Self‐Assembled Prussian Blue Nanoparticles Based Electrochemical Sensor for High Sensitive Determination of H2O2 in Acidic Media

In this paper, self‐assembled Prussian blue nanoparticles (PBNPs) on carbon ceramic electrode (CCE) were developed as a high sensitive hydrogen peroxide (H₂O₂) electrochemical sensor. The PBNPs film was prepared by a simple dipping method. The morphology of the PBNPs‐modified CCE was characterized by scanning electron microscopy (SEM). The self‐assembled PB film exhibited sufficient mechanical, electrochemical stability and high sensitivity in compare with other PB based H₂O₂ sensors. The sensor showed a good linear response for H₂O₂ over the concentration range 1 μM–0.26 mM with a detection limit of ca. 0.7 μM (S/N=3), and sensitivity of 754.6 mA M^?1 cm^?2. This work demonstrates the feasibility of self‐assembled PBNPs‐modified CCE for practical sensing applications.     

Electrocatalytic Oxidation of Hydrogen Peroxide at a Sol‐gel Derived Carbon Ceramic Electrode Modified with Copper Iodide

A novel modified carbon ceramic electrode using CuI as modifier was fabricated. The copper iodide modified sol‐gel derived carbon ceramic (CIM‐SGD‐CC) electrode has high catalytic ability for electrooxidation of hydrogen peroxide. The charge transfer coefficient (α) and exchange current density (j₀) for the modified electrode were calculated. It has been shown that using the CIM‐SGD‐CC electrode, hydrogen peroxide can be determined by cyclic voltammetry and amperometry with limit of detections 26 and 0.31 μmol L^?1, respectively. The advantages of the modified CCE are its good stability and reproducibility of surface renewal by simple polishing, excellent catalytic activity.     

Reduced Graphene Oxide|Carbon Ceramic Electrode Modified with CdS‐Hemoglobin as a Sensitive Hydrogen Peroxide Biosensor

A sensitive hydrogen peroxide (H₂O₂) biosensor was developed based on a reduced graphene oxide|carbon ceramic electrode (RGO|CCE) modified with cadmium sulfide‐hemoglobin (CdS‐Hb). The electron transfer kinetics of Hb were promoted due to the synergetic function of RGO and CdS nanoparticles. The transfer coefficient (α) and the heterogeneous electron transfer rate constant (k_s) were calculated to be 0.54 and 2.6 s^?1, respectively, indicating a great facilitation achieved in the electron transfer between Hb and the electrode surface. The biosensor showed a good linear response to the reduction of H₂O₂ over the concentration range of 2–240 µM with a detection limit of 0.24 µM (S/N=3) and a sensitivity of 1.056 µA µM^?1 cm^?2. The high surface coverage of the CdS‐Hb modified RGO|CCE (1.04×10^?8 mol cm^?2) and a smaller value of the apparent Michaelis? Menten constant (0.24 mM) confirmed excellent loading of Hb and high affinity of the biosensor for hydrogen peroxide.     

A New Amperometric Biosensor Based on HRP/Nano-Au/L-Cysteine/Poly（o-Aminobenzoic acid）-Membrane-Modified Platinum Electrode for the Determination of Hydrogen Peroxide

The third generation amperometric biosensor for the determination of hydrogen peroxide （H2O2） has been described. For the fabrication of biosensor, o-aminobenzoic acid （oABA） was first electropolymerized on the surface of platinum （Pt） electrode as an electrostatic repulsion layer to reject interferences. Horseradish peroxidase （HRP） absorbed by nano-scaled particulate gold （nano-Au） was immobilized on the electrode modified with polymerized o-aminobenzoic acid （poABA） with L-cysteine as a linker to prepare a biosensor for the detection of H2O2. Amperometric detection of H2O2 was realized at a potential of ＋20 mV versus SCE. The resulting biosensor exhibited fast response, excellent reproducibility and sensibility, expanded linear range and low interferences. Temperature and pH dependence and stability of the sensor were investigated. The optimal sensor gave a linear response in the range of 2.99×10^-6 to 3.55×10^-3 mol·L^-1 to H2O2 with a sensibility of 0.0177 A·L^-1·mol^-1 and a detection limit （S/N = 3） of 4.3×10^-7 mol·L^-1. The biosensor demonstrated a 95% response within less than 10 s.     

