Non-enzymatic Hydrogen Peroxide Research Articles

A novel catalase mimicking nanocomposite of Mn(II)-poly-L-histidine-carboxylated multi walled carbon nanotubes and the application to hydrogen peroxide sensing

In this work, a novel enzyme-mimicking nanocomposite of Mn(II)-poly-L-histidine (PLH) functionalized carboxylated multi walled carbon nanotubes (CMWCNTs) was designed and synthesized. Based on the catalase-like activity of the nanocomposite, a non-enzymatic hydrogen peroxide (H2O2) biosensor was then established and explored for H2O2 electrochemical detection. The nanocomposite was characterized by Fourier transform infrared spectra, Raman spectroscopy, and transmission electron microscopy. Due to the enlarged effective surface area and the efficient electrocatalytic activity of the Mn(II)-PLH redox-active units, the obtained Mn(II)-PLH-CMWCNT electrode showed excellent electrocatalytic performance toward H2O2 disproportionation. Under the selected optimum conditions, the prepared biosensor exhibited highly sensitive response toward H2O2, and the response current had a good linear relationship between the response currents and H2O2 concentrations in the range of 0.002–1.0 mM, a low detection limit of 0.5 μM and a sensitivity of 464.18 μA mM-1 cm-2. With the good stability, reproducibility and selectivity, the proposed biosensor was successfully applied to the determination of H2O2 in real-life samples, and showed satisfactory results. In summary, the Mn(II)-PLH-CMWCNT nanocomposite could be a promising enzyme-mimicking nanomaterial for the researches of electrocatalysis, biosensing and relevant fields.

Thin layers formed by the oriented 2D nanocrystals of birnessite-type manganese oxide as a new electrochemical platform for ultrasensitive nonenzymatic hydrogen peroxide detection

Thin layers formed by the arrays of the vertically oriented 2-dimensional nanocrystals of Birnessite-type manganese oxide CuxMnO2∙nH2O were synthesized for the first time by the reaction of gaseous ozone with the surface of aqueous solutions of manganese (II) acetate and copper (II) acetate salts mixture. The obtained layers were placed onto the surface of indium tin oxide (ITO)–coated glass electrodes and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), X-Ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The electrochemical performance of the layers was examined by cyclic voltammetry (CV). It was found that the synthesized structures are formed by the 2D nanocrystals with the thickness of 3–6 nm. The atomic concentration of copper x depends on the ratio of Cu(CH3COO)2 and Mn(CH3COO)2 solution concentrations and can be as much as 0.35. The obtained layers were tested as the electrochemical platform for nonenzymatic hydrogen peroxide sensing. It was shown that the electrode can provide an ultrasensitive H2O2 determination with the limit of detection of 0.4 nМ and linear concentration range that lies in the region of nanomolar concentrations. We assume that the observed effects are due to the morphology of the synthesized layers, which ensures maximum contact of the analyte with the active sites of 2D nanocrystals of CuxMnO2 ∙ nH2O. Comparison of the obtained analytical characteristics with the literature data indicates the good prospects of the synthesized nanomaterial for its use as a working electrode for nonenzymatic H2O2 sensor.

Tuning polyelectrolyte-graphene interaction for enhanced electrochemical nonenzymatic hydrogen peroxide sensing

Herein, tuning polyelectrolyte-graphene interaction was demonstrated to enhance electrocatalytic activity for non-enzymatic hydrogen peroxide detection. The introduction of positively charged poly(diallyldimethylammonium chloride) (PDDA) onto graphene surface not only prevent the aggregation of graphene sheets through electrostatic repulsion but also create net positive charge on adjacent carbon atoms in the graphene due to the occurrence of the intermolecular charge transfer by virtue of the robust electron-withdrawing ability of PDDA. Notably, we revealed the influence of the adsorbed polyelectrolytes on the redox of H2O2 and the related mechanism was discussed in detail. In a word, the catalytic activities of the graphene could be effectively tuned via the induction of the polyelectrolytes with different attributes. It was expected that this finding could be favorable for the tuning graphene electronic structure and further developing the novel graphene-based electrochemical sensing platforms.

Construction and Application of a Non-Enzyme Hydrogen Peroxide Electrochemical Sensor Based on Eucalyptus Porous Carbon.

