Detection Of Peroxide Research Articles

Boosting Photo-Electro-Fenton Process Via Atomically Dispersed Iron Sites on Graphdiyne for InVitro Hydrogen Peroxide Detection.

Hydrogen peroxide (H2 O2 ) is essential in oxidative stress and signal regulation of organs of animal body. Realizing in vitro quantification of H2 O2 released from organs is significant, but faces challenges due to short lifetime of H2 O2 and complex bio-environment. Herein, rationally designed and constructed a photoelectrochemical (PEC) sensor for in vitro sensing of H2 O2 , in which atomically dispersed iron active sites (Hemin) modified graphdiyne (Fe-GDY) serves as photoelectrode and catalyzes photo-electro-Fenton process. Sensitivity of Fe-GDY electrode is enhanced 8 times under illumination compared with dark condition. The PEC H2 O2 sensor under illumination delivers a wide linear range from 0.1 to 48 160µm and a low detection limit of 33nm, while demonstrating excellent selectivity and stability. The high performance of Fe-GDY is attributed to, first, energy levels matching of GDY and Hemin that effectively promotes the injection of photo-generated electrons from GDY to Fe3+ for reduced Fe2+ , which facilitates the Fe3+ /Fe2+ cycle. Second, the Fe2+ actively catalyzes H2 O2 to OH- through the Fenton process, thereby improving the sensitivity. The PEC sensor demonstrates in vitro quantification of H2 O2 released from different organs, providing a promising approach for molecular sensing and disease diagnosis in organ levels.

Colorimetric and fluorescent dual-signals probes for naked-eye detection of hydrogen peroxide and applications in milk samples and in vivo

Excessive residual hydrogen peroxide (H2O2) disinfectant in food is harmful to human health. Therefore, it is necessary to develop efficient detection methods for H2O2 detection. In this work, we designed and synthesized five D-A molecules 3a-3e by introducing electron-donor substituents (–OCH3 and –CH3) to the electron-acceptor dicyanoisophorone skeleton in order to find out the suitable probes for H2O2 detection. Among them, two promising probes, 3a and 3c, are screened out according to structure-property relationships. Based on the principle of intramolecular charge transfer (ICT), 3a and 3c express colorimetric and fluorescent dual-signals towards H2O2 with low detection limits (0.20 μM and 0.14 μM) and rapid response (within 20 mins). The reaction mechanism between probes and H2O2 is determined by 1H NMR and HRMS. Density functional theory (DFT) calculations are measured to study the regulation mechanism of structure adjustment on probs performance. Furthermore, a smartphone RGB analysis is utilized as a portable platform for the quantitative detection of H2O2 without complicated instruments, indicating a high efficiency and on-site detection method for H2O2. In addition, probes are applied to detect H2O2 in milk samples, HepG-2 cells and zebrafish, suggesting the promising applications in food samples and physiological systems.

Fabrication of Nitrogen-containing Nanocarbons for the Detection of Hydrogen Peroxide Utilizing Layered Silicate Magadiite as a Template

Fabrication of Nitrogen-containing Nanocarbons for the Detection of Hydrogen Peroxide Utilizing Layered Silicate Magadiite as a Template

Versatile FeMoOv nanozyme bipolar electrode electrochemiluminescence biosensing and imaging platform for detection of H2O2 and PSA

In this work, a unique FeMoOv nanozyme-bipolar electrode (NM-BPE) electrochemiluminescence (ECL) biosensing and imaging platform was proposed for the first time to realize sensitive detection of target hydrogen peroxide (H2O2) and prostate specific antigen (PSA). Considering the advantage that the cathode and anode poles of the bipolar electrode (BPE) can be modified respectively, this work was carried out using anode equipped with ECL reagent bipyridine ruthenium (Ru(bpy)32+), and cathode equipped with the Fe-doped molybdenum oxide/Au nanoparticles (FeMoOv/AuNPs) with excellent peroxidase (POD) and catalase (CAT)-like activity. Because FeMoOv/AuNPs show efficient enzyme catalysis effect and can greatly promote the decomposition of H2O2, thus the electron transfer rate in the NM-BPE system would be much accelerated to enhance the ECL signal of Ru(bpy)32+. Based on this principle, this work not only realized sensitive detection of H2O2, but also ingeniously designed an sandwich immunosensor using FeMoOv/AuNPs as recognition probe to mediate the ECL response on the anode, achieving highly sensitive detection of PSA. Furthermore, a unique mobile phone ECL imaging system was developed for assay of PSA at different concentrations, which opened a new portable imaging sensing device for bioassays. This work was the first time to combine nanozymes with bipolar electrodes for ECL analysis and imaging, which not only broadened the applications of nanozymes, but also pioneered the new joint ECL research technique of bipolar electrode and ECL imaging in bioassays, showing great application prospect for multiple detection of proteins, nucleic acids and cancer cells.

