The electroactive multilayer films of polyelectrolytes and Prussian blue nanoparticles and their application for H2O2 sensors

Prussian blue (PB) nanoparticles were immobilized in polyelectrolyte (PE) multilayers of various compositions and thickness. Films containing nanoparticles and poly(allylamine hydrochloride) (PAH) were formed using the layer-by-layer adsorption method. A layer of branched poly(ethyleneimine) (PEI) was used to anchor the multilayer structure at the surface of a gold electrode. The films exhibited electroactive properties, increasing with the number of deposited PB layers. The properties of PEI/(PB/PAH) _n multilayers were then compared with the ones containing additionally the conductive polymer poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) (PEDOT:PSS). We found that the addition of the conductive, water-soluble polymer enhances the electroactive properties of the multilayer films. It also increased sensitivity of the multilayer-covered electrodes for electrochemical detection of hydrogen peroxide.     

Synthesis, characterization and immobilization of Prussian blue nanoparticles. A potential tool for biosensing devices

Prussian blue (PB) particles with the size of ca. 5 nm were synthesized and immobilized in a multilayer structure, as a strategy for the potential development of an amperometric transducer for oxidase-enzyme-based biosensors. Multilayer films composed of PB and poly(allylamine hydrochloride) (PAH) were prepared via layer-by-layer (LbL) sequential deposition. The process was carefully monitored by UV-vis spectroscopy and cyclic voltammetry. The increase of the redox current peaks during the layer-by-layer deposition demonstrated that charge propagation within the film occurs. Linear increase of UV-vis absorbance with the number of deposited bilayers indicates that well-organized systems have been elaborated. ITO electrodes coated with PB/PAH films were used successfully for detecting H2O2, sensitivity being dependent on the number of PB/PAH layers.     

A Novel Electrochemical Method for the Analysis of Hydrogen Peroxide with the Use of a Glassy Carbon Electrode Modified by a Prussian Blue/Copper‐Gold Bimetallic Nanoparticles Hybrid Film

A novel Prussian blue/copper‐gold bimetallic nanoparticles hybrid film modified electrode was prepared by electrochemical deposition on a glassy carbon electrode (PB/Cu‐AuNPs/GCE). Morphology and electrochemistry of this electrode were studied by UV‐vis spectroscopy, scanning electron microscopy, X‐ray diffraction, cyclic voltammetry and electrochemical impedance spectroscopy. The sensor showed significantly better electrocatalytic activity for the reduction of hydrogen peroxide in comparison with the single PB/GCE and PB/AuNPs/GCE. This was attributed to the synergistic effect of PB and Cu‐Au bimetallic nanoparticles. Also, the sensor demonstrated an overall high level of performance for the analysis of H₂O₂ in the concentration range from 0.002 to 0.84 mM.     

普鲁士蓝膜电化学行为的EQCM研究

应用循环伏安法于铂电极上电化学沉积PB膜,并由电化学石英晶体微天平技术(EQCM)原位测量了PB膜电沉积过程的频率响应.研究表明,沉积液中添加邻菲咯啉对PB膜结构有影响.有邻菲咯啉参与沉积的PB Pt/QCM电极对H2O2的电催化还原性能优于不含邻菲咯啉沉积液制备的PB Pt/QCM电极.     

一种噻吩基双偶极半菁与普鲁士蓝的静电自组装薄膜

通过交替沉积普鲁士蓝和一种含噻吩的半菁, 制备了一种新的无机-有机杂化静电自组装膜. 用紫外-可见吸收光谱、循环伏安技术和光电化学实验对薄膜进行了表征或光电性质研究. 376和698 nm处薄膜的吸光度随薄膜层数增加线性增加, 表明薄膜的沉积是均匀和可重复的. 薄膜中的普鲁士蓝具有良好的表面控制而非扩散控制的电化学活性, 膜的层数从1增加至5时, 阳极峰电流随膜层数增加而线性增加. 100 mW·cm^-2的白光照射下, 薄膜产生稳定的阴极光电流, 随层数增加线性增长, 层数增加到4层时, 光电流达到最大值. 饱和甘汞电极为参比电极, -0.4 V 偏压下, 4层薄膜产生的光电流密度高达0.28 μA·cm^-2.     

