Peroxide Electrochemical Sensor Research Articles

Fabrication of Cu2O/rGO Hydrogel Film and its Application as Electrochemical Hydrogen Peroxide Sensor

Fabrication of Cu2O/rGO Hydrogel Film and its Application as Electrochemical Hydrogen Peroxide Sensor

Electrochemical Reversible Copper Oxide (CuO) System on Multiwalled Carbon Nanotube Paste Electrode (CPE) as Sensor for Hydrogen Peroxide in Wound Cleaning Solution

An electrochemical sensor for hydrogen peroxide (H2O2) was prepared and optimized in this study. The sensor recognition element consisted of mainly copper oxide (CuO) particles electrodeposited on an anodized multiwalled carbon nanotube paste electrode (MWCPE), which is composed of multiwalled carbon nanotubes (MWCNT) and polydimethylsiloxane (PDMS). Chronoamperometry (CA) was used as the electrodeposition technique both for Cu deposition and oxidation to CuO. The layer of CuO was shown to react with H2O2, which lead to measurable voltammetric current at varying concentrations of H2O2. Different parameters were optimized as follows: Cu deposition time, Cu oxidation time, and equilibration time. Differential pulse voltammetry (DPV) was used as the main sensing technique for CuO-CPE. DPV measurements showed that the average peak current (ave. Ip) was found to be increasing linearly with increasing H2O2 concentration. Two H2O2 concentration ranges, low concentration (20 μM – 100 μM) and high concentration (400 μM – 1200 μM), were observed to have a linear correlation with ave. Ip. The limits of detection (LODs) were calculated to be equal to 11.40 µM using the low concentration range, while 13.04 μM using the high concentration range. The H2O2 measurements using CuO-CPE were found to be reproducible and repeatable. Real sample analysis was also performed on a wound cleaning solution (aqua oxigenada, 6% H2O2 w/w) as a sample. From the measurements, the H2O2 concentration of the analyte was found to be 6.16% w/w; the calculated % error was equal to 2.67%. Overall, CuO-CPE composite was shown to be an effective electrochemical sensor for H2O2 analysis.

An electrochemical hydrogen peroxide sensor for applications in nuclear industry

Hydrogen peroxide is a radiolysis product of water formed under gamma-irradiation; therefore, its reliable detection is crucial in the nuclear industry for spent fuel management and coolant chemistry. This study proposes an electrochemical sensor for hydrogen peroxide detection. Cysteamine (CYST), gold nanoparticles (GNPs), and horseradish peroxidase (HRP) were used in the modification of a gold electrode for fabricating Au/CYST/GNP/HRP sensor. Each modification step of the electrode was investigated through electrochemical and physical methods. The sensor exhibited strong sensitivity and stability for the detection and measurement of hydrogen peroxide with a linear range of 1–9 mM. In addition, the Michaelis–Menten kinetic equation was applied to predict the reaction curve, and a quantitative method to define the dynamic range is suggested. The sensor is highly sensitive to H2O2 and can be applied as an electrochemical H2O2-sensor in the nuclear industry.

Amplified Electrochemical Hydrogen Peroxide Sensing Based on Cu-Porphyrin Metal-Organic Framework Nanofilm and G-Quadruplex-Hemin DNAzyme.

A novel electrochemical hydrogen peroxide (H2O2) sensor based on Cu-porphyrin(Cu-TCPP)/G-quadruplex-hemin nanocomposite was constructed by assembling two-dimensional Cu-TCPP metal-organic framework (MOF) nanofilm and G-quadruplex-hemin DNAzyme. The Cu-TCPP synthesized by the surfactant-assisted method has a wrinkled two-dimensional nanofilm morphology, which gives it a large surface area and accessible active sites. Cu-TCPP exhibits peroxidase activity and good stability and can catalyze the reduction of H2O2. In addition, Cu-TCPP can be used as a nanocarrier for G-quadruplex-hemin DNAzyme with strong peroxidase activity to achieve "biological barcode" amplification and improve stability. The cooperative interaction of Cu-TCPP and G-quadruplex-hemin DNAzyme effectively amplifies the electrochemical response signal. Electrochemical studies have shown that the constructed sensor exhibits good electrochemical sensing performance with three linear ranges: 0.08 μM to 0.11 mM, 0.11-0.91 mM, and 0.91-8.1 mM, with sensitivities of 2315.86, 301.00, and 65.71 μA/(mM cm2), respectively, and the detection limit was 0.03 μM. In addition, the sensor shows good selectivity. In summary, this study provides a simple and effective new strategy for electrochemical sensing based on two-dimensional MOFs and artificial enzymes.

