基于聚苯胺-普鲁士蓝/普鲁士蓝复合膜的过氧化氢电化学传感器的制备及表征

利用聚苯胺和普鲁士蓝的协同作用,构建了聚苯胺-普鲁士蓝/普鲁士蓝复合膜的H2O2电化学传感器.聚苯胺的带正电骨架和带负电的普鲁士蓝粒子相互吸引,且聚苯胺提供了很多氧化还原位点,有利于普鲁士蓝粒子的进一步均匀生长,使制备的传感器具备优异的电催化性能.采用扫描电镜和电化学方法对修饰电极进行了表征.在最佳实验条件下,该修饰电...     

Enhanced stability of a Prussian blue/sol-gel composite for electrochemical determination of hydrogen peroxide

We have prepared a sol–gel that incorporates Prussian Blue (PB) as a redox mediator. It is shown that the PB in the pores of the sol–gel retains its electrochemical activity and is protected from degradation at acidic and neutral pH values. TEM and EDX studies revealed the PB nanoparticles to possess a cubic crystal structure and to be well entrapped and uniformly dispersed in the pores of the matrix. The electrocatalytic activity of the materials toward hydrogen peroxide (H₂O₂) was studied by cyclic voltammetry and amperometry. The modified electrode displays good sensitivity for the electrocatalytic reduction of H₂O₂ both in acidic (pH 1.4) and neutral media. The sensor has a dynamic range from 3 to 210 μM of H₂O₂, and the detection limit is 0.6 μM (at an SNR of 3).

Electrocatalytic reduction of hydrogen peroxide at Prussian blue modified electrodes: a RDE study

Electrocatalytic reduction of hydrogen peroxide at Prussian blue modified electrode has been studied with rotating disk electrode in pH 5.5 and 7.3 solutions. It has been shown that the electrocatalytic cathodic reduction obeys Koutecky–Levich relationship at electrode potentials ranging from 0.1 to −0.4 V vs. Ag/AgCl for low concentrations of peroxide not exceeding 0.3 mM. Within this potential window, the calculated kinetic cathodic current ranges within the limits of 2.15–6.09 and 1.00–3.60 mA cm⁻² mM⁻¹ for pH 5.5 and 7.3, respectively. For pH 5.5 and 7.3 solutions, a linear slope of the dependence of kinetic current on electrode potential of −10.8 and −2.89 mA cm⁻² mM⁻¹ V⁻¹, respectively, has been obtained. At a higher concentration of peroxide, exceeding 0.6 mM, deviations from Koutecky–Levich relationship have been observed. These deviations appear more expressed at higher potentials and higher solution pH. The results obtained have been interpreted within the frame of two-step reaction mechanism, including (1) dissociative adsorption of hydrogen peroxide with the formation of OH radicals and (2) one-electron reduction of these radicals to OH⁻ anions. At a higher concentration of peroxide, and especially at a higher pH, the second process becomes rate limiting.     

One-step preparation of a composite consisting of graphene oxide, Prussian blue and chitosan for electrochemical sensing of hydrogen peroxide

We report on the single-step preparation of a composite consisting of graphene oxide (GO), Prussian blue (PB) and chitosan (Chit) that was deposited on a glassy carbon electrode and then used to determine hydrogen peroxide. The composite was obtained by mixing GO, Chit, potassium ferricyanide and ferric chloride and keeping it at 90 °C for 1 h. This method is simple and inexpensive, and does not require purification, centrifugation or sedimentation. Scanning electron microscopy, UV-vis spectroscopy, Fourier transform IR spectroscopy and X-ray diffraction were used to characterize the GO-PB-Chit composites and revealed that PB nanoparticles were formed and uniformly distributed on the surfaces of the GO due to the integrating effects of Chit and GO. The composite displayed electrocatalytic activity in the reduction of hydrogen peroxide to which it responded with good linear relationship in the 1.0 μM to 1.0 mM concentration range, with a detection limit of 0.1 μM (at S/N?=?3).