Inkjet printed Prussian blue films for hydrogen peroxide detection

An inkjet printing method is described to fabricate hydrogen peroxide (H(2)O(2)) sensors. Insoluble Prussian blue (PB) nanoparticles were dispersed in aqueous solvent, and were printed on screen printed carbon electrodes with a piezoelectric inkjet printer for H(2)O(2) detection. The electrochemical behavior of the printed sensors was studied by using cyclic voltammetry and chronoamperometry. The printed sensors showed great electrocatalytic activity toward H(2)O(2) and can be used for amperometric detection of H(2)O(2). The calibration curves for H(2)O(2) determination showed a linear range from 0.02 to 0.7 mM with a sensitivity of 164.82 μA M(-1) cm(-2) for the printed PB film. The results showed the feasibility of applying inkjet printing technology on surface modification; the results also provide an alternative way for manufacturing electrochemical sensors.     

Multilayer membranes via layer-by-layer deposition of organic polymer protected Prussian blue nanoparticles and glucose oxidase for glucose biosensing

Polyelectrolyte multilayers (PEMs) are now widely used for bioanalytical applications. In this work, a bilayer of poly(diallydimethylammonium chloride) (PDDA) and poly(sodium 4-styrenesulfonate) (PSS) is consecutively adsorbed on 3-mercapto-1-propanesulfonic acid modified Au electrode surfaces, forming stable, ultrathin multilayer films. Subsequently, Prussian blue nanoparticles protected by PDDA (denoted as P-PB) and negatively charged glucose oxidase (GOx) are consecutively adsorbed onto the PSS-terminated bilayer. The growth of each of the P-PB/GOx bilayers is followed quantitatively using UV-visible absorption spectroscopy and the electrochemical method. The P-PB nanoparticles can catalyze the electroreduction of hydrogen peroxide formed from enzymatic reaction at lower potential and inhibit the responses of interferents, such as ascorbic acid (AA) and uric acid (UA). Performance of the multilayer films can be tailored by controlling the number of bilayers. Under optimal conditions, a linear range of 0.10 to 11.0 mM and a detection limit of 10 microM were achieved. The glucose biosensor has good stability and reproducibility.     

Compact microcubic structures platform based on self-assembly Prussian blue nanoparticles with highly tuneable conductivity

Control of molecular and supramolecular properties is used to obtain a new advanced hybrid material based on Prussian blue nanoparticles (PB NPs). This hybrid material is obtained through a self-assembled Layer-by-Layer (LbL) approach combining the advantageous features of β-cyclodextrin (β-CD) polysaccharides, PB NPs and poly(allylamine hydrochloride) from electrostatic interaction between the deposited layers. Transmission electronic microscopy images suggested that PB NPs were protected by β-CD polysaccharides that prevent the aggregation phenomena. In addition, as confirmed by scanning electronic microscopy images, it was found that PB NPs are organized in microcubic supramolecular like structures via a mesoscale self-assembly process. Interestingly, the 3-bilayer {PAH/PB-CD} film exhibited a higher density of microcubic structures and a high electrochemical response with PB sites available for redox reactions at a supramolecular level. By utilizing fewer bilayers and consequently less material deposition, the formed {PAH/PB-CD} multilayer films of a tuneable conductivity can be expected to have interesting future applications for host-guest like dependent electrochemical biosensing designs.     

Multilayer assembly of Prussian blue nanoclusters and enzyme-immobilized poly(toluidine blue) films and its application in glucose biosensor construction

A multilayered glucose biosensor via sequential deposition of Prussian blue (PB) nanoclusters and enzyme-immobilized poly(toluidine blue) films was constructed on a bare Au electrode using electrochemical methods. The whole configuration of the present biosensor can be considered as an integration of several independent hydrogen peroxide sensing elements. In each sensing element, the poly(toluidine blue) film functioned as both the supporting matrix for the glucose oxidase immobilization and the inhibitor for the diffusion of interferences, such as ascorbic acid and uric acid. Meanwhile, the deposited Prussian blue nanocluster layers acts as a catalyst for the electrochemical reduction of hydrogen peroxide formed from enzymatic reaction. Performance of the whole multilayer configuration can be tailored by artificially arranging the sensing elements assembled on the electrode. Under optimal conditions, the biosensors exhibit a linear relationship in the range of 1 x 10(-4) to 1 x 10(-2) mol/L with the detection limit down to 10(-5) mol/L. A rapid response for glucose could be achieved in less than 3 s. For 1 mM glucose, 0.5 mM acetaminophen, 0.2 mM uric acid, and 0.1 mM ascorbic acid have no obvious interferences (<5%) for glucose detection at an optimized detection potential. The present multilayered glucose biosensor with a high selectivity and sensitivity is promising for practical applications.     

Layer-by-layer self-assembly of Prussian blue colloids

The adsorption of Prussian blue (PB) colloids within layers of polyelectrolytes has been achieved by a reiterative immersion-rinse approach. Multilayer assemblies consisting of alternate layers of these components have been prepared by the layer-by-layer (LbL) self-assembly technique. Both processes have been carefully monitored by cyclic voltammetry and infrared and UV-visible spectroscopy. Linear increase in the IR and UV-visible light absorbance with the number of deposited layers indicates that well-organized lamellar systems have been elaborated. Size and distribution of Prussian blue nanoparticles in these systems have been investigated by AFM. The effect of the molar concentration of the PB dipping solution on the adsorption process and the distribution of the PB colloids has also been described. Finally, magnetic properties of these assemblies have been studied by low-temperature ESR measurements. Indeed, this new approach of hybrid LbL films opens the way to a new class of nanostructured lamellar compounds.     

Enhanced charge transport and incorporation of redox mediators in layer-by-layer films containing PAMAM-encapsulated gold nanoparticles

In this work, we exploit the molecular engineering capability of the layer-by-layer (LbL) method to immobilize layers of gold nanoparticles on indium tin oxide (ITO) substrates, which exhibit enhanced charge transfer and may incorporate mediating redox substances. Polyamidoamine (PAMAM generation 4) dendrimers were used as template/stabilizers for Au nanoparticle growth, with PAMAM-Au nanoparticles serving as cationic polyelectrolytes to produce LbL films with poly(vinylsulfonic acid) (PVS). The cyclic voltammetry (CV) of ITO-PVS/PAMAM-Au electrodes in sulfuric acid presented a redox pair attributed to Au surface oxide formation. The maximum kinetics adsorption is first-order, 95% of the current being achieved after only 5 min of adsorption. Electron hopping can be considered as the charge transport mechanism between the PVS/PAMAM-Au layers within the LbL films. This charge transport was faster than that for nonmodified electrodes, shown by employing hexacyanoferrate(III) as the surface reaction marker. Because the enhanced charge transport may be exploited in biosensors requiring redox mediators, we demonstrate the formation of Prussian blue (PB) around the Au nanoparticles as a proof of principle. PAMAM-Au@PB could be easily prepared by electrodeposition, following the ITO-PVS/ PAMAM-Au LbL film preparation procedure. Furthermore, the coverage of Au nanoparticles by PB may be controlled by monitoring the oxidation current.     