Electrochemical Sensor Based on Prussian Blue Electrochemically Deposited at ZrO2 Doped Carbon Nanotubes Glassy Carbon Modified Electrode.

In this work, a new hydrogen peroxide (H2O2) electrochemical sensor was fabricated. Prussian blue (PB) was electrodeposited on a glassy carbon (GC) electrode modified with zirconia doped functionalized carbon nanotubes (ZrO2-fCNTs), (PB/ZrO2-fCNTs/GC). The morphology and structure of the nanostructured system were characterized by scanning and transmission electron microscopy (TEM), atomic force microscopy (AFM), specific surface area, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman and Fourier transform infrared (FTIR) spectroscopy. The electrochemical properties were studied by cyclic voltammetry (CV) and chronoamperometry (CA). Zirconia nanocrystallites (6.6 ± 1.8 nm) with cubic crystal structure were directly synthesized on the fCNTs walls, obtaining a well dispersed distribution with a high surface area. The experimental results indicate that the ZrO2-fCNTs nanostructured system exhibits good electrochemical properties and could be tunable by enhancing the modification conditions and method of synthesis. The fabricated sensor could be used to efficiently detect H2O2, presenting a good linear relationship between the H2O2 concentration and the peak current, with quantification limit (LQ) of the 10.91 μmol·L−1 and detection limit (LD) of 3.5913 μmol·L−1.

Synthesis and characterization of Fe3O4-supported metal–organic framework MIL-101(Fe) for a highly selective and sensitive hydrogen peroxide electrochemical sensor

In this study, an electrochemical sensor for the quantification of hydrogen peroxide (H2O2) based on nafion glassy carbon electrode (NGCE) modified with MIL-101(Fe)@Fe3O4 metal–organic frameworks (MOFs) was developed. Its electrochemical performance and surface analyses were examined with various techniques. The MIL-101(Fe)@Fe3O4/NGCE sensor exhibited a well-defined redox peak towards H2O2 since the frameworks provide high electronic conductivity and easy mass transfer for target molecules. The parameters that affected the performance of the developed sensor were optimized. The proposed sensor showed a low detection limit (0.15 μM) and relatively good sensitivity (68.8312 μAmM−1 cm−2) according to the differential pulse voltammetry (DPV) method. Furthermore, the chronoamperometry (CA) method exhibited high sensitivity (556.5037 μAmM−1 cm−2) but a relatively low detection limit (1.76 μM), and the proposed sensor demonstrated excellent repeatability. Furthermore, the sensor was applied for the detection of H2O2 in industrial samples.

Copper oxide immobilized clay nano architectures as an efficient electrochemical sensing platform for hydrogen peroxide

An electrochemical sensor for hydrogen peroxide (H2O2) present in face bleach cream is fabricated using a composite based on bentonite (Bt) clay and copper oxide (CuO) nanoparticles (CuO-Bt). The CuO nanoparticles’ immobilization into Bt was carried out by a two-step process in which Cu2+ is ion-exchanged into Bt layers (Cu2+-Bt) in the first step followed by the chemical reaction of NaOH with Cu2+-Bt in the second step to get the target material, CuO nanoparticles immobilized Bt (CuO-Bt). The successful immobilization of CuO nanoparticles into Bt is investigated by a variety of techniques like scanning electron microscopy, transmission electron microscopy, FT-IR spectroscopy, UV-Vis spectroscopy, and electrochemical methods. The CuO-Bt composite is coated on a glassy carbon electrode and used as a selective electrochemical sensing platform for the determination of H2O2 based on the significant electrocatalytic property of CuO-Bt towards the H2O2 oxidation. This amperometric electrochemical sensor shows two linear detection ranges (5–50 μM and 50–10000 μM) with a limit of detection of 4.9 μM. The sensitivity is calculated to be 0.06 µA µM−1 cm−2. This electrochemical sensor exhibits high selectivity, stability, and practical applicability for the H2O2 determination in real samples.