Visualization of latent fingerprints using Prussian blue thin films

Herein,a facile and effective approach was proposed for visualizing latent fingerprints(LFPs) on two kinds of conductive surfaces by spatially selective electrochemical deposition of Prussian blue(PB) thin films.This strategy exploited the fingerprint residue as an insulating mask and the PB thin films were only generated on the bare surface including the valleys between the papillary ridges,which produced a negative image of LFPs with high resolution up to the third level information.The surface morphology of PB films was characterized by the field emission scanning electron microscopy(FE-SEM).This enhancement technique showed promising performance in selected materials of practical interest.     

Prussian blue solid-state films and membranes as potassium ion-selective electrodes

The use of thin films of Prussian blue and heterogeneous Prussian blue membranes as potassium ion-selective electrodes was investigated. All of the heavier group I cations and NH⁺₄ interfere strongly but there is relatively good selectivity towards Na⁺ with a selectivity coefficient of ca. 5 × 10^?3. The thin-film measurements, based on Prussian blue deposited on platinum, involve conditioning the electrode to a fixed potential according to the method used by Engel and Grabner for copper hexacyanoferrate(III) films. The membrane electrodes were based on mixing Prussian blue with polymeric supporting films such as polystyrene and epoxy. A particularly simple practical configuration involves Prussian blue membranes deposited directly on copper conductors where one membrane serves as a reference electrode. A reversible cell, without liquid junction, is formed with Prussian blue and Ag/AgCl electrodes and this serves as a means for determining an accurate value for the standard reduction potential of Prussian blue, which is found to be 0.238 V vs. Ag/AgCl at 25 °C.     

Sensor for traces of hydrogen peroxide using an electrode modified by multiwalled carbon nanotubes, a gold-chitosan colloid, and Prussian blue

An electrochemical sensor for trace levels of hydrogen peroxide (HP) was fabricated by the self-assembly of multi-walled carbon nanotubes, a gold-chitosan colloid, followed by electrodeposition of Prussian blue. The electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy and other methods. The electrode shows well-defined peaks at 101 mV and 193 mV, the reduction current is linearly related to the concentration of HP in the range from 4.0 to and 19.6 μM. The detection limit of 3.36 μM (at an S/N of 3).     

Efficient nonenzymatic hydrogen peroxide sensor in acidic media based on Prussian blue nanoparticles-modified poly(o-phenylenediamine)/glassy carbon electrode

The Prussian blue nanoparticles(PBNPs) were prepared by a self-assembly process, on a glassy carbon(GC) electrode modified with a poly(o-phenylenediamine)(Po PD) film. The stepwise fabrication process of PBNPs-modified Po PD/GCE was characterized by scanning electron microscopy(SEM) and electrochemical impedance spectroscopy. The prepared PBNPs showed an average size of 70 nm and a homogeneous distribution on the surface of modified electrodes. The PBNPs/Po PD/GCE showed adequate mechanical, electrochemical stability and good sensitivity in comparison with other PB based H_2O_2 sensors. The present modified electrode exhibited a linear response for H_2O_2 reduction over the concentration range of 1–58.22 mmol L ~(-1)with a detection limit of ca. 0.8 mmol L ~(-1)(S/N = 3), and sensitivity of 3187.89 m A(mol L ~(-1)) ~(-1)cm 2using the amperometric method. This sensor was employed for the H_2O_2 determination in real sample and also exhibited good interference resistance and selectivity.     

Self-assembling of Prussian blue nanocubic particles on nanoporous glassy carbon and its use in the electrocatalytic reduction of hydrogen peroxide

In this paper, self-assembled Prussian blue nanocubic particles on nanoporous glassy carbon was developed. The morphology of the PBNP-modified porous glassy carbon was characterized by scanning electron microscopy. The PBNP-GCE-red film-modified electrode was used for the sensitive detection of hydrogen peroxide. The electrochemical behavior of the resulting sensor was investigated using cyclic voltammetry and chronoamperometry. The value of α, k _cat, and D was calculated as 0.35, 1.7 × 10⁵ cm³ mol^?1 s^?1, and 2.6 × 10^?5 cm² s^?1, respectively. The calibration curve for hydrogen peroxide determination was linear over 0–600 μM with a detection limit (S/N = 3) of 0.51 μM.     