Synthesis and stabilization of Prussian blue nanoparticles and application for sensors

Prussian blue (PB) nanoparticles were synthesized by two methods from FeCl2 and K3Fe(CN)6 and from FeCl3 and K3Fe(CN)6 based on the method published by Fiorito et al., and stabilized by different polymers like polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyallylamine hydrochloride (PAH), polydiallyl-dimethyldiammonium chloride (PDDA) and polystyrene sulfonate (PSS). The effect of the monomer/Fe3+ ratio was studied regarding the average particle size and zeta-potential. The forming PB structure was checked by X-ray diffraction. The stabilization was successful for every applied polymer, but the average particle size significantly differs. Particle size distributions were determined by Malvern type nanosizer equipment and by transmission electron microscope (TEM) and zeta potential values were determined for the obtained stabile samples. The results revealed that by using FeCl2 and K3Fe(CN)6 for PB preparation particles with narrow size distribution and average diameter of 1.7 nm occurred but stabilization was necessary. By the other method the dispersion was stabile with 182 nm particles but the particle size exponentially decreased to 18 nm with increasing PVP concentration. Ultrathin nanofilms were prepared on glass support by the alternating layer-by-layer (LbL) method from PB particles and PAH. The morphology of the prepared films was investigated also by AFM. The films were immobilized on interdigitated microsensor electrodes (IME) and tested in sensing hydrogen peroxide and different acids like acetic acid, hydrochloric acid vapors.     

Prussian blue nanoparticles doped nanocage for controllable immobilization and selective biosensing of enzyme

A conductive nanocage composed of Prussian blue (PB) nanoparticles doped mesocellular silica–carbon foam was prepared. This nanocage possessed ink-bottlelike structure with narrow and controllable pore-size distribution, good biocompatibility and favorable conductivity. The Prussian blue nanoparticles dispersed homogeneously on the mesowalls and provided the nanocage with highly catalytic ability toward the reduction of hydrogen peroxide. The nanocage could be used for volume-selective entrapment of enzyme to prepare a biosensor. The use of the Prussian blue nanoparticles doped nanocage would open new horizons for fabrication of biosensors and biocatalysts.     

Immobilization of Prussian blue nanoparticles onto thiol SAM modified Au electrodes for analysis of DL-homocysteine

Prussian blue (PB) nanoparticles were immobilized onto gold electrodes using L-cysteine, 1,3-propanedithiol, and 1,8-octanedithiol as a bridge between the gold surface and the PB nanoparticles by the self-assembly method. The obtained PB/thiol/Au electrodes exhibit direct and indirect electrocatalytic activity toward DL-homocysteine (HCys) oxidation. It is possible for these PB nanoparticles modified electrodes to be used for the determination of HCys. The text was submitted by the authors in English.     

Electrochemical deposition and mechanism investigation of Prussian blue on graphic carbon paste electrode from an acidic ferricyanide solution

Prussian blue (PB) films were electrochemically deposited on graphite carbon paste electrodes (GCPEs) from an acidic solution of ferricyanide using the potentiodynamic and potentiostatic techniques. Interestingly, we, for the first time, observed that on the surface of GCPE, the electrochemistry of PB films strongly depended on the deposition potential. A maximum formation rate of PB was obtained at a more positive deposition potential (0.4 V vs saturated calomel electrode) on GCPE than that on Au or Pt electrode. The ratio of peak current at ca 0.75 V to the one at 0.19 V varied with the deposition potential. In addition, the electrocatalytic activity of the modified GCPEs towards the reduction of hydrogen peroxide considerably changed with the formation potentials of the PB films. These phenomena can be due to the different formation mechanism of PB at different deposition potentials. Dedicated to Prof. Dr. Teresa Iwasita on the occasion of her 65th birthday in recognition of her numerous contributions to interfacial electrochemistry.     