Sensitive Nonenzymatic Electrochemiluminescence Determination of Hydrogen Peroxide in Dental Products using a Polypyrrole/Polyluminol/Titanium Dioxide Nanocomposite

A layer-by-layer assembled of a polypyrrole and polyluminol was synthesized through the electrodeposition of pyrrole and luminol in acidic medium on a graphite electrode. The electrode was then modified by casting titanium dioxide (TiO₂) nanoparticles on its surface for enhancing electrochemiluminescence of luminol. The properties of this electrochemiluminescence sensor were studied by cyclic voltammetry, electrochemical impedance spectroscopy, field emission scanning electron microscopy, and energy dispersive X-ray spectroscopy. The results demonstrated that the modification of this electrochemiluminescence sensor shows sensitive response for the determination of hydrogen peroxide. Figures of merit include broad linearity from 1?pmol L^?1 to 4?µmol L^?1 (R²?=?0.996) with a limit of detection as low as 0.40?pmol L^?1 at a signal-to-noise ratio of three and good reproducibility with relative standard deviation of 4% for the determination of a 400?nmol L^?1 hydrogen peroxide solution (n?=?4), along with favorable long-term stability. The presence of glucose, citric acid, uric acid, dopamine, and ascorbic acid at concentrations as high as 100?nmol L^?1 of H₂O₂ did not produce any electrochemiluminescence signals, which demonstrates the selective nature of this modified electrode. The sensor was also used for the determination of H₂O₂ in mouthwash formulations and dental whitelight gels.     

Carbon Electrodes Modified by Nanoscopic Iron(III) Oxides to Assemble Chemical Sensors for the Hydrogen Peroxide Amperometric Detection

In this study we show that nanoparticles of various ferric oxides (hematite, maghemite, amorphous Fe₂O₃, β‐Fe₂O₃ and ferrihydrite) incorporated into carbon paste exhibit electro‐catalytic properties towards hydrogen peroxide reduction. The modified paste electrode performances were evaluated and compared with those obtained with Prussian Blue‐modified carbon paste electrode, which represents an excellent chemical mediator towards the H₂O₂ redox reaction (as widely described in literature). The best catalytic activity was found for carbon paste modified by amorphous ferric oxide with 2–4 nm particle size, which was further tested for possible application as hydrogen peroxide sensor. At pH 7, the limit of detection was 2×10^?5 M H₂O₂ (S/N=3), the calibration curves were linear upto 8.5 mM H₂O₂ (R²=0.998), the measurement reproducibility (RSD=97%, n=4), the interelectrode reproducibility (RSD=16%, n_electrodes=5) and <3 s response time.     

Immobilization of Enzymes on the Nano‐Au Film Modified Glassy Carbon Electrode for the Determination of Hydrogen Peroxide and Glucose

A new enzyme‐based amperometric biosensor for hydrogen peroxide was developed relying on the efficient immobilization of horseradish peroxidase (HRP) to a nano‐scaled particulate gold (nano‐Au) film modified glassy carbon electrode (GC). The nano‐Au film was obtained by a chitosan film which was first formed on the surface of GC. The high affinity of chitosan for nano‐Au associated with its amino groups resulted in the formation of nano‐Au film on the surface of GC. The film formed served as an intermediator to retain high efficient and stable immobilization of the enzyme. H₂O₂ was detected using hydroquinone as an electron mediator to transfer electrons between the electrode and HRP. The HRP immobilized on nano‐Au film maintained excellent electrocatalytical activity to the reduction of H₂O₂. The experimental parameters such as the operating potential of the working electrode, mediator concentration and pH of background electrolyte were optimized for best analytical performance of amperometry. The linear range of detection for H₂O₂ is from 6.1×10^?6 to 1.8×10^?3 mol L^?1 with a detection limit of 6.1 μmol L^?1 based on signal/noise=3. The proposed HRP enzyme sensor has the features of high sensitivity (0.25 Almol^?1cm^?2), fast response time (t_90%≤10 s) and a long‐term stability (>1 month). As an extension, glucose oxidase (GOD) was chemically bound to HRP‐modified electrode. A GOD/HRP bienzyme‐modified electrode formed in this way can be applied to the determination of glucose with satisfactory performance.     