Nonenzymatic Hydrogen Peroxide Electrochemical Sensor Based on Inkjet-Printed Reduced Graphene Oxide

The vital role of hydrogen peroxide (H2O2) in many enzyme-catalyzed reactions, has attracted much interest to develop novel approaches for accurate and fast detection of this simple compound [2]. Also, the determination of the hydrogen peroxide level is essential in food processing, environmental analysis, and clinical diagnosis [2]. Reduced graphene oxide (rGO) has shown to be a superior electrode material for electrochemical analysis due to its high electron transfer rate and active surface area [3]. However, the fabrication of such rGO-based electrodes involves complicated and expensive fabrication processes. Herein, we present a disposable, simple, and low-cost H2O2 electrochemical sensor based on rGO for amperometric detection of hydrogen peroxide concentration.First, the rGO ink material was prepared by mixing 10 ml of graphene oxide (GO) solution with 10 ml of DI water, and sodium dodecyl sulfate (2 mg/ml). The SDS works as a surfactant and reduces the possibility of printer nozzle clogging. The solution was sonicated for 30 minutes and was loaded to a cartridge of an office inkjet printer. To achieve a thicker layer of GO, the printing process was repeated 25 times on a PET film. Next, the electrodes were placed inside hydroiodic (HI) acid for 24 hours at 100 oC to remove oxygenated groups from GO molecular structure. The color of the electrodes became darker after the GO was reduced to rGO (Figure 1.A). Then, the printed pattern was sliced into 20 by 2.5 mm electrodes, and the resistance of the electrode was measured to validate the reduction process.The step voltammetry method was adopted to measure the H2O2 inside 0.1 M PBS buffer. The solution was stirred at 200 rpm, and -800 mV vs. Ag/AgCl was applied to the working electrode. As it is shown in Figure 1.B, after the addition of 100 µM of H2O2, the current increases due to the reduction of H2O2. Finally, the selectivity of the sensor was evaluated against ascorbic acid and glucose.In summary, the rGO-based electrochemical sensor was fabricated by inkjet printing graphene oxide with a regular office inkjet printer followed by chemical reduction procedure. The sensor was used to determine the hydrogen peroxide level in aqueous solution. Inkjet-printed rGO electrodes can be used for simple and precise measurement of hydrogen peroxide with high selectivity and sensitivity.

A multifunctional Ni-doped iron pyrite/reduced graphene oxide composite as an efficient counter electrode for DSSCs and as a non-enzymatic hydrogen peroxide electrochemical sensor.

Nickel-doped FeS2/rGO composites were synthesized as multifunctional materials via a facile hydrothermal method. The synthesized materials were characterized with XRD, FESEM, XPS, and TEM-SAED for structural, morphological and chemical studies. To study their electrochemical properties, all the synthesized composites were subjected to cyclic voltammetry tests. The optimum composite revealed high catalytic activity with high peak current density, limiting current, and efficiency of 7.60% for DSSC, which surpassed that of a platinum-based counter electrode (6.69%). The efficiency of the DSSC was significantly supported by interfacial studies and electron lifetime studies, and it exhibited lower charge transfer resistance and higher electron lifetime, respectively. Moreover, the fabricated DSSCs with high efficiency were subjected to transient photo-response studies and showed a stable current response with multiple photo-ON and OFF cycles for a period of 600 s. To broaden the application of the synthesized material, it was used as an electrochemical sensor for the efficient sensing of hydrogen peroxide (H2O2). The sensing electrode was modified with the optimum Ni-doped FeS2/rGO composite, and voltammetric detection was carried out in the hydrogen peroxide concentration range of 4-100 μM. Thus, the synthesized material can be applied in DSSCs and as an electrochemical H2O2 sensor.

A glassy carbon electrode modified with a nanocomposite prepared from Pd/Al layered double hydroxide and carboxymethyl cellulose for voltammetric sensing of hydrogen peroxide.

A Pd/Al layered double hydroxide/carboxymethyl cellulose nanocomposite (CMC@Pd/Al-LDH) was fabricated using carboxymethyl cellulose as a green substrate via co-precipitation method. The synthesized nanocomposite was characterized using different methods such as scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray powder diffraction, transmission electron microscopy, and electrochemical techniques. A glassy carbon electrode (GCE) was then modified with the suspended composite to obtain an electrochemical sensor for hydrogen peroxide (H2O2). The voltammetric (cathodic) current of the modified GCE was measured at -380mV (vs. Ag/AgCl), at the scan rate of 50mV.s-1. Results show a linear dynamic range of 1 to 120μM, and a 0.3 µMlimit of detection (at S/N= 3). Intraday and interday relative standard deviations are in the ranges of 4.9-5.4% and 6.8-7.3%, respectively. The sensor was applied for the determination of H2O2 in basil extracts, milk, and spiked river water samples. The recoveries are between 96.60 and 102.30%. Graphical abstractA Pd/Al layered double hydroxide/carboxymethyl cellulose nanocomposite (CMC@Pd/Al-LDH) was fabricated via co-precipitation method and was characterized using scanning electron microscopy, Energy-dispersive X-ray spectroscopy, X-ray powder diffraction, transmission electron microscopy and electrochemical techniques. CMC@Pd/Al-LDH was used to fabricate H2O2 electrochemical sensor.