Spectroelectrochemical identity of Prussian blue films in various electrolytes: comparison of time-derivative voltabsorptometric responses with conventional cyclic voltammetry

Using Prussian blue (PB) electrodeposited on gold-covered foil as a model system, we have demonstrated the usefulness of the time-derivative measurements of absorbance versus potential (linear potential-scan voltabsorptometry) for spectroelectrochemical characterization of thin electrochromic films. The time-derivative signals were monitored for PB at 680 and 420 nm in potassium, sodium and lithium electrolytes. Information obtained from cyclic voltabsorptometry is equivalent or complementary to that from conventional cyclic voltammetry. In the case of PB films investigated in lithium electrolyte, the voltabsorptometric time-derivative peaks are better defined than the respective voltammetric peaks. The combination of voltabsorptometry with voltammetry enables molar absorptivity and/or film loading to be determined. Also, concentration changes of differently colored mixed-valence redox centers can be monitored as a function of applied potential. Received: 16 January 1997 / Accepted: 11 March 1997     

Epitaxial electrodeposition of Prussian blue thin films on single-crystal Au(110)

Epitaxial Prussian blue (PB) films are deposited electrochemically onto a Au(110) substrate. High-resolution X-ray diffraction shows that the PB films have a [111] out-of-plane orientation. The very large lattice mismatch of 148% is reduced to about 1% by the formation of (1 x 2)PB(111)[onemacr;10]//(6 x 5)Au(110)[onemacr;10] and (1 x 2)PB(111)[01onemacr;]//(6 x 5)Au(110)[onemacr;10] epitaxial relationships. Peaks in the cyclic voltammogram of PB on Au(110) are sharper than those on polycrystalline Au, consistent with higher structural order and a single out-of-plane orientation. The development of epitaxial films of PB and PB analogues will allow the measurement of the orientation-dependent properties of these molecular magnets. It will also open the door to the development of novel molecular spintronic devices, such as those which exhibit spin-dependent electron transfer.     

Functionalization of graphene with Prussian blue and its application for amperometric sensing of H2O2

As a two-dimensional carbon material with high surface area and conductivity, graphene shows great promise for designing composite nanomaterials to achieve high-performance electrochemical devices. In this work, we prepared graphene-based nanocomposite material by electrochemically depositing Prussian blue (PB) nanoparticles on the surface of graphene. Fourier transform infrared spectra, SEM, and cyclic voltammetry were used to characterize the successful immobilization of PB. Compared with PB films and graphene sheets, the PB–graphene composite films showed the largest current response to the reduction of H₂O₂, probably due to the synergistic effects between graphene sheets and PB nanoparticles. Therefore, a fast and highly sensitive amperometric sensor for H₂O₂ was obtained with a detection sensitivity of 1.6 μA μM^?1 H₂O₂ per cm² and a linear response range of 50～5,000 μM. The detection limit of H₂O₂ was 20 nM at a signal-to-noise ratio of 3. These obtained results are much better than those reported for carbon nanotubes-based amperometric sensors.     

Effect of electrolyte cations on the charge transfer in films of prussian blue

Charge transfer in films of Prussian blue is studied by cyclic voltammetry and chronoamperometry at potentials of first (PB/PW) and second (PB/PY) redox processes in solutions of potassium, cesium, and ammonium nitrates (pH 4.0). The current relaxation following a film perturbation by a small-amplitude voltage pulse is analyzed with theoretical relationships obtained earlier for the charge transfer in redox polymers. Parameters, characterizing the charge transfer rate (formal diffusion coefficient, instantaneous current), are calculated and analyzed as a function of the film oxidation state and the supporting-electrolyte nature     

In situ synthesis of a Prussian blue nanoparticles/graphdiyne oxide nanocomposite with high stability and electrocatalytic activity

Herein we report an in situ synthesis of Prussian blue nanoparticles (PB) on graphdiyne oxide (GDYO) which acts as an excellent substrate. The hybrid was then used as an electrode with high electrochemical catalytic activity towards hydrogen peroxide. The PB/GDYO hybrid was prepared by simply adding FeCl₃ to GDYO solution, and then mixing with Fe(CN)₆^3 − at room temperature. The GDYO was able to anchor PB in nanoparticle form and stabilize it in neutral and weakly basic solutions. The hybrid was investigated by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and electrochemical measurements. The PB/GDYO hybrid showed high electrochemical catalytic activity and stability for the detection of hydrogen peroxide.