structure of the polyaniline chain, the component of which are nitrogen atoms with 2 s electron vapor, makes it possible to form complexes of polyyaniline with metal ions, which have vacant electrons for the 3 d energy level. The ferrocyanide ion increases the charge density on polyaniline chains, thereby improving the ability of the composite to adsorb Cu(II) from the aqueous solution. The cyanide complex of the composite can take ions of metals from solutions through the coordination mechanism of the inner sphere, which determines the synergistic effect of the composite components (polyaniline chains and ferrocyanate adsorption centers). Keywords : polyaniline, polyaniline-ferricyanide composites, adsorption Cu 2+ .

Photoreduction of ferricytochrome c in the presence of potassium ferrocyanide.

Ferricytochrome c has been previously shown to photoreduce in the presence of ferrocyanide anions, but the process has been poorly understood. Here, we propose a kinetic model for this phenomenon and support it with resonance Raman measurements that show a clear dependence of photoreduction on the concentration of mixture components and laser power. Our data are consistent with the photoreduction process that is driven by photoexcitation of the heme followed by an electron transfer from the excited state of the heme macrocycle to the heme iron. Concomitantly, the hole in the heme ground state is filled with an electron transferred from a ferrocyanide ion residing in the heme pocket.

Electrochemical Diagnosis of Chemical Switch: Impact of Structural Changes on Charge Transport Mechanism of “Redox Anion Bound Polysilsesquioxane” Film

AbstractHerein, we report the structurally dependent charge transport mechanism of ferrocyanide ions immobilized in a protonated amine functionalized polysilsesquioxane (PSQ) film (Redox polymer film). This redox polymer film shows anion actuated reversible “active to inactive” electrochemical interfaces when the electrolyte anion is changed from chloride to perchlorate as a result of swelling and hydrophobic collapse of the PSQ film, respectively. This concept was successfully applied for switchable electrocatalytic oxidation of ascorbic acid by a [Fe(CN)6]4−‐PSQ film. In addition, it was shown in cyclic voltammetric (CV) studies that the presence of HPO42− and CO32− is leading to strong irreversible structural collapse of the PSQ film, whereas, the presence of SO42− and S2O82− is leading to reversible structural changes of the PSQ film within chloride ion medium. Reversible structural transition between swelling and aggregation (voltammetric response reversibly changing from peak to sigmoidal shape) described in this work is new and provides mechanistic insight into redox polymer electrochemistry and allows differentiating electron hopping from physical motion of redox polymers. Moreover, ion‐exchange between bound redox anions and divalent anions in the electrolyte at fixed positive surface sites of PSQ film was explained in terms of Jones‐Dole B‐coefficient. Electrochemical impedance spectroscopy, Atomic force microscopy, Contact angle measurement and UV‐visible spectroscopy analysis of above phenomenon were consistent with CV results.

Re-evaluation of sodium ferrocyanide (E535), potassium ferrocyanide (E536) and calcium ferrocyanide (E538) as food additives.

The Panel on Food Additives and Nutrient Sources added to Food (ANS) provided a scientific opinion re‐evaluating the safety of sodium ferrocyanide (E 535), potassium ferrocyanide (E 536), and evaluating the safety of calcium ferrocyanide (E 538) as food additives. The Panel considered that adequate exposure and toxicity data were available. Ferrocyanides (E 535–538) are solely authorised in two food categories as salt substitutes. To assess the dietary exposure to ferrocyanides (E 535–538) from their use as food additives, the exposure was calculated based on regulatory maximum level exposure assessment scenario (maximum permitted level (MPL)) and the refined exposure assessment scenario. Dietary exposure to ferrocyanides was calculated based on mean and high levels consumption of salts in both the regulatory maximum level and the refined scenario. In the MPL scenario, the exposure to ferrocyanides (E 535–538) from their use as a food additive was up to 0.009 mg/kg body weight (bw) per day in children and adolescents. In the refined estimated exposure scenario, the exposure was up to 0.003 mg/kg bw per day in children and adolescents. Absorption of ferrocyanides is low and there is no accumulation in human. There is no concern with respect to genotoxicity and carcinogenicity. Reproductive studies were not available, but a no observed adverse effect level (NOAEL) of 1,000 mg sodium ferrocyanide/kg bw per day (highest dose tested) was identified from a prenatal developmental toxicity study. The kidney appeared to be the target organ for ferrocyanides toxicity and 4.4 mg sodium ferrocyanide/kg bw per day was identified as the NOAEL for the renal effects in a chronic (2‐year) study in rats. Assuming that the toxicity of this compound is due to the ferrocyanide ion only, the Panel established a group acceptable daily intake (ADI) for sodium, potassium and calcium ferrocyanide of 0.03 mg/kg bw per day expressed as ferrocyanide ion. The Panel concluded that ferrocyanides (E 535–538) are of no safety concern at the current authorised use and use levels.