Sensitive detection of potassium ion using Prussian blue nanotube sensor

A model K⁺ sensor using Prussian blue nanotubes is fabricated by electrochemical deposition of Prussian blue (PB) within the nanochannels of a porous metal-coated membrane with partially covered pore openings. The PB nanotube sensor exhibits excellent stability giving reproducible peak potentials up to 500 measurement cycles, a very low detection limit of 2.0 × 10⁻⁸ M and extremely wide logarithmic linear ranges between 5.0 × 10⁻⁸–7.0 × 10⁻⁴ M and 7.0 × 10⁻⁴–1.0 M. Negligible interferences by Na⁺, Mg²⁺ and Ca²⁺ are observed and a rapid analysis time of 30 s is readily achieved. The ease of electrodeposition, high stability of PB nanotubes and outstanding analytical performance which surpasses conventional PB voltammetric and potentiometric sensors demonstrates potential sensing applications including ion sensors and biosensors using PB and other metal hexacyanoferrate nanotubes.     

A sensitivity-controlled hydrogen peroxide sensor based on self-assembled Prussian Blue modified electrode

In this communication, a hydrogen peroxide (H₂O₂) sensor based on self-assembled Prussian Blue (PB) modified electrode was reported. Thin film of PB was deposited on the electrode by self-assembly process including multiple sequential adsorption of ferric ions and hexacyanoferrate ions. The as-prepared PB modified electrode displayed sufficient stability for practical sensing application. At an applied potential of ?0.05 V vs. Ag/AgCl (sat. KCl), PB modified electrode with 30 layers exhibited a linear dependence on H₂O₂ concentration in the range of 1 × 10^?6–4 × 10^?4 M (r = 0.9998) with a sensitivity of 625 mA M^?1 cm^?2. It was found that the sensitivity of H₂O₂ sensors could be well controlled by adjusting the number of deposition cycles for PB preparation. This work demonstrates the feasibility of self-assembled PB modified electrode in sensing application, and provides an effective approach to control the sensitivity of PB-based amperometric biosensors.     

Electrochemical and electrocatalytic stability of Prussian blue/Berlin green redox transformation in Prussian blue-polypyrrole composite films

Redox transformation of Prussian blue to Berlin green (PB/BG) in Prussian blue-polypyrrole (PB-PPy) composites synthesized via original one-step method has been studied. It was shown that the nature of anion and composition of background electrolyte play an important role for both the stability and the shape of electrochemical response of composite film during redox transfer of Prussian blue to Berlin green. Nitric acid, phosphoric acid, malic acid and citric acid 0.05 N (eq/L) solutions and the same acids partially neutralized with 0.01 N KOH were used as electrolyte to study the role of potassium ions presence in solution. The most stable electrochemical response of PB/BG redox transfer was obtained for the nitrate anions containing solutions in the presence of potassium ions. Nevertheless, the stability of the electrochemical transformation PB/BG in composite films in other media is enough to detect the sulphite ions content in wine samples via electrocatalytic reaction at the potentials of PB/BG redox transformation.

     

Non-enzymatic electrochemical CuO nanoflowers sensor for hydrogen peroxide detection

The electrocatalytic activity of a CuO flower-like nanostructured electrode was investigated in terms of its application to enzyme-less amperometric H₂O₂ sensors. The CuO nanoflowers film was directly formed by chemical oxidation of copper foil under hydrothermal condition and then used as active electrode material of non-enzymatic electrochemical sensors for H₂O₂ detection under alkaline conditions. The sensitivity of the sensor with CuO nanoflowers electrode was 88.4 μA/mM cm² with a linear response in the range from 4.25 × 10⁻⁵ to 4 × 10⁻² M and a detection limit of 0.167 μM (S/N = 3). Excellent electrocatalytic activity, large surface-to-volume ratio and efficient electron transport property of CuO nanoflowers electrode have enabled stable and highly sensitive performance for the non-enzymatic H₂O₂ sensor.     