Fluorescent sensor based on PtS2-PEG nanosheets with peroxidase-like activity for intracellular hydrogen peroxide detection and imaging

Hydrogen peroxide (H2O2) is produced in living organisms and is involved in a variety of redox-regulated processes. Therefore, the detection of H2O2 is important for tracing the molecular mechanisms of some biological events. Here, we demonstrated for the first time the peroxidase activity of PtS2-PEG NSs under the physiological conditions. PtS2 NSs were synthesized by mechanical exfoliation followed by functionalization with polyethylene glycol amines (PEG-NH2) to improve their biocompatibility and physiological stability. Fluorescence was generated by catalyzing the oxidation of o-phenylenediamine (OPD) by H2O2 in the presence of the PtS2 NSs. The proposed sensor had a limit of detection (LOD) of 248 nM and a detection range of 0.5–50 μM in the solution state, which was better than or comparable to previous reports in the literature. The developed sensor was further applied for the detection of H2O2 released from cells as well as for imaging studies. The results show that the sensor is promising for future applications in clinical analysis and pathophysiology.

Analytical Methods for Oxalate Quantification: The Ubiquitous Organic Anion

Oxalate is a divalent organic anion that affects many biological and commercial processes. It is derived from plant sources, such as spinach, rhubarb, tea, cacao, nuts, and beans, and therefore is commonly found in raw or processed food products. Oxalate can also be made endogenously by humans and other mammals as a byproduct of hepatic enzymatic reactions. It is theorized that plants use oxalate to store calcium and protect against herbivory. Clinically, oxalate is best known to be a major component of kidney stones, which commonly contain calcium oxalate crystals. Oxalate can induce an inflammatory response that decreases the immune system's ability to remove renal crystals. When formulated with platinum as oxaliplatin (an anticancer drug), oxalate has been proposed to cause neurotoxicity and nerve pain. There are many sectors of industry that are hampered by oxalate, and others that depend on it. For example, calcium oxalate is troublesome in the pulp industry and the alumina industry as it deposits on machinery. On the other hand, oxalate is a common active component of rust removal and cleaning products. Due to its ubiquity, there is interest in developing efficient methods to quantify oxalate. Over the past four decades, many diverse methods have been reported. These approaches include electrochemical detection, liquid chromatography or gas chromatography coupled with mass spectrometry, enzymatic degradation of oxalate with oxalate oxidase and detection of hydrogen peroxide produced, and indicator displacement-based methods employing fluorescent or UV light-absorbing compounds. Enhancements in sensitivity have been reported for both electrochemical and mass-spectrometry-based methods as recently as this year. Indicator-based methods have realized a surge in interest that continues to date. The diversity of these approaches, in terms of instrumentation, sample preparation, and sensitivity, has made it clear that no single method will work best for every purpose. This review describes the strengths and limitations of each method, and may serve as a reference for investigators to decide which approach is most suitable for their work.

Abstract 6050: Analysis of diverse metabolic pathways using bioluminescent cell-based assays