Assessment of ferrocyanide intake from food-grade salt in the Korean population

A simple high-performance liquid chromatography-ultraviolet (HPLC-UV) method for estimating the daily intake of ferrocyanide (FeCN) ion from food-grade salts was developed and validated. The levels of FeCN ion in food-grade salts available in Korean markets were analysed. FeCN ion was detected in 8.9% of 801 samples, with concentrations ranging from ND (not detected) to 9.6 mg/kg. The FeCN-ion levels were below the legal limit (10 mg/kg) specified by the Korean Food Code. The FeCN-ion intake of the Korean population was evaluated by combining food-intake data from the 2012–2014 Korea National Health and Nutrition Examination Survey (KNHANES), and the concentration data. The mean estimated daily intakes (EDIs) of the general population and consumers were 0.010 and 0.012 μg/kg bodyweight (bw)/day, respectively, when the mean values from the tested samples were used. The 95th percentile intake levels of both groups were 0.036 and 0.039 μg/kg bw/day, respectively. The EDIs of FeCN ion for all groups were much lower than the acceptable daily intake (ADI) of 0.025 mg/kg bw/day. These results provide useful information about the use of FeCNs as anticaking agents for consumers and manufacturers.

Experimental study of electrochemical mass transfer in an annular duct with the electrolyte nanofluid

The paper shows experimental studies on mass transfer phenomena in the nanofluid flowing through an annular channel. The effect of aluminium oxide nanoparticles on mass transfer was investigated in the channel with hydraulic diameter 10.5 mm.The experiment was performed using the electrochemical limiting current technique.A classical system for mass transfer measurements, based on ferricyanide ion reduction at the cathode and ferrocyanide ion oxidation at the anode has been applied. The base fluid (base-electrolyte) was composed of equimolar potassium ferri-ferrocyanide solution and sodium hydroxide solution. The nanofluid tested (nano-electrolyte) was composed of the base-electrolyte and spherical, 99.9% pure aluminium oxide nanoparticles, of about 40 nm in diameter. The nano-electrolyte used was characterized by volume particle fractions: 0.005%, 0.01%, 0.015%, 0.02%, 0.025%, 0.04%, 0.05% and 0.06%.Mass transfer processes during the forced transitional and turbulent flow of the nano-electrolyte through the horizontal annular channel were investigated. The fully developed hydrodynamic profile was considered. Mass transfer coefficients at the cathode attached to the inner surface of the channel were measured. The experiment was performed with the Reynolds numbers ranging from 2080 to 10430. Bulk ion concentrations in the electrolyte were measured experimentally during each test which minimized errors resulting from ion concentration decomposition. There occurred changes in the mass transfer coefficients depending both on nanoparticle concentration and the Reynolds number. With an increase in nanoparticle fraction, mass transfer was reduced. Measurements for the transitional and turbulent regime indicated that the mass transfer coefficients achieved their lowest values at the largest value of nanoparticle fraction. However, the reduction in mass transfer was not proportional to an increase in particle fraction. The maximum reduction of about 12% was observed for the largest Re numbers and the maximum particle fraction.

Exploring Ferrocyanide-Mediated Photoreduction Mechanics of Cytochrome C in the Presence and Absence of Cardiolipin

Upon interacting with cardiolipin (CL), ferricytochrome c has been shown to lose its native M80 ligation and gain peroxidase activity in what is known as a pivotal step in the protein's role in initiating apoptosis. The system can be difficult to study spectroscopically due to the co-existence of multiple conformational states, and yet this co-existence of native and partially-unfolded conformations is an important factor to quantify due to its clear biological significance. We have previously shown that ferrocyanide-mediated photoreduction as probed by Soret band resonance Raman (RR) spectroscopy can be used to quantify the amount of non-native conformers of cytochrome c during binding to CL-containing membranes when analyzed using the model of Pandiscia and Schweitzer-Stenner. However, the question of whether the photoreduction itself perturbs the system by pumping the protein into the reduced state - or whether the oxygen-mediated oxidation of ferricytochrome c as shown by Serpas et al. restores the equilibrium - has still remained unanswered. RR spectra measured under anaerobic conditions show that the equilibrium is indeed shifted towards the ferro- state even in the presence of CL after extended periods of time. Furthermore, we explored the mechanics of photoreduction itself by measuring RR spectra at different 442 nm laser wattages and ferrocyanide ion / cytochrome c concentrations. This method was extended to different laser lines in order to determine whether the mechanism of photoreduction is excitation wavelength dependent. This idea was further explored using different redox couples.

Nail polish and carbon powder: An attractive mixture to prepare paper-based electrodes

A simple and inexpensive procedure of paper-based electrode (PE) fabrication using A4 size conventional paper, nail polish and carbon powder is reported. The device was prepared by spreading the carbon conductive ink directly onto the paper substrate using a paint-brush. The best composition of the conductive ink was 80:20% (m:m) carbon powder: nail polish and the best device was obtained with 100 mg (2.5 mg cm−2) of carbon conductive ink spread on the paper piece. The proposed device showed satisfactory stability in acidic, neutral and alkaline medium in presence of ferrocyanide ion used as electrochemical probe. Dopamine was selected as a target compound to evaluate the possibility of using the proposed device for electroanalytical purposes. Differential pulse voltammetry was used in these studies and dopamine detection was achieved at +0.13 V vs. Ag/AgClsat in phosphate buffer solution pH = 7 with a detection limit of 5.2 μmol L−1. The proposed device represents an interesting advance in the field of PE construction since it combines satisfactory electrochemical stability and electroanalytical performance with simplicity and widely available low-cost materials. Moreover, chemical modifiers can be easily added to the conductive ink. Therefore, this versatile device brings exciting possibilities for future electroanalytical applications mainly for those that require small and/or flexible devices, such as the amperometric detection in microfluidic systems.

Determination of Cd and Zn with “green” screen-printed electrodes modified with instantly prepared sparked tin nanoparticles

Graphite screen-printed electrodes (GSPEs) modified with tin nanoparticles (SnNPs) through a “green”, fast and extremely facile sparking process were used for the anodic stripping voltammetric determination of trace Cd and Zn. The effect of the magnitude of the energy dissipated during sparking events as well as other sparking parameters on the amount of the deposited tin, the morphology of the sparked surfaces and the electroanalytical properties of SnNP/GSPEs were investigated. Experiments were performed in the presence of bromide ions, which were used to enable well-resolved stripping peaks for cadmium. Other experimental variables, such as the pH of the supporting electrolyte, the square wave voltammetry parameters, the concentration of bromide ions, the deposition potential and the deposition time were also examined. Copper interference on Cd and Zn detection was effectively alleviated by the addition of ferrocyanide and gallium ions, respectively. Under selected conditions, the limits of detection, for a 2 min preconcentration time, were 0.5 μg L−1 Cd and 0.3 μg L−1 Zn. SnNP/GSPEs were successfully applied to the determination of Cd and Zn in tap and bottled water samples. Results suggest that sparked SnNP/GSPEs represent a new promising type of environmentally friendly sensors for the determination of Cd and Zn in the sub-microgram-per-liter level that surpass those previously given in the literature in terms of simplicity, cost, time, labor effort, waste loadings of the modification procedure, and low cost of the final sensor.