Luminescent probes for detection and imaging of hydrogen peroxide

The relevance of hydrogen peroxide (H₂O₂) in biological processes has been underestimated for a long time. In recent years, various reports showed that H₂O₂ not only acts as a cytotoxic compound appearing in the course of oxidative stress, but also functions as an important signaling molecule. Fluorescent probes (or indicators) and nanoparticles that respond selectively to hydrogen peroxide can be applied for intracellular measurements or in vivo imaging, and are superior to electrochemical methods, e.g. in terms of spatial resolution. In contrast to previous reviews that concentrated on the adoption of different probes for certain applications, this survey highlights the basic principles of different probes in terms of their chemical design, structures and functionalities. Thus, the probes are classified according to the underlying reaction mechanism: oxidation, hydrolysis, photoinduced electron transfer, and lanthanide complexation. Other assays are based on fluorescent proteins and nanoparticles, and chemi- or bioluminescent reagents. We confine this review to probes that display a more or less distinct selectivity to hydrogen peroxide. Indicators responding to reactive oxygen species (ROS) in general, or to particular other ROS, are not covered. Finally, we briefly discuss future trends and perspectives of these luminescent reporters in biomedical research and imaging.

A gas sensor based on Prussian blue film for the detection of chlorobenzene vapor

A new resistance-type sensor based on Prussian blue film has been fabricated for the detection of chlorobenzene vapor. The effect of Prussian blue preparation conditions on the response of sensor was studied. The sensor exhibited good response and selectivity to chlorobenzene vapor. The sensor prepared with Fe₂(SO₄)₃ at 298 K has response 8.5 at operating voltage of 10 V. The selectivity of the sensor to chlorobenzene against all other tested gases is exceeding almost by 5.6 times. The sensor showed linear response to chlorobenzene vapor in the concentration range of 24–169 ppm at room temperature and at a 10 V operating voltage. The response and recovery time of the sensor was about 18 and 12 s, respectively. Sensor stability test indicated the sensor had a good stability. Furthermore, seven real samples of chlorobenzene vapor was measured using the sensor. The relative error was in the range of about ±1.3%.     

Electrochemical reduction and kinetics of hydrogen peroxide on the rotating disk palladium-plated aluminum electrode modified by Prussian blue film as an improved electrocatalyst

This paper describes the use of an aluminum electrode plated by metallic palladium and modified by Prussian blue (PB/Pd-Al) in the electrocatalytic reduction of hydrogen peroxide (H₂O₂). The effect of pH on the electroreduction of H₂O₂ on the modified electrode is investigated and a simple irreversible reduction pathway is suggested. The electroreduction kinetics including transfer coefficient α, potential-dependent charge transfer rate constants k _f, and diffusion coefficient D are estimated by means of forced hydrodynamic voltammetry using a rotating disk PB/Pd-Al electrode. The mean values obtained for kinetics are 0.38, 10⁻² cm⁻¹, and 7.6 × 10⁻⁶ cm² s⁻¹, respectively. The long-term stability of the modifying layers on the Al substrate was studied.     

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.     

普鲁士蓝膜的电沉积及其电化学阻抗谱

利用循环伏安法在两种不同组成的电解液中进行铂电极上普鲁士蓝膜的电化学沉积，在氯化钾溶液中测量了修饰膜的循环伏安行为，比较了两种膜的电化学阻抗谱。修饰普鲁士蓝膜铂电极的电化学阻抗谱测量结果表明，沉积条件及其沉积膜厚度均对电子传递过程产生影响。