Abstract Cellular energy metabolism is a complex system of many interconnected metabolic pathways that govern both cell health and function. Cancer cells are adept at quickly switching between metabolic pathways to adapt to nutrient limitations in the environment, enhancing their growth advantages while negatively impacting other cells in the tumor microenvironment such as immune cells. To facilitate metabolic characterization of cancer cells, we developed assays for detection of metabolites involved in key pathways, such as glycolysis and glutaminolysis, using a bioluminescent NADH detection technology coupled to specific dehydrogenases. We have now extended these assays to include metabolites involved in glycogen, lipid, ketone body and amino acid metabolism, as well as intermediates in the TCA cycle such as malate, isocitrate, and 2-hydroxyglutarate. A second core bioluminescent hydrogen peroxide detection system was also used to develop an assay for pyruvate. Here we describe the use of these assays to measure metabolite levels in cell lysates and cell culture media collected from cancer cell lines plated in 96- or 384-well plates and in 2D or 3D cultures. Changes in metabolite levels were monitored in response to altered media composition and drug treatments. Levels were also compared between different cell lines. In comparative studies of glioblastoma cell lines, 2-hydroxyglutarate production was higher in cells expressing mutant isocitrate dehydrogenase. By reconfiguring the NADH detection technology to measure cellular enzyme activity rather than metabolite levels, we were able to detect activity of dehydrogenases that participate in the glycolysis pathway, the TCA cycle, and pentose phosphate pathway. Assays for cellular malate dehydrogenase, isocitrate dehydrogenase and other dehydrogenase enzymes were sensitive, requiring ≤ 400 lysed cells per assay. The expanded collection of bioluminescent assays provides a way to quickly characterize the metabolic states and behaviors of cancer cells to help identify pathways that may present therapeutic targets. Citation Format: Donna Leippe, Natasha Karassina, Mike Valley, Kayla Sylvester, Jolanta Vidugiriene. Analysis of diverse metabolic pathways using bioluminescent cell-based assays [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6050.

Simultaneous electrochemical detection of dopamine and hydrogen peroxide based on bifunctional microelectrode array

Simultaneous electrochemical detection of dopamine and hydrogen peroxide based on bifunctional microelectrode array

Optical bi-enzyme-titania biosensor system: A new way to detect lactose

Lactose concentration is a key parameter for assessing the quality of raw and processed milk and identifying abnormal milk. Current methods for lactose determination are laborious, time-consuming and oftentimes require skilled lab workers, expensive equipment, and special reagents. In this study, an optical biosensor system based on nanosized titanium dioxide (TiO2) is presented for routine measurement of lactose in milk without sample preparation. TiO2 was obtained via sol-gel synthesis and characterized using dynamic light scattering, microelectrophoresis, X-ray diffraction, transmission electron microscopy, and nitrogen adsorption-desorption analysis. The system, whose colorimetric response was based on the chromogen-free TiO2-based detection of hydrogen peroxide (H2O2), used β-galactosidase and/or glucose oxidase as the biorecognition elements. The selectivity and sensitivity of the biosensors for lactose and glucose was investigated by diffuse reflectance spectroscopy using standard aqueous lactose and glucose solutions and whole milk samples. The results showed that the proposed biosensors had high optical signal reproducibility (RSD = 5–6%), high sensitivity (LOD = 0.005 wt%), and high selectivity. The linear dynamic ranges of lactose and glucose detection were from 0.005 wt% to 0.100 wt%, and the optimal response time of the biosensor was 25 min. The listed features and advantages of label-free detection make the biosensor attractive for simple, inexpensive, sensitive, and selective determination of lactose in milk.

The Potency of Citrus aurantiifolia Swingle and Sea Salt Solution as a Cleansing Agent for Edible Bird’s Nests

The present study aimed to evaluate the potency of Citrus aurantiifolia Swingle and sea salt solution as a promising cleansing agent for edible bird’s nests (EBNs). Ascorbic acid, sodium, and chloride analyses of the C. aurantiifolia Swingle and sea salt solution were conducted using HPLC, ICP-OES, and titrimetry, respectively. The characteristics of physical samples and hydrogen peroxide detection were examined in this study. The reduction activity of the Citrus aurantiifolia Swingle and sea salt solution on the nitrite of 120 white EBNs was studied. This nitrite reduction activity was compared with the available method (standard), drinking water method, 6% C. aurantiifolia Swingle extraction method, and sea salt water. An organoleptic test was performed by three trained panelists to determine the color of the samples before and after treatments. The results showed that the C. aurantiifolia Swingle and sea salt solution contained 0.27 mg/100 mL of ascorbic acid, 76370.93 mg/L of sodium, and 7555.61 mg/100 mL of chloride. In comparison results, the C. aurantiifolia Swingle and sea salt solution can reduce nitrite levels up to 86%, remove hydrogen peroxide, and improve the natural color of EBNs. The present study provides the first potential future cleansing agent for EBNs.

Copper-based nanomaterials as peroxidase candidates for intelligent colorimetric detection and antibacterial applications

With natural polyphenol compound tannic acid (TA) as the ingredient, copper tannate (CuTA) nanolayer material was formed by self-assembly under the conditions of heating and copper ion. Copper ion and tannic acid could coordinate to form Cu–O–C structure which was similar to the Fe–N–C structure of natural heme enzymes. In addition, the obtained CuTA nanomaterial possessed excellent peroxidase-like catalytic activity and stability. Based on this excellent enzymatic activity, CuTA nanomaterials could be used for colorimetric detection of hydrogen peroxide with a smartphone and decomposition of organic dyes. Based on the structural characteristics and catalytic activity, the copper tannate nanozymes could also serve as potential antibacterial reagents to effectively inhibit the growth of gram-negative and positive bacteria in a low hydrogen peroxide level. This work may promote the exploration of novel peroxidase mimetics and broaden the applications of nanozymes.

A Cascade Enzyme System Integrating Peroxidase Mimic with Catalase for Linear Range Expansion of H2 O2 Assay: A Mechanism and Application Study.

Peroxidase (POD) Nanozyme-based hydrogen peroxide (H2 O2 ) detection is popular, but hardly adapt to high concentration of H2 O2 owing to narrow linear range (LR) and low LR maximum. Here, a solution of combining POD and catalase (CAT) is raised to expand the LR of H2 O2 assay via decomposing part of H2 O2 . As a proof of concept, a cascade enzyme system (rGRC) is constructed by integrating ruthenium nanoparticles (RuNPs), CAT and graphene together. The rGRC-based sensor does perform an expanded LR and higher LR maximum for H2 O2 detection. Meanwhile, it is confirmed that LR expansion is closely associated with apparent Km of rGRC, which is determined by the relative enzyme activity between CAT and POD both in theory and in experiment. At last, rGRC is successfully used to detect high concentration of H2 O2 (up to 10mm) in contact lens care solution, which performs higher assay accuracy (close to 100% recovery at 10mm of H2 O2 ) than traditional POD nanozymes. This study brings up a kind of POD/CAT cascade enzyme system and provides a new concept for accurate and facile H2 O2 detection. Additionally, it replenishes a new enzyme-substrate model of achieving the same pattern with competitive inhibition in enzyme reactions.

Enhanced cathodic electrogenerated chemiluminescence of luminol at a MXene–Nafion composite-modified electrode in neutral aqueous solution

Electrogenerated chemiluminescence (ECL) of luminol was studied on a two-dimensional titanium carbide (MXene)–Nafion composite-modified glassy carbon (GC) electrode in a neutral aqueous solution (pH 7). In the present work, Ti3C2Tx MXene was dispersed in a cation-exchange ionomer (Nation) and the resulting MXene–Nafion composite solution was drop-cast on the surface of GC electrode. Due to the strong electrocatalytic activity of the MXene towards the reduction reactions of oxygen and hydrogen peroxide, strong cathodic ECL emissions of luminol related to those reactions were obtained in a neutral aqueous solution. Based on the significant enhancement effect of hydrogen peroxide on the cathodic ECL, the present ECL sensor can detect hydrogen peroxide in the concentration range of 1.0 × 10−8 M ∼ 1.0 × 10−3 M with a detection limit of 3.1 × 10−9 M (S/N = 3). Furthermore, the present ECL sensor exhibits good selectivity towards hydrogen peroxide against interfering species such as glucose, ascorbic acid and uric acid. Therefore, the present ECL sensor could offer a good opportunity to be employed as an alternative transducer for the oxidase-based biosensors in biological fluids.

Ru doping induced lattice distortion of Cu nanoparticles for boosting electrochemical nonenzymatic hydrogen peroxide sensing

In this paper, we report a new strategy to activate the electrocatalytic activity of Cu to realize the non-enzymatic detection of hydrogen peroxide. The Ru-doped copper nanoparticles were prepared on the surface of carbon materials by direct pyrolysis of Ru in exchange for Cu-BTC metal-organic framework. The materials were characterized by transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD). Surprisingly, Ru doping induced obvious lattice distortion of Cu nanoparticles, which made Cu nanoparticles exhibit excellent electrocatalytic activity for hydrogen peroxide reduction. The sensor based on Ru-doped Cu nanoparticles can detect hydrogen peroxide in a wide linear range from 0.01 mM to 5.55 mM. Moreover, as a hydrogen peroxide sensor, it has a high sensitivity of 327.14 µA·mM−1·cm−2 and a low detection limit of 8.9 µM. Therefore, Cu nanoparticles with the lattice distortion was demonstrated to be a potential material for hydrogen peroxide electrochemical sensor.