The use of CeO2-modified Pt/C catalyst inks for the construction of high-performance enzyme-free H2O2 sensors

In this work, the development of novel enzyme-free electrochemical hydrogen peroxide (H2O2) sensors with high sensitivity and wide linear range is described. The electrochemical sensors were constructed by the physical modification of commercial Pt/C catalysts with CeO2 metal oxide nanoparticles. X-ray diffraction (XRD), transmission electron microscopy (TEM), N2-adsorption, and Raman spectroscopy methods were used to characterize the metal oxide nanoparticles. The CeO2 particles showed fluorite-type structure with the average crystalline size of 13.8nm. Furthermore, the Raman spectroscopy results indicated the presence of high degree of oxygen defects indicating the high redox property of the nanoparticles. The physical surface area of the metal oxide nanoparticles was determined to be 68.8m2g−1. The catalyst inks were prepared by mixing commercial Pt/C and CeO2 nanoparticles with different weight ratios. The analytical performance of the sensors was studied using cyclic voltammetry (CV) and chronoamperometry (CA) methods. The results revealed that the introduction of CeO2 nanoparticles into the catalyst layer improved the sensor performance significantly compared to Pt/C sensors. A high sensitivity of 185.4±6.5μAmM−1cm−2 was obtained from CeO2-modified sensors in a wide linear range of 0.01–30mM. Depending on the obtained results it can be suggested that the novel sensor design holds a great promise for the construction of electrochemical sensors with high sensitivity, selectivity, and wide working window.

Non-enzymatic electrochemical hydrogen peroxide sensing using a nanocomposite prepared from silver nanoparticles and copper (II)-porphyrin derived metal-organic framework nanosheets.

A non-enzymatic hydrogen peroxide (H2O2) electrochemical sensor material was prepared from silver nanoparticles and a 2D copper-porphyrin framework (MOF). The structure and morphology of the nanocomposite were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The results showed that the MOF has a two-dimensional sheet structure, and a large number of Ag NPs are uniformly attached to it. The MOF also acts as a peroxidase mimic. The sensor has excellent catalytic performance in terms of H2O2 reduction. Figures of merit include (a) an electrochemical sensitivity of 21.6μAmM-1cm-2 at a typical working potential of -0.25V (vs. SCE), (b) a detection limit of 1.2μM (at S/N= 3), and (c) a linear response range that extends from 3.7μM to 5.8mM. Compared to other sensors of the same type, the linear range of the sensor is extended by an order of magnitude. Graphical abstract Silver nanoparticles (Ag NPs) were reduced with sodium borohydride (NaBH4) on the surface of copper(II)-porphyrin (Cu-TCPP) nanosheets prepared with the assistance of polyvinylpyrrolidone (PVP). Their synergistic effect improved the performance of H2O2 sensor fabricated by immobilizing Ag NPs/Cu-TCPP nanocomposites on glassy carbon electrodes (GCE).

Pd@CeO2-SnO2 nanocomposite, a highly selective and sensitive hydrogen peroxide electrochemical sensor

In this study, Pd@CeO2-SnO2 nanocomposite was synthesized and various methods such as FE-SEM, TEM, EDS, FT-IR, and XRD were used to characterize the nanocomposite. The electrocatalytic behaviour of the nanocomposite was studied for the reduction of H2O2. After optimization of various experimental parameters including pH, scan rate, rotation rate and potential, the calibration curve was plotted for the reduction reaction of the H2O2 at pHs 7.0 and 8.0. At pH 7.0, the linear range and detection limit were obtained as 0.15–1920 μM and 44 nM, respectively. Also, at pH 8.0, the linear range and detection limit were obtained as 0.12–2170 μM and 36 nM, respectively. In addition, the detection sensitivity of the sensor for the determination of H2O2 at pH 7.0 and 8.0 was 472.40 and 533.07 μA.mM−1. cm-2, respectively. Further, the sensor response to the H2O2 was studied in the presence of various types of potential interference species. The results confirmed the high selectivity of the designed sensor for the reduction of H2O2. Finally, the accuracy and applicability of the H2O2 electrochemical sensor in three different milk samples were evaluated with satisfactory results.