Improvement of Selectivity and Stability of Amperometric Detection of Hydrogen Peroxide Using Prussian Blue‐PAMAM Supramolecular Complex Membrane as a Catalytic Layer

A novel hydrogen peroxide (H₂O₂) sensor was fabricated by using a submonolayer of 3‐mercaptopropionic acid (3‐MPA) adsorbed on a polycrystalline gold electrode further reacted with poly(amidoamine) (PAMAM) dendrimer (generation 4.0) to obtain a film on which Prussian Blue (PB) was later coordinated to afford a mixed and stable electrocatalytic layer for H₂O₂ reduction. On the basis of the electrochemical behaviors, atomic force microscopy (AFM) and X‐ray photoelectron spectra (XPS), it is suggested that the PB molecules are located within the dendritic structure of the surface attached PAMAM dendrimers. It was found that the PB/PAMAM/3‐MPA/Au modified electrode showed an excellent electrocatalytic activity for H₂O₂ reduction. The effects of applied potential and pH of solution upon the response of the modified electrode were investigated for an optimum analytical performance. Even in the presence of dissolved oxygen, the sensor exhibited highly sensitive and rapid response to H₂O₂. The steady‐state cathodic current responses of the modified electrode obtained at ?0.20 V (vs. SCE) in air‐saturated 0.1 mol L^?1 phosphate buffer solution (PBS, pH 6.50) showed a linear relationship to H₂O₂ concentration ranging from 1.2×10^?6 mol L^?1 to 6.5×10^?4 mol L^?1 with a detection limit of 3.1×10^?7 mol L^?1. Performance of the electrode was evaluated with respected to possible interferences such as ascorbic acid and uric acid etc. The selectivity, stability, and reproducibility of the modified electrode were satisfactory.     

A Fe3O4‐Based Chemical Sensor for Cathodic Determination of Hydrogen Peroxide

A new cathodic scheme for hydrogen peroxide (H₂O₂) measurement by Fe₃O₄‐based chemical sensor was described. The unique characteristic of electrocatalytic property was firstly investigated by voltammetry. And then the amperometric response of H₂O₂ was measured at ?0.2 V (vs. Ag/AgCl) by Fe₃O₄ modified glassy carbon rotating disk electrode. The kinetic parameter was also calculated from Koutecky‐Levich plot, and the value was 6.4×10^?4 cm s^?1 in pH 3 citrate buffer. In order to benefit the possible biomedical applications, Fe₃O₄/chitosan modified electrode was also investigated in this experiment. There were several characteristic enhancements by the coated chitosan thin film for H₂O₂ sensor. The calibration curves were found to be linear up to 4.0 and 5.0 mM (r=0.999) in pH 3 and 7 with the detection limits of 7.6 and 7.4 μM L^?1 (S/N=3). The stability was evaluated by the results of half‐life time (t_50%) for 9 months at room temperature and 24 months at 4 °C.     

Flow Injection Determination of Hydrogen Peroxide Using a Carbon Paste Electrode Modified with a Manganese Dioxide Film

Abstract

A manganese dioxide film modified carbon paste electrode was developed for use as an amperometric sensor for the determination of hydrogen peroxide (H₂O₂) in ammoniacal aqueous solutions. The electrode showed a stable response towards H₂O₂ after electrochemical activation. Effects of flow rate, operating potential, concentration, injection volume and interferences were investigated. A linear response towards H₂O₂ from 5 μg.l^?1 to 450 mg.l^?1 and a detection limit (3 signal-to-noise ratio) of 4.7 μg.l^?1 was found. The method was employed for the determination of H₂O₂ in rain water samples.     

Synthesis of Functionalized MWCNTs Decorated with Copper Nanoparticles and Its Application as a Sensitive Sensor for Amperometric Detection of H2O2

Functionalized‐multiwall carbon nanotubes decorated with redox active copper nanoparticles have been fabricated for sensitive enzyme‐less H₂O₂ detection. The new nanocomposite was characterized by Transmission electron microscopy, energy dispersive X‐ray analysis and cyclic voltammetry. The response of the modified electrode to H₂O₂ was examined using amperometry at ?0.45 V vs. Ag/AgCl in a buffer solution at pH 10.0. The developed sensor displayed linear concentration ranges of 0.5–10.0 and 10.0–10000.0 µmol L^?1 with a detection limit of 0.3 µmol L^?1. The proposed sensor displayed good selectivity for H₂O₂ detection in the presence of common interferences such as ascorbic acid.     

Nonenzymatic Hydrogen Peroxide Electrochemical Sensor Based on Au‐HS/SO3H‐PMO (Et) Nanocomposite

A newly nonenzymatic sensor for hydrogen peroxide (H₂O₂) based on the (Au‐HS/SO₃H‐PMO (Et)) nanocomposite is demonstrated. The electrochemical properties of the as‐prepared nanocomposite were studied. It displayed an excellent performance towards H₂O₂ sensing in the linear response range from 0.20 µM to 4.30 mM (R=0.9999) with a sensitivity of 6.35×10² µA µM^?1 cm^?2 and a low detection limit of 0.0499 µM. Furthermore, it was not affected by electroactive interference species. These features proved that the modified electrode was suitable for determination of H₂O₂.     