Natural eucalyptus biomorphic porous carbon (EPC) materials with unidirectional ordered pores have been successfully prepared by carbonization in an inert atmosphere. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) were employed to characterize the phase identification, microstructure and morphology analysis. The carbon materials were used to fabricate electrochemical sensors to detect hydrogen peroxide (H2O2) without any assistance of enzymes because of their satisfying electrocatalytic properties. It was immobilized on a glassy carbon electrode (GCE) with chitosan (CHIT) to fabricate a new kind of electrochemical sensor, EPC/CHIT/GCE, which showed excellent electrocatalytic activity in the reduction of H2O2. Meanwhile, EPC could also promote electron transfer with the help of hydroquinone. The simple and low-cost electrochemical sensor exhibited high sensitivity, and good operational and long-term stability.

A Novel Non-Enzymatic Electrochemical Hydrogen Peroxide Sensor Based on a Metal-Organic Framework/Carbon Nanofiber Composite.

A co-based porous metal-organic framework (MOF) of zeolitic imidazolate framework-67 (ZIF-67) and carbon nanofibers (CNFs) was utilized to prepare a ZIF-67/CNFs composite via a one-pot synthesis method. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) were employed to investigate the morphology, structure, and composition of the resulting composite. A novel high-performance non-enzymatic electrochemical sensor was constructed based on the ZIF-67/CNFs composite. The ZIF-67/CNFs based sensor exhibited enhanced electrocatalytic activity towards H2O2 compared to a pure ZIF-67-based sensor, due to the synergistic effects of ZIF-67 and CNFs. Meanwhile, chronoamperometry was utilized to explore the detection performance of the sensor. Results showed the sensor displayed high-efficiency electrocatalysis towards H2O2 with a detection limit of 0.62 μM (S/N = 3), a sensitivity of 323 µA mM−1 cm−2, a linear range from 0.0025 to 0.19 mM, as well as satisfactory selectivity and long-term stability. Furthermore, the sensor demonstrated its application potential in the detection of H2O2 in food.

Fabrication of silver nanoparticles in titanium dioxide/poly(vinyl alcohol) alternate thin films: A nonenzymatic hydrogen peroxide sensor application

Silver nanoparticles (AgNPs) were readily synthesized in TiO2/poly(vinyl alcohol) (PVA) ultrathin films, which is alternately assembled with Ti(O-nBu)4 and PVA via a surface sol-gel process. The photochemical reduction of as-embedded Ag+ ions in the film led to the formation of well-controllable AgNPs in size, distribution and electrochemical properties. AgNP-immobilized TiO2/PVA films were characterized by quartz crystal microbalance measurements, ultraviolet–visible (UV–vis) spectroscopy, atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and electrochemical measurements. The increase in thickness of TiO2/PVA hybrid films led to an increase in the surface plasmon resonance peak, showing a blueshift in UV–vis absorption. As the alternate cycles of TiO2/PVA thin film increased (3.5-, 5.5-, and 10.5-cycle), the sizes of prepared AgNPs gradually decreased (9.3, 8.0, and 6.2 nm, respectively) and the distributions of the AgNPs become narrower, correspondingly. Regarding its electrochemical properties, the TiO2/PVA hybrid films showed a well-defined reversible redox system on gold electrodes (GEs), as observed by a pair of current peaks, and further exhibited electrocatalytic activity, and a low limit of detection (LOD) for hydrogen dioxide (H2O2). A lower cycle of thinner hybrid film, 1.5-cycle TiO2/PVA, showed relatively higher electrochemical and amperometric responses than those of 3.5-, 5.5-, and 10.5-cycle films. Based on the amperometric response of the AgNP-incorporated 1.5-cycle TiO2/PVA film, the linear regression equation was acquired as I(μA) = −0.0481 [H2O2] (μM) + 0.4099, with a correlation coefficient of 0.9872. Thus, the significant sensitivity to H2O2 up to 0.0481 μA/μM and LOD of 0.11 μM were achieved, respectively.

