Sensitive Detection Of Hydrogen Peroxide Research Articles

Molecular fluorinated cobalt phthalocyanine immobilized on ordered mesoporous carbon as an electrochemical sensing platform for sensitive detection of hydrogen peroxide and hydrazine in alkaline medium

• Molecular CoPcF16 is anchored on CMK-3. • The interaction between CoPcF16 and CMK-3 is investigated. • CMK-3-CoPcF16 exhibits high electrocatalytic activity. • Sensitive detection of H 2 O 2 and hydrazine is achieved. Non-precious molecular cobalt phthalocyanine (CoPc) complexes have been considered to be promising electrocatalysts due to diversity of substituents and carbon supporting matrixes. Here, we report a highly dispersed fluorinated CoPc (CoPcF16) molecule electrocatalyst immobilized in ordered mesoporous carbon CMK-3 (CMK-3-CoPcF16) via π-π interaction. The molecular electrocatalyst is characterized by X-ray photoelectron spectroscopy, Raman spectrum, electronic paramagnetic resonance, scanning electron microscopy, transmission electron microscopy and electrochemical impedance spectroscopy. The combination of fluorine substituents and high loading capability of CMK-3 increase the solubility of CoPc, suppress aggregation, and thereby enhance the electrocatalytic performance. As a result, the CMK-3-CoPcF16 modified electrode shows high electrocatalytic activity towards the oxidation of hydrogen peroxide and hydrazine. CMK-3-CoPcF16 hybrid is successfully presented as an electrochemical sensing platform for sensitive detection of H 2 O 2 and hydrazine with a detection limit of 0.03 and 0.2 µM, respectively.

Tailoring atomically dispersed cobalt–nitrogen active sites in wrinkled carbon nanosheets via “fence” isolation for highly sensitive detection of hydrogen peroxide

Wrinkled CNSs with abundant mesopores, high N-doping, and atomically dispersed Co–Nx active sites through “fence” isolation enable efficient H2O2 detection.

Spinel CoMn2O4 hollow nanospheres for very wide linear and sensitive detection of hydrogen peroxide

Spinel CoMn2O4 hollow nanospheres with diameter of ~200 nm were facilely prepared using polyvinylpyrrolidone (PVP) as structure directing agent, which possessed hierarchical pore distribution and large surface area of 43.5 m2 g−1. The above nanomaterials were simply drop-coated on the surface of bare glass carbon electrode (GCE) to generate CoMn2O4/GCE. In phosphate buffer (PBS, pH = 7), the modified electrode presents rapidly sensitive response and low detection limit (0.38 μM) to H2O2. Especially, its linear detection range (0.0012–100.4 mM) is the widest among reported spinel oxide-based electrochemical sensors to date. This excellent electrocatalytic H2O2 sensing performance primarily derives from the synergism of unique hollow nanosphere structure and the redox coupling of Co3+/Co2+ and Mn3+/Mn2+. In addition, the CoMn2O4/GCE sensor also shows good H2O2 recovery in rat serum and commercial disinfectant, indicating that it has a certain potential application in related environmental and biological fields.

High-activity daisy-like zeolitic imidazolate framework-67/reduced grapheme oxide-based colorimetric biosensor for sensitive detection of hydrogen peroxide