Recent advances in electrochemical nonenzymatic hydrogen peroxide sensors based on nanomaterials: a review

The development of efficient electrochemical hydrogen peroxide (H2O2) sensors has received great attention due to the significance of H2O2 in biological systems and its practical applications in various fields. With the new class of H2O2 sensors, the nonenzymatic detection of the target can provide many attractive characteristics, such as simple fabrication, ultrahigh sensitivity, and excellent stability. Considering the rapid expansion of nonenzymatic H2O2 detection using advanced nanomaterials, an overview of the current state of methods for electrochemical nonenzymatic H2O2 sensors is presented (with 399 refs.). The first part of the review covers the sensors based on the use of nanoparticles consisting of metals, metal oxides/sulfides, and bimetallic nanoparticles/alloys. The next major section discusses sensors that make use of carbon nanomaterials, such as carbon nanotubes, graphene, graphene oxide, carbon dots, and of other carbonaceous materials. Advantages and the intrinsic drawbacks of employing various nanomaterials to detect H2O2 are emphasized.

Electrochemical activity of the polycrystalline cerium oxide films for hydrogen peroxide detection

Abstract Polycrystalline cerium oxide thin films (15 nm) deposited on a glassy carbon substrate were used as an electrode in a mediator-free, non-enzymatic electrochemical sensor for hydrogen peroxide. The electrode surface was characterized by X-ray photoelectron spectroscopy, resonant photoelectron spectroscopy, scanning electron microscopy and atomic force microscopy. The electrode sensitivity, detection limit and pH range of sensor stability were determined by applying electrochemical techniques: cyclic voltammetry and chronoamperometry. It was found that the sensor reactivity to H2O2 is directly related to the presence of electroactive cerium centres of 3+ character on the electrode surface. The Michaelis–Menten mechanism of catalase-like activity of ceria film is suggested as an explanation of the data and discussed. The results confirmed the sensing abilities of technologically well-accessible nanostructured cerium oxide films for hydrogen peroxide detection without using a mediator, i.e. the enzymatic properties of CeO2/GC electrode.

A Facile One-Step Synthesis of Cuprous Oxide/Silver Nanocomposites as Efficient Electrode-Modifying Materials for Nonenzyme Hydrogen Peroxide Sensor.

Cuprous oxide/silver (Cu2O/Ag) nanocomposites were prepared via a facile one-step method and used to construct an electrochemical sensor for hydrogen peroxide (H2O2) detection. In this method, AgNO3 and Cu(NO3)2 were reduced to Cu2O/Ag nanocomposites by glucose in the presence of hexadecyl trimethyl ammonium bromide (CTAB) at a low temperature. The optimum condition was the molar ratio of silver nitrate and copper nitrate of 1:10, the temperature of 50 °C. Under this condition, Cu2O/Ag nanocomposites were obtained with uniformly distributed and tightly combined Cu2O and Ag nanoparticles. The size of Cu2O particles was less than 100 nm and that of Ag particles was less than 20 nm. Electrochemical experiments indicate that the Cu2O/Ag nanocomposites-based sensor possesses an excellent performance toward H2O2, showing a linear range of 0.2 to 4000 μM, a high sensitivity of 87.0 μA mM−1 cm−2, and a low detection limit of 0.2 μM. The anti-interference capability experiments indicate this sensor has good selectivity toward H2O2. Additionally, the H2O2 recovery tests of the sensor in diluted milk solution signify its potential application in routine H2O2 analysis.

Enzyme-free electrocatalytic sensing of hydrogen peroxide using a glassy carbon electrode modified with cobalt nanoparticle-decorated tungsten carbide.

An efficient non-enzymatic electrochemical sensor for hydrogen peroxide (H2O2) was constructed by modifying a glassy carbon electrode (GCE) with a nanocomposite prepared from cobalt nanoparticle (CoNP) and tungsten carbide (WC). The nanocomposite was prepared at low temperature through a simple technique. Its crystal structure, surface morphology and elemental composition were investigated via X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The results showed the composite tobe uniformly distributed and that the CoNP are well attached to the surface of the flake-like WC. Electrochemical studies show that the modified GCE has an improved electrocatalytic activity toward the reduction of H2O2. H2O2 can be selectively detected, best at a working voltage of -0.4V (vs. Ag/AgCl), with a 6.3nM detection limit over the wide linear range from 50nM to 1.0mM. This surpasses previously reported non-enzymatic H2O2 sensors. The sensor was successfully applied to the determination of H2O2 in contact lens solutions and in spiked serum samples. Graphical abstract Schematic presentation of a method for electrochemical sensing of hydrogen peroxide in real samples using cobalt nanoparticle decorated tungsten carbide (WCC) modified glassy carbon electrode (GCE).