Layer-by-layer chitosan-decorated pristine graphene on screen-printed electrodes by one-step electrodeposition for non-enzymatic hydrogen peroxide sensor

Layer-by-layer chitosan-decorated pristine graphene on screen-printed electrodes was achieved by one-step electrodeposition method and an enzyme-free hydrogen peroxide electrochemical biosensor was fabricated for its application. Negatively charged pristine graphene absorbed with positively charged chitosan by electrostatic interactions was electrodeposited on the electrodes. The successful immobilization of pristine graphene was confirmed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and electrochemical characterizations. The graphene-chitosan volume ratio and cyclic voltammetry scan cycles during the electrodeposition process were optimized. The resulting hydrogen peroxide biosensors showed a 178 times improved sensitivity and exhibited two wide linear detection ranges from 20 μM to 20 mM and from 20 mM to 60 mM. The biosensors also showed a good reproducibility, stability, selectivity and could be used in real samples detection. The superior electrochemical performance of graphene-chitosan was attributed to the preservation of excellent properties of pristine graphene, and the formation of layer-by-layer structure with high surface area. The proposed strategy of direct immobilization of pristine graphene can be extended for the immobilization of other nanomaterials and biomolecules.

Non-enzymatic electrochemical hydrogen peroxide biosensor based on reduction graphene oxide-persimmon tannin‑platinum nanocomposite

Hydrogen peroxide (H2O2) is one of the most universal and essential ingredients in distinct biological tissues. Herein, a novel non-enzymatic sensor based on reduction graphene oxide-persimmon tannin‑platinum nanocomposite (RGO-PT-Pt) was exploited for H2O2 detection. RGO-PT-Pt nanocomposite was prepared by reduction procedure with ascorbic acid as reducing agent and characterized by Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV–vis) and Fourier infrared spectroscopy (FT-IR). Taking advantage of high electro-catalytic efficiency of Pt nanoparticles, high electronic conductivity and large surface area of RGO, and significant adsorption ability of PT on metal ions and its prevention of agglomeration to promote RGO dispersion, RGO-PT-Pt nanocomposite revealed better catalytic ability towards H2O2 via a synergistic effect. Under the optimal conditions, the RGO-PT-Pt non-enzymatic biosensor exhibited outstanding electrocatalytic activity towards H2O2 reduction. The amperometric response demonstrated a linear relationship with H2O2 concentration from 1.0 to100 μM with the correlation coefficient of 0.9931. The limit of detection was 0.26 μM (S/N = 3) and the response time was 3 s. Furthermore, the fabricated sensor exhibited a practical applicability in the quantification of H2O2 in human serum samples with an excellent recovery rate. Due to excellent performance such as fast response time, low detection limit, high stability and selectivity, the RGO-PT-Pt non-enzymatic biosensor has potential application in clinical diagnostics.

Green Preparation of Ag-Au Bimetallic Nanoparticles Supported on Graphene with Alginate for Non-Enzymatic Hydrogen Peroxide Detection.

In this work, a facile, environmentally friendly method was demonstrated for the synthesis of Ag-Au bimetallic nanoparticles (Ag-AuNPs) supported on reduced graphene oxide (RGO) with alginate as reductant and stabilizer. The prepared Ag-AuNPs/RGO was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results indicated that uniform, spherical Ag-AuNPs was evenly dispersed on graphene surface and the average particle size is about 15 nm. Further, a non-enzymatic sensor was subsequently constructed through the modified electrode with the synthesized Ag-AuNPs/RGO. The sensor showed excellent performance toward H2O2 with a sensitivity of 112.05 μA·cm−2·mM−1, a linear range of 0.1–10 mM, and a low detection limit of 0.57 μM (S/N = 3). Additionally, the sensor displayed high sensitivity, selectivity, and stability for the detection of H2O2. The results demonstrated that Ag-AuNPs/RGO has potential applications as sensing material for quantitative determination of H2O2.

Microstructured prealloyed Titanium-Nickel powder as a novel nonenzymatic hydrogen peroxide sensor

At present, commercial pure Titanium (Ti) and microstructured pre-alloyed Titanium-Nickel (TiNi) powders are employed as a sensitive electrochemical hydrogen peroxide (H2O2) sensor. Surface characterization of these materials are performed by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical characterization is achieved via cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) on Ti and TiNi modified glassy carbon electrode (GCE). The electrochemical behavior of H2O2 at the pure Ti/GCE and microstructure pre-alloyed TiNi/GCE are studied by CV in 0.1 M phosphate buffer solution (PBS) containing as the supporting electrolyte. In addition, CA is employed for the determination of H2O2 at the applied potential of 0 V vs. Ag/AgCl. The sensor has a linear response range of 0.5–17.5 mM with a sensitivity of 280 µA mM−1 cm−2. Moreover, the limit of detection (LOD) and limit of quantification (LOQ) are 0.5 µM and 1.7 µM, respectively. The electrochemical sensor exhibits fast and selective responses to H2O2 concentration. The applicability of the sensor is checked using a hair coloring as a real sample with satisfactory results.