Synthesis of Ferrocene Based Naphthoquinones and its Application as Novel Non‐enzymatic Hydrogen Peroxide

At present, a highly sensitive hydrogen peroxide (H₂O₂) sensor is fabricated by ferrocene based naphthaquinone derivatives as 2,3‐Diferrocenyl‐1,4‐naphthoquinone and 2‐bromo‐3‐ferrocenyl‐1,4‐naphthoquinone. These ferrocene based naphthaquinone derivatives are characterized by H‐NMR and C‐NMR. The electrochemical properties of these ferrocene based naphthaquinone are investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) on modified glassy carbon electrode (GCE). The modified electrode with ferrocene based naphthaquinone derivatives exhibits an improved voltammetric response to the H₂O₂ redox reaction. 2‐bromo‐3‐ferrocenyl‐1,4‐naphthoquinone show excellent non‐enzymatic sensing ability towards H₂O₂ response with a detection limitation of 2.7 μmol/L a wide detection range from 10 μM to 400 μM in H₂O₂ detection. The sensor also exhibits short response time (1 s) and good sensitivity of 71.4 μA mM^?1 cm^?2 and stability. Furthermore, the DPV method exhibited very high sensitivity (18999 μA mM^?1 cm^?2) and low detection limit (0.66 μM) compared to the CA method. Ferrocene based naphthaquinone derivative based sensors have a lower cost and high stability. Thus, this novel non‐enzyme sensor has potential application in H₂O₂ detection.     

Direct Electrochemistry and Electrocatalysis of Hemoglobin Based on Nafion‐Room Temperature Ionic Liquids‐Multiwalled Carbon Nanotubes Composite Film

A robust and effective composite film combined the benefits of Nafion, room temperature ionic liquid (RTIL) and multi‐wall carbon nanotubes (MWNTs) was prepared. Hemoglobin (Hb) was successfully immobilized on glassy carbon electrode surface by entrapping in the composite film. Direct electrochemistry and electrocatalysis of immobilized Hb were investigated in detail. A pair of well‐defined and quasi‐reversible redox peaks of Hb was obtained in 0.10 mol·L^?1 pH 7.0 phosphate buffer solution (PBS), indicating that the Nafion‐RTIL‐MWNTs film showed an obvious promotion for the direct electron transfer between Hb and the underlying electrode. The immobilized Hb exhibited an excellent electrocatalytic activity towards the reduction of H₂O₂. The catalysis current was linear to H₂O₂ concentration in the range of 2.0×10^?6 to 2.5×10^?4 mol·L^?1, with a detection limit of 8.0×10^?7 mol·L^?1 (S/N=3). The apparent Michaelis‐Menten constant (K_m^app) was calculated to be 0.34 mmol·L^?1. Moreover, the modified electrode displayed a good stability and reproducibility. Based on the composite film, a third‐generation reagentless biosensor could be constructed for the determination of H₂O₂.     

Noncovalent Assembly of Picket‐Fence Porphyrin on Carbon Nanotubes as Effective Peroxidase‐Like Catalysts for Detection of Hydrogen Peroxide in Beverages

A newly developed electrochemical sensor for determination of hydrogen peroxide (H₂O₂) in beverages using a water‐insoluble picket‐fence porphyrin (FeTpivPP) functionalized multiwalled carbon nanotubes (MWNTs) is demonstrated. Introduction of FeTpivPP on MWNTs led to enhanced electron transfer. As a new platform in electrochemical analysis, the resultant sensor showed excellent electrocatalytic activity toward the reduction of H₂O₂ due to the synergic effect between MWNTs and FeTpivPP, thus leading to highly sensitive amperometric sensing of H₂O₂ with a detection limit of 0.05 µmol L^?1. The developed method is successfully used to detect H₂O₂ in beverages and shows great promise for routine sensing applications.     

A Novel Hydrogen Peroxide Biosensor Based on the PDDA‐GNPs/MWNTs Nanocomposite Matrix

A novel nanocomposite designed by the assembly of the positively charged poly(diallyldimethylammonium chloride) protected gold nanoparticles (PDDA‐GNPs), and the negatively charged multi‐walled carbon nanotubes (MWCNTs) on ITO electrode via electrostatic interaction, was used as a supporting matrix for immobilizing hemoglobin (Hb) to develop a high‐performance hydrogen peroxide (H₂O₂) biosensor. The cyclic voltammetrys of immobilized Hb showed a pair of well‐defined and quasi‐reversible redox peaks with the formal potential of ‐0.205V (vs. SCE) and the peak‐to‐peak potential separation of 44 mV at a scan rate of 100 mV×s^?1 in 0.1 mol×L^?1 pH 7.0 PBS. Under the optimized experimental conditions, a linearity range for determination of H₂O₂ was from 2.0 × 10^?6 to 5.2 × 10^?4 mol×L^?1 with a correlation coefficient of 0.9994 (n = 37) and a detection limit of 8.4 × 10^?7 mol×L^?1. The biosensor displayed excellent electrochemical and electrocatalytic response to the reduction of H₂O₂, high sensitivity, long‐term stability, good bioactivity and selectivity.     

A Hydrogen Peroxide Sensor Based on Silver Nanoparticles Biosynthesized by Bacillus subtilis

In this study, silver nanoparticles （AgNPs） were biosynthesized by Bacillus subtilis and used to construct a nonenzymatic hydrogen peroxide （H202） sensor, Scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy confirmed that the AgNPs were prepared successfully with spherical morphol- ogy. The electrochemical properties of the resulted sensor were investigated by cyclic voltammetry, chronoam- perometry and electrochemical impedance spectroscopy. It was found that the sensor exhibited good electrocatalytic activity towards H202 reduction with a wider linear range from 0.05 to 120 mmol.L-1, a detection limit of 8 gmol.L-1 and a fast response time less than 2 s. The sensor exhibited good selectivity for H202 determination in the presence of glucose, acetaminophen, ascorbic acid and uric acid.     

Amperometric Biosensor for Hydrogen Peroxide Based on Electrodeposited Sub-micrometer Gold Modified Glassy Carbon Electrode

IntroductionAmperometricbiosensorofhydrogenperoxideisofpracticalimportancebecauseofitswideapplicationsinchemical,biological,clinical,environmentalandmanyotherfields.Forimprovementofsensor抯quality,vari-ouskindsofchemicalmodificationmethodshavebeendevelopedforreducingredoxoverpotentialsofH2O2atelectrodesurfaces,increasingthedetectionsensitivity,linearrange,stabilityandlivetime.Ithasbeenshownthattheuseofsub-micrometersizedmetalparticlessuchasPt-blackcansignificantlyimprovethequalityofthebiosens…     

Non-enzymatic hydrogen peroxide sensor based on a nanoporous gold electrode modified with platinum nanoparticles

A novel non-enzymatic electrochemical sensor based on a nanoporous gold electrode modified with platinum nanoparticles was constructed for the determination of hydrogen peroxide (H₂O₂). Platinum nanoparticles exhibit good electrocatalytic activity towards hydrogen peroxide. The nanoporous gold (NPG) increases the effective surface area and has the capacity to promote electron-transfer reactions. With electrodeposition of Pt nanoparticles (NPs) on the surface of the nanoporous gold, the modified Au electrode afforded a fast, sensitive and selective electrochemical method for the determination of H₂O₂. The linear range for the detection of H₂O₂ was from 1.0 × 10^?7 M to 2.0 × 10^?5 M while the calculated limit of detection was 7.2 × 10^?8 M on the basis of the 3σ/slope (σ represents the standard deviation of the blank samples). These findings could lead to the widespread use of electrochemical sensors to detect H₂O₂.     

Ruthenium Oxide Hexacyanoferrate Modified Electrode for Hydrogen Peroxide Detection

A sensor for H₂O₂ amperometric detection based on a Prussian blue (PB) analogue was developed. The electrocatalytic process allows the determination of hydrogen peroxide at 0.0 V with a limit of detection of 1.3 μmol L^?1 in a flow injection analysis (FIA) configuration. Studies on the optimization of the FIA parameters were performed and under optimal FIA operational conditions the linear response of the method was extended up to 500 μmol L^?1 hydrogen peroxide with good stability. The possibility of using the developed sensor in medium containing sodium ions and the increased operational stability constitute advantages in comparison with PB‐based amperometric sensors. The usefulness of the methodology was demonstrated by addition‐recovery experiments with rainwater samples and values were in the 98.8 to 103% range.