Development and validation of HPLC method for the determination of ferrocyanide ion in food grade salts

A rapid, simple, and reliable HPLC method was developed and validated to determine the presence of ferrocyanide ions (FeCNs) in food grade salts. An analytical column coupled with a guard column and mobile phase comprised of sodium perchlorate and sodium hydroxide (NaOH) were employed at a detection wavelength of 221nm. Samples were dissolved in 0.02M NaOH solution and filtered. For processed salts including herbs and spices, a C18 cartridge was applied to minimize interference from salt matrices. The method validation was based on linearity, accuracy (recovery), precision, LOD, LOQ, and measurement uncertainty. This method exhibits good linearity from 0.1−10mg/L (r2=0.9999). The LOD and LOQ values were determined to be 0.02 and 0.07mg/kg, respectively. The FeCN recoveries in six salt matrices ranged from 80.3−102.2% (RSD=0.3–4.4%). These results indicate that the proposed method is suitable for FeCN ion determination in various food grade salts.

Development of an electrochemical differential pH sensing system based on mebendazole and potassium ferrocyanide

This work describes the development of a novel differential voltammetric pH sensing system based on carbon nanoparticles (CNPs) thin film modified glassy carbon electrode (GCE). The pH measurement was performed based on the redox response of mebendazole (Meb) against redox response of ferrocyanide ion. Voltammograms recorded in various buffer solutions (pH 2.0–10.5) containing Meb and ferrocyanide ion yielded two distinct redox processes through which to ascribe the peak potential of Meb with Nernstian (−55 mV/pH at T at 25 °C) manner versus peak potential of ferrocyanide ion. This method involves very sensitive and convenient differential measurements in peak potential. It is based on a pH-dependent redox process of Meb versus pH independent redox process of ferrocyanide ion over the aqueous pH range 2.0–10.5. The developed system displays acceptable performances in buffered and unbuffered solutions, obeying a reproducible Nernstian response versus pH changes. The high stability, reproducibility, and accuracy exhibited by the proposed procedure are good enough to consider it as a suitable system for pH measurement in various aqueous media.

Prussian Blue nanoparticles as optical probes for visual and spectrophotometric determination of silver ions

The authors report on a method for visual and spectrophotometric determination of silver (I) by using Prussian Blue nanoparticles (PB NPs) as a colorimetric probe. It is based on the finding that the blue PB NPs are converted into colorless silver ferrocyanide ions in the presence of Ag(I) due to the establishment of a dissolution-precipitation equilibrium. The change in absorbance at 700 nm is related to the concentration of Ag(I) in the range from 0.01 to 3 μM. The visual detection limit is 3 μM. The assay has a good selectivity for Ag(I) over other common ions. It was successfully applied to the determination of Ag(I) in spiked samples of river and lake waters.

Development of zinc ferrocyanide ion exchange compounds for corrosion-inhibiting and sensing pigments

The fabrication and application of zinc ferrocyanide ion exchange compounds for use as inhibiting and sensing pigments in protective paints and primers for metals and alloys are described in this paper. A distinctive property of these ferrocyanide pigments is an ability to store corrosion inhibitors and then release them when needed by an ion exchange process. The exchange process is triggered when moisture containing Na+ and K+ ions contacts inhibitor particles embedded in an organic coating. The exchange kinetics were studied by measuring the concentration of released zinc ions in the solution with inductively coupled plasma. The inhibitor storage capacity can be as high as 200 meq/100 g, and it is much higher than that found in other reported ion exchange compounds. Furthermore, structure changes from non-crystalline to crystalline, upon exchange with alkaline ions, can be detected by x-ray diffraction, providing an important indication of activation of the corrosion protection. This is a form of corrosion sensing. The inhibition performance of zinc ferrocyanide in the coating was examined by salt spray tests and electrochemical impedance spectroscopy, and both tests showed that zinc ferrocyanide could provide good protection on aluminum alloy 2024.