Robust Nanocomposite of Nitrogen-Doped Reduced Graphene Oxide and MnO2Nanorods for High-Performance Supercapacitors and Nonenzymatic Peroxide Sensors

The urgent demand of sustainable energy systems and reliable sensing devices has fostered the development of cost-effective, multifunctional electrode material based platforms. In this work, we have demonstrated the bifunctionality of nitrogen-doped reduced graphene oxide-MnO2 nanocomposite (NRGO-MnO2), toward two most diverse and challenging applications: (i) supercapacitor and (ii) peroxide sensor, which was synthesized by a facile one-pot hydrothermal method. The electrochemical investigations revealed its high specific capacitance (648 F g–1 at 1.5 A g–1) with remarkable rate performance (retains 80.20% up to 10 A g–1) and long-term cyclic efficiency. Additionally, it can detect peroxide rapidly (2 s), with high sensitivity (2081 μAmM–1 cm–2) and a noteworthy detection limit (24 nM) in a wide dynamic range (0.4–121.2 μM). Fascinating features such as the distinguished selectivity, repeatability, and operational stability suggests its potency to be an ideal electrode for peroxide sensors. Finally, the ...

Non-enzymatic electrochemical hydrogen peroxide detection using MoS2- Interconnected porous carbon heterostructure

Sensitive and non-enzymatic electrochemical hydrogen peroxide (H2O2) sensor was fabricated using molybdenum disulphide (MoS2)-Interconnected porous carbon (ICPC) heterostructure. The structural properties of synthesized MoS2, ICPC and MoS2-ICPC materials were examined by various spectroscopy and microscopy techniques. These results confirmed that the support matrix play a crucial role for the formation of different size of MoS2. The structure of MoS2 altered to nanosized while growing on the support matrix. The electrochemical H2O2 sensing characteristics of MoS2-ICPC composite material exhibited superior activity than individual MoS2 and ICPC materials. The results concluded that the interconnected porous carbon might stimulate the structural modification of MoS2 with enhance exposed active edge sites, which is responsible for higher electrochemical activity. The composite material exhibited a detection limit of 11.8 μM H2O2 with higher sensitivity, selectivity, and long-term stability. These results open a novel way to build MoS2-ICPC material for active electrochemical sensor applications.

An enzyme-free hydrogen peroxide sensor for evaluation of probiotic potential of Enterococcus faecium

A novel strategy to realize a non-enzymatic hydrogen peroxide (H2O2) sensor based on reduced graphene oxide dispersed in ionic liquid for monitoring the exogenous production of H2O2 by Enterococcus faecium is presented in this work. The electrodes functionalization steps were studied by electrochemical impedance spectroscopy and cyclic voltammetry. FT-IR spectroscopy and scanning electron microscopy were used to characterize the electrode materials. The amperometric measurements on reduced graphene oxide-ionic liquid modified screen-printed electrode showed that the modified electrodes can be used to detect H2O2 with a high sensitivity of 1,484 ± 25 μA mM−1 cm-2 and a low detection limit of 0.1 μM (for a signal-to-noise ratio of 3). In addition, the electrodes exhibited an excellent reproducibility and long-term stability as well as negligible interference from ascorbic acid, citric acid, urea and creatinine. The sensor was successful in monitoring the H2O2 production from Enterococcus faecium 2980 clinical strain cultivated in anaerobic and aerobic conditions. The good correlation of the proposed sensor with spectrometric method indicates its very good potential in clinical and biochemical applications.

Fabrication of Highly Sensitive Nonenzymatic Electrochemical H₂O₂ Sensor Based on Pt Nanoparticles Anchored Reduced Graphene Oxide.

A highly sensitive nonenzymatic hydrogen peroxide (H2O2) sensor was fabricated using platinum nanoparticles decorated reduced graphene oxide (Pt/rGO) nanocomposite. The Pt/rGO nanocomposite was prepared by single-step chemical reduction method. Nanocomposite was characterized by various analytical techniques including Raman spectroscopy, X-ray diffraction, field emission scanning electron microscope and high-resolution transmission electron microscopy. Screen printed electrodes (SPEs) were fabricated and the nanocomposite was cast on the working area of the SPE. Cyclic voltammetry and amperometry demonstrated that the Pt/rGO/SPE displayed much higher electrocatalytic activity towards the reduction of H2O2 than the other modified electrodes. The sensor exhibited wide linear detection range (from 10 μM to 8 mM), very high sensitivity of 1848 μA mM-1 cm-2 and a lower limit of detection of 0.06 μM. The excellent performance of Pt/rGO/SPE sensor were attributed to the reduced graphene oxide being used as an effective matrix to load a number of Pt nanoparticles and the synergistic amplification effect of the two kinds of nanomaterials. Moreover, the sensor showed remarkable features such as good reproducibility, repeatability, long-term stability, and selectivity.

One-step synthesis highly sensitive non-enzyme hydrogen peroxide sensor based on prussian blue/polyaniline/MWCNTs nanocomposites

We have prepared a novel and sensitive electrochemical hydrogen peroxide sensor which is based on a glassy carbon electrode modified with prussian blue/polyaniline/multiwalled carbon nanotubes (PB/PANI/MWCNTs) nanocomposites. The synthetic process was very simple and facile through a one-step approach, while aniline plays the role of both the precursor of PANI and the reductant for FeCl3-K3[Fe(CN)6]. The as-prepared nanocomposites were characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. Besides, electrochemical techniques were used to evaluate the electrochemical performance of the PB/PANI/MWCNTs nanocomposite-modified electrode towards H2O2. The experiment results successfully confirmed that the PB nanoparticles were anchored on the surface of PANI/MWCNTs uniformly. The influence of various experimental parameters on the detection of H2O2 was studied in detail, as well. Under optimum conditions, the developed H2O2 sensor had a linear response in the concentration range of 0.005–1.03 mM with a high sensitivity of 4018.57 mA mM−1 cm−2 and a detection limit of 1.7 mM. In addition, the fabricated H2O2 sensor showed excellent selectivity, reproducibility, and stability.

A novel nonenzymatic hydrogen peroxide amperometric sensor based on Pd@CeO2-NH2 nanocomposites modified glassy carbon electrode

Herein, (3-aminopropyl)triethoxysilane functionalized cerium (IV) oxide (CeO2-NH2) supported Pd nanoparticles were synthesized. The nanocomposites were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and High-resolution transmission electron microscopy (HRTEM). The Pd@CeO2-NH2 showed better electrocatalytic response to the reduction of H2O2 than CeO2-NH2. The fabricated sensor exhibited two linear responses to the reduction of H2O2. The first one was from 0.001 to 3.276 mM with 0.47 μM of a limit of detection (LOD) (S/N = 3) and excellent sensitivity of 440.72 μA mM−1 cm−2 and the second one was from 3.276 to 17.500 mM with the sensitivity of 852.65 μA mM−1 cm−2 in the optimum conductions. Also, the sensor exhibited 91% of electrocatalytic activity toward H2O2 after having been used for 30 days and the reproducibility was also satisfactory. The sensor response to H2O2 was not affected by ascorbic acid, fructose, glycine, dopamine, arginine, mannose, glucose, uric acid, Mg+2, Ca+2, and phenylalanine at the studied potential. Also, the fabricated sensor was used to determine H2O2 in milk samples. The results show that the constructed sensor can be a promising devise for the determination of H2O2 in real samples.

Preparation of Partially Unzipped Carbon Nanotube/Ag (PUCNTs/Ag) Nanocomposite and Its Application for H₂O₂ Based Non-Enzymatic Sensor.

In the present work, the nanocomposite of the silver nanoparticles decorated partially unzipped carbon nanotubes (PUCNTs) (PUCNTs/Ag) was fabricated by in situ method, and its application as a sensitive non-enzymatic hydrogen peroxide (H2O2) sensor was then explored correspondingly. The measurements of transmission electron microscopy (TEM), fourier transform infrared (FTIR) spectroscopy and ultraviolet visible (UV-vis) absorption spectrum proved that the PUCNTs/Ag composite has been successfully prepared and the Ag nanoparticles dispersed on the surface of the PUCNTs and entered the inner of unzipped MWCNTs. Cyclic voltammetric (CV) measurement indicated that the PUCNTs/Ag nanocomposite showed the well-defined redox characteristics in 0.1 M phosphate buffer solution (PBS, pH = 7.5), and under the optimized experimental conditions, the current response of the as-obtained sensor towards electrochemical oxidation of H2O2 was linear with the concentration of H2O2 in the range of 0.0419 mM to 87 mM (R = 0.997) in the solution of 0.1 M PBS (pH = 7.5) at the applied potential of 0 V. The detection limit was 1 μM with the sensitivity calculated as 1.115 × 103 μA · M-1 · cm-2 and the fast response achieved within 3 s. The constructed non-enzymatic sensor is one of the promising candidates due to it's good sensitivity, selectivity, and reproducibility.

High-performance Cu nanoparticles/three-dimensional graphene/Ni foam hybrid for catalytic and sensing applications

A novel hybrid of Cu nanoparticles/three-dimensional graphene/Ni foam (Cu NPs/3DGr/NiF) was prepared by chemical vapor deposition, followed by a galvanic displacement reaction in Ni- and Cu-ion-containing salt solution through a one-step reaction. The as-prepared Cu NPs/3DGr/NiF hybrid is uniform, stable, recyclable and exhibits an extraordinarily high catalytic efficiency for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with a reduction rate constant K = 0.056 15 s−1, required time ∼30 s and excellent sensing properties for the non-enzymatic amperometric hydrogen peroxide (H2O2) with a linear range ∼50 μM–9.65 mM, response time ∼3 s, detection limit ∼1 μM. The results indicate that the as-prepared Cu NPs/3DGr/NiF hybrid can be used to replace expensive noble metals in catalysis and sensing applications.

Three-dimensional porous reduced graphene oxide decorated with MoS2 quantum dots for electrochemical determination of hydrogen peroxide

Three-dimensional (3D) graphene-based nanomaterials have shown wide applications in electrochemical fields such as biosensors. In this study, we displayed a simple fabrication of 3D structural reduced graphene oxide (3D structural RGO) decorated with molybdenum disulfide quantum dots (MoS2QDs) through a three-step reaction process. With its abundant raw materials, this strategy is economic and non-toxic. Various characterization techniques were utilized to characterize the morphologies of the synthesized MoS2QDs, graphene oxide (GO), and 3D structural RGO-MoS2QDs composites. Simultaneously, X-ray photoelectron spectroscopy was applied to characterize the structure and properties of composites. In order to understand the effects of the reaction period on the structure of 3D structural RGO-MoS2QDs, a series of samples with various reaction periods were prepared for morphological characterization. Finally, the fabricated 3D structural RGO-MoS2QDs composites were used to modify a glassy carbon electrode as an electrochemical non-enzymatic hydrogen peroxide (H2O2) sensor. The obtained results indicate that the fabricated electrochemical H2O2 sensor exhibits a wide detection range (0.01–5.57 mM), low detection limit (1.90 μM), good anti-interference performance, and long-time stability (18 days).

Preparation of Nano Au and Pt Alloy Microspheres Decorated with Reduced Graphene Oxide for Nonenzymatic Hydrogen Peroxide Sensing.

The flourish of nanotechnology has brought new vitality to the research and development of electrochemical sensing materials. In this work, we successfully synthesized Nano Au and Pt alloy microspheres decorated with reduced graphene oxide (RGO/nAPAMSs) by a simple, facile, and eco-friendly one-step reduction strategy for the fabrication of highly sensitive nonenzymatic H2O2 sensing interfaces. Energy-dispersive X-ray spectroscopy mapping (EDX mapping), energy-dispersive X-ray spectroscopy analysis (EDX), transmission electron microscopy (TEM), Fourier transform infrared spectrum (FT-IR), and X-ray diffraction spectrum (XRD) were employed to characterize RGO/nAPAMSs from a microscopic perspective. The results of cyclic voltammetry and chronoamperometry exhibited excellent electrochemical behaviors toward H2O2, with a rapid response time within 5 s, remarkable sensitivity of 1117.0 μA mM-1 cm-2, wide linear range of 0.005 to 4.0 mM and lower detection limit of 0.008 μM (S/N = 3), which provide RGO/nAPAMS not only a promising prospect for the quantitative detection of H2O2 but also a potential application in other fields of sensors. Moreover, further analysis showed the principles of the superior H2O2 sensing performance of RGO/nAPAMSs. This discovery provides a significant contribution to future study in nonenzymatic H2O2 sensing based on Nano Pt, Nano Au noble metal electrocatalysts.