Colorimetric biosensors, based on enzyme-like nanomaterials, have come into the spotlight in virtue of their visual detection. Herein, a daisy-like zeolitic imidazolate framework-67/reduced grapheme oxide (ZIF-67/rGO) nanozyme with unique 3D hierarchical structures has been designed to realize visual detection of hydrogen peroxide (H2O2) that is recognized as a strong oxidizing agent or reactive oxygen species associated with oxidative stress in biological systems. The daisy-like ZIF-67/rGO is prepared by a facile one-step liquid-phase method conducted under room temperature. The successful introduction of rGO endows the daisy-like ZIF-67/rGO nanozyme with abundant porous structure, high specific surface area, and good charge transfer capability, which significantly accelerates the adsorbability and recognition towards the substrates and the oxidation rate of TMB-H2O2 reaction, and thus improving the nanozyme activity observably. It is conductive to nanozyme-modulated H2O2 determination. The established colorimetric biosensor platform based on ZIF-67/rGO nanozyme exhibits remarkable sensitivity and high specificity for the application in visual detection of H2O2. The detection limit of ZIF-67/rGO-based biosensor platform is as low as 3.81 μM, which is nearly 8 times lower than that of ZIF-67-based biosensor platform. Moreover, its potential applicability as an ideal platform for colorimetric biosensors is demonstrated by testing the concentration of H2O2 in milk samples, which sheds light on the promising application of the proposed biosensing system in point-of-care detection.

Zr(IV)-based metal-organic framework nanocomposites with enhanced peroxidase-like activity as a colorimetric sensing platform for sensitive detection of hydrogen peroxide and phenol

Recently, metal-organic frameworks (MOFs) have great potential as an emerging peroxide-mimicking enzyme, and the improvement of its enzyme-like activity is desired. There are few studies on improving the peroxidase-like activity of MOFs by using the strategy of size reduction. Moreover, it is challenging to enhance the activity of Zr-based MOFs with peroxidase-mimicking activity by size reduction strategy. In this work, the synthesis of Zr-based MOFs capped with polyvinylpyrrolidone (Zr-MOF-PVP) was firstly reported to reduce crystal size of peroxidase-mimicking enzyme for enhanced catalytic activity. Using the 3,3′,5,5′-Tetramethylbenzidine (TMB) as substrate, the synthesized Zr-MOF-PVP nanocomposites with nanosize (about 45 nm) possessed obviously enhanced peroxidase-like activity compared with the pristine Zr-MOF. Based on the above, the Zr-MOF-PVP was also successfully applied in constructing colorimetric detection. By using hydrogen peroxide (H2O2) and phenol as the model analytes, the satisfactory detection performance was obtained, indicating that the proposed method had an attractive application prospect in the field of peroxidase-related detection. Besides, this work also provided a new perspective for improving the catalytic activity of nanozymes.

One-Step Preparation of Nitrogen-Doped Graphene Quantum Dots With Anodic Electrochemiluminescence for Sensitive Detection of Hydrogen Peroxide and Glucose.

Simple and efficient synthesis of graphene quantum dots (GQDs) with anodic electrochemiluminescence (ECL) remains a great challenge. Herein, we present an anodic ECL-sensing platform based on nitrogen-doped GQDs (N-GQDs), which enables sensitive detection of hydrogen peroxide (H2O2) and glucose. N-GQDs are easily prepared using one-step molecular fusion between carbon precursor and a dopant in an alkaline hydrothermal process. The synthesis is simple, green, and has high production yield. The as-prepared N-GQDs exhibit a single graphene-layered structure, uniform size, and good crystalline. In the presence of H2O2, N-GQDs possess high anodic ECL activity owing to the functional hydrazide groups. With N-GQDs being ECL probes, sensitive detection of H2O2 in the range of 0.3–100.0 μM with a limit of detection or LOD of 63 nM is achieved. As the oxidation of glucose catalyzed by glucose oxidase (GOx) produces H2O2, sensitive detection of glucose is also realized in the range of 0.7–90.0 μM (LOD of 96 nM).