A novel enzymatic biosensor for detection of intracellular hydrogen peroxide based on 1-aminopyrene and reduced graphene oxides

An electrochemical sensor for hydrogen peroxide $$(\text {H}_{2}\text {O}_{2})$$ detection was established using 1-aminopyrene (AP) as a linker between horseradish peroxidase (HRP) and reduced graphene oxides (rGO) modified glassy carbon electrode. The AP can combine with HRP via a covalent bond and combine with rGO via $$\uppi $$ - $$\uppi $$ conjugation. The covalent bond linkages can prevent the enzymes leaching of the enzymes and the $$\uppi $$ - $$\uppi $$ conjugate combination can facilitate electrons transfer, which plays synergistic effects to improve the performance of this sensor. The electrochemical activity of the HRP-AP/rGO was described by cyclic voltammetry, alternating current impedance and amperometric techniques. Under the optimal conditions, the biosensor showed a wide linear range from 1.5 $$\upmu $$ M to 28.5 $$\upmu $$ M and a low detection limit of 0.5 $$\upmu $$ M with good stability and high selectivity, confirming that the sensor is well-suited for the detection of $$\text {H}_{2}\text {O}_{2}$$ during biological processes. Using 1-aminopyrene (AP) as a linker between horseradish peroxidase (HRP) and reduced graphene oxides (rGO), an enzymatic hydrogen peroxide ( $$\text {H}_{2}\text {O}_{2})$$ biosensor was established with wide linear range, good stability and high selectivity.

A hollow urchin-like α-MnO2 as an electrochemical sensor for hydrogen peroxide and dopamine with high selectivity and sensitivity.

A hollow urchin-like α-MnO2 material has been synthesized by ahydrothermal method starting from MnSO4·H2Oand (NH4)2S2O8, and byusing silver(I) as the catalyst. It has a hollow morphology with diameters of 5-6μm and consists of densely aligned nanowires, with a 30-40nm width and a 1.5μm length. The diameter of the cavities and the thickness of the shell are about 1.2μm and 300nm, respectively. The material was placed on a glassy carbon electrode (GCE), and electrochemical experiments showed the respective sensor to possess good stability and reproducibility. The modified GCE displays response to both hydrogen peroxide (H2O2) and dopamine (DA) at working potentials of -0.40V and +0.4V, respectively (both versus SCE). H2O2 can be detected with an 80nM detection limit, and DA with a 12nM detection limit (at S/N = 3). Graphical abstract Schematic presentation of synthesis of a hollow urchin-like α-MnO2, which taking MnSO4.H2O and (NH4)2S2O8 as raw materials and was further used to construct an electrocatalytic sensor for hydrogen peroxide and dopamine with low detection limit, desirable selectivity and sensitivity.

Preparation of modified glassy carbon electrode by the use of titanium oxide, copper and palladium nanoparticles and its application for the electrocatalytic and photelectrocatalytic reduction of hydrogen peroxide

A new electrochemical sensor for hydrogen peroxide (H2O2) determination was fabricated based on less expensive and simple layer-by-layer method. The morphological and elemental characteristics of palladium, copper and titanium oxide nanoparticles modified glassy carbon electrode (GCE) were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. The electrochemical behaviors of H2O2 on constructed sensor were investigated by cyclic voltammetry and amperometry techniques. By integration of the palladium, copper and titanium oxide nanoparticles into the nanocomposite, the constructed nanocomposite illustrated good synergistic effect in reduction of H2O2, thereby resulting in the higher cathodic peak current and very reduced over potential. The sensor displays a fast response time less than 2 s with a linear range from 0.05 µM to 0.1 M and detection limit of 16.0 nM (S/N = 3). Moreover, the photoelectrocatalytic capability of the proposed modified electrode was explored in dark and under light irradiation conditions. The catalytic current significantly increased under illumination condition and it comes back to its original value by turning off the light irradiation. This result indicates the stable photo-induced catalytic behavior of the constructed sensor. The resulting sensor was successfully used to detection of hydrogen peroxide in real samples.