Prussian Blue and Its Analogues: Electrochemistry and Analytical Applications

This article reviews fundamental aspects of deposition, structure and electrochemistry of Prussian Blue and its analogues. Special attention is given to the metal hexacyanoferrates with potential analytical applications. Prussian Blue and its analogues as advanced sensing materials for nonelectroactive ions are discussed. In contrast to common ‘smart materials', the sensitivity and selectivity of metal hexacyanoferrates to such ions is provided by thermodynamic background. Prussian Blue itself is recognized as the most advantageous low-potential transducer for hydrogen peroxide over all known systems. Both high sensitivity (ca. 1 A M-1 cm-2) and selectivity in relation to oxygen reduction are more than three orders of magnitude higher, than for platinum electrodes. Biosensors based on different transducing principles containing enzymes oxidases are compared, and the devices operated due to hydrogen peroxide detection with the Prussian Blue based transducer are shown to be the most advantageous ones. The future prospects of chemical and biological sensors based on metal hexacyanoferrates are outlined.

PEDOT Films Doped with Titanyl Oxalate as Chemiresistive and Colorimetric Dual-Mode Sensors for the Detection of Hydrogen Peroxide Vapor.

Hydrogen peroxide (H2O2) is commonly used as an oxidizing, bleaching, or antiseptic agent. It is also hazardous at increased concentrations. It is therefore crucial to monitor the presence and concentration of H2O2, particularly in the vapor phase. However, it remains a challenge for many state-of-the-art chemical sensors (e.g., metal oxides) to detect hydrogen peroxide vapor (HPV) because of the interference of moisture in the form of humidity. Moisture, in the form of humidity, is guaranteed to be present in HPV to some extent. To meet this challenge, herein, we report a novel composite material based on poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) doped with ammonium titanyl oxalate (ATO). This material can be fabricated as a thin film on electrode substrates for use in chemiresistive sensing of HPV. The adsorbed H2O2 will react with ATO, causing a colorimetric response in the material body. Combining colorimetric and chemiresistive responses resulted in a more reliable dual-function sensing method that improved the selectivity and sensitivity. Moreover, the composite film of PEDOT:PSS-ATO could be coated with a layer of pure PEDOT via in situ electrochemical synthesis. The pure PEDOT layer was hydrophobic, shielding the sensor material underneath from coming into contact with moisture. This was shown to mitigate the interference of humidity when detecting H2O2. A combination of these material properties makes the double-layer composite film, namely PEDOT:PSS-ATO/PEDOT, an ideal sensor platform for the detection of HPV. For example, upon a 9 min exposure to HPV at a concentration of 1.9 ppm, the electrical resistance of the film increased threefold, surpassing the bounds of the safety threshold. Meanwhile, the colorimetric response observed was 2.55 (defined as the color change ratio), a ratio at which the color change could be easily seen by the naked eye and quantified. We expect that this reported dual-mode sensor will find extensive practical applications in the fields of health and security with real-time, onsite monitoring of HPV.

Stable hemoglobin-based biosensor based on coordination-assisted microfluidic technology for hydrogen peroxide determination

Enhancing the stability and sensitivity of electrochemical biosensors is highly significant for their practical application. Herein, inspired by the formation of mussel foot protein, we proposed a strategy to construct a hemoglobin-based biosensor for hydrogen peroxide detection using a hydrophobic ionic liquid (HIL) coordination assisted microfluidic technology. The active layer HIL@Hb was achieved by mixing BBimPF6 (HIL) and Hb via a microfluidic channel, in which HIL helps to maintain the conformational dynamic mobility of hemoglobin (Hb), while the coordination process in a microfluidic reactor prevents aggregation of Hb. Further, the electrode surface was modified with ultra-thin MXene-Ti3C2 nanosheets to ensure the effective adhesion of active layer and collection of sensing signals, thus improving the sensitivity of the sensor by synergistic catalysis. Experimental results demonstrate that our designed sensor has good repeatability and stability, which can retain 93% of the initial current response after 30 uses and about 90.11% of its primary current response to H2O2 after 30 days. And it has a good linear response range of 1.996–27.232 μM, detection limit reaching 1.996 nM (signal-to-noise ratio, S/N = 3), sensitivity of 52.08 μA·μM−1·cm−2. Overall, this research offers a facile and effective strategy for constructing a stable biosensor to effectively detect hydrogen peroxide.

Preparation of a Red-Emitting, Chitosan-Stabilized Copper Nanocluster Composite and Its Application as a Hydrogen Peroxide Detection Probe in the Analysis of Water Samples.

Hydrogen peroxide (H2O2) is an important reactive oxygen species that mediates a variety of physiological functions in biological processes, and it is an essential mediator in food, pharmaceutical, and environmental analysis. However, H2O2 can be dangerous and toxic at certain concentrations. It is crucial to detect the concentration of H2O2 in the environment for human health and environmental protection. Herein, we prepared the red-emitting copper nanoclusters (Cu NCs) by a one-step method, with lipoic acid (LA) and sodium borohydride as protective ligands and reducing agents, respectively, moreover, adding chitosan (CS) to wrap LA-Cu NCs. The as-prepared LA-Cu NCs@CS have stronger fluorescence than LA-Cu NCs. We found that the presence of H2O2 causes the fluorescence of LA-Cu NCs@CS to be strongly quenched. Based on this, a fluorescent probe based on LA-Cu NCs@CS was constructed for the detection of H2O2 with a limit of detection of 47 nM. The results from this research not only illustrate that the as--developed fluorescent probe exhibits good selectivity and high sensitivity to H2O2 in environmental water samples but also propose a novel strategy to prepare red-emitting copper nanoclusters (Cu NCs) by a one-step method.

Synthesis and molecular structure of V-shaped liquid crystalline compounds: Spectroscopic, mesomorphic, DFT investigations, electrochemical and fluorescence studies

A series of V-shaped compounds consisting of a central phenyl core connected by two identical mesogenic units which possess the imine (C=N) and ester (COO) bonds along with the terminal alkoxy chain (-OCnH2n+1) where n = 6-12. The ultimate compounds were synthesised and characterized by CHN elemental analysis, Fourier-Transform Infrared (FT-IR), nuclear magnetic resonance (1H-NMR), and UV-Visible (UV-Vis) spectroscopic techniques. The mesomorphic properties, thermal behaviour and conformation of compounds were studied by using polarised optical microscopy (POM), and differential scanning calorimetry (DSC). It can be generalized from present study that the V-shaped compounds with odd n carbon number in alkoxy chains were non-mesogenic. Whilst the compounds with shorter alkoxy chains of n = 6 and 8 were monotropic nematic, the compounds which possess longer alkoxy chains (n = 10 and 12) exhibited enantiotropic nematic phase. The computational method Chem3D Pro suggests the molecular structures of all the compounds with even n carbon number in the alkoxy chain. The Gaussian calculation with B3LYP/6-31G+(d,p) condition was employed to further demonstrate the chemical reactivity for all target compounds based on HOMO-LUMO analysis, the energy difference between HOMO-LUMO and surface charges. The target molecules of which the member containing the even n parity along the mesogenic arms have shown the same trend of electrocatalytic behaviour particularly toward the detection of hydrogen peroxide via the cyclic voltammetry study. Furthermore, the member with n=12 has been validated as a remarkable fluorogenic probe for the detection of Zn2+ ion.

A simple preparation of N-doped reduced graphene oxide as an electrode material for the detection of hydrogen peroxide and glucose

This paper presents a method of simple and facile preparation of N-doped reduced graphene oxide (N-rGO), which can be applied as a metal-free electroactive electrode material for the detection of hydrogen peroxide and glucose. Two different N-rGO samples (N-rGO_850 and N-rGO_950) were obtained by gaseous NH3-assisted thermal modification of reduced graphene oxide (rGO) at temperatures of 850 °C and 950 °C for 4 and 8 h, respectively. The structural properties of the samples obtained were characterized by Raman spectroscopy, XPS, and N2 adsorption-desorption techniques. Taken together, these analyses demonstrate that, compared to the N-rGO_850 sample, N-rGO_950 possesses a considerably higher amount of quaternary nitrogen species, higher surface area, and a greater amount of structural imperfections, which contribute to its excellent electrochemical activity in the detection of H2O2 and glucose. The sensor based on N-rGO_950 displays a fast response time (∼ 6 s) to sensitive detection of H2O2, a wide linear range (0.1 – 10.7 mM), a sufficiently low limit of detection (LOD) of 26.0 μM, and a superior sensitivity (305 μA mM−1 cm−2). When the same sensor platform used in glucose detection after GOx immobilization results in LOD of 24.7 μM with a linear range of 0.01 – 3.38 mM and a sensitivity of 60.2 μA mM−1 cm−2. Moreover, the proposed (bio)sensor demonstrates satisfactory selectivity, reproducibility, repeatability, and stability.