Fabrication of label-free and eco-friendly ROS optical sensor with potent antioxidant properties for sensitive hydrogen peroxide detection in human plasma

Herein, biogenic silver nanoparticles, Cafi-AgNPs was produced based on Cassia fistula-phenolic-rich extract (Cafi) only, without any toxic chemical reagent or organic solvent. Cafi bioactives were characterized using UHPLC-ESI-QTOF-MS/MS analysis. The as-synthesized nanoparticles were characterized using physico-chemical techniques including UV–vis, TEM, SEM, EDX, FTIR, DLS, Zeta potential, XRD, TGA and DGA. In addition, their antioxidant properties and cytocompatibility on erythrocytes and HEK-293 cells were examined. Results show that Cafi mediated the successful synthesis of stable well-dispersed AgNPs. Cafi-AgNPs demonstrated potent reducing and radical scavenging activities against ABTS˙+, DPPH˙ and NO˙. Furthermore, Cafi-AgNPs was compatible with human erythrocytes and HEK-293 cells. Based on the superior surface plasmonic and biological attributes of Cafi-AgNPs, its potential in H2O2 sensing was evaluated. The proposed sensor demonstrated satisfactory analytical performances with linearity of 10–200 μM, detection limit of 3.0 μM for H2O2, and was successfully applied in the detection of H2O2 in human plasma.

Colorimetric assay based on horseradish peroxidase/reduced graphene oxide hybrid for sensitive detection of hydrogen peroxide in beverages

We reported a simple and sensitive colorimetric assay for detection of hydrogen peroxide (H2O2) based on the oxidation of 2,2׳-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) by UV–Vis spectroscopy method. The reduced graphene oxide (rGO) was prepared using green tea extract as bio-reducing and stabilizer agent and decorated by horseradish peroxidase (HRP). The surface of Au interface was modified with HRP-rGO hybrid. The formation of HRP-rGO hybrid was confirmed by cyclic voltammetry, scanning electron microscopy (SEM), energy-dispersive X-ray Spectroscopy (EDX) and Raman spectroscopy·H2O2 can be catalysed by HRP-rGO hybrid and converted into water and oxygen. The ABTS substrate takes up oxygen to form a green coloured product that has absorption peaks at 421, 655 nm and 737 nm. The colour development is linearly dependent on HRP in the range of 4–50 µg/L. The color of the green product solution is stable for 20 min. The absorption intensity is strongly related to the hydrogen peroxide concentration. The absorption intensity of the formed product scaled linearly with the hydrogen peroxide concentration in the ranges of 0.3–20 µM and 20–8000 µM with a detection limit of ≈15 nM could be achieved. The biosensor with excellent limit detection and wide linear ranges was adapted to monitor H2O2 in different beverages.

Luminescent NaTb(SO4)2 nanoprobe for hydrogen peroxide based on switchable fluorescence of Tb(IV)/Tb(III) redox couple

The accurate and sensitive detection of hydrogen peroxide (H2O2) is of practical significance in the fields of bioanalysis, medicine, environmental protection as well as food industry. Herein, we design and fabricate NaTb(SO4)2 nanoparticles (NPs) as novel fluorescent nanoprobes for H2O2 detection. The design strategy is based on the fluorescence quenching occurred during the oxidation of Tb(III) to Tb(IV) upon H2O2 addition. The sensing of NaTb(SO4)2 NPs to H2O2 is in a “turn-off” mode, and the sensitivity is tunable by the pH due to the pH-dependence of the oxidizing ability of H2O2. Superior to most of the reported H2O2 sensors, NaTb(SO4)2 NPs exhibit reliable stability in acidic environment and a more sensitive response to H2O2 with a limit of detection (LOD) down to 0.047 μM at pH = 3.2. Based on its high sensitivity and reliable stability, the NaTb(SO4)2 NPs is anticipated to find potential applications in the field of biosensors.

A Highly Efficient Nonenzymatic Hydrogen Peroxide Electrochemical Sensor Using Mesoporous Carbon Doped ZnO Nanocomposite

Carbon nanomaterial coupled with inorganic semiconductor based metal oxide is a facile route to develop effective electrochemical sensors. Herein, an electrochemical investigation was carried out for selective and sensitive detection of hydrogen peroxide (H2O2) using 5% mesoporous carbon doped ZnO (Meso-C/ZnO) nanocomposite modified glassy carbon electrode (GCE). The ZnO nanomaterial was synthesized by a F127 structural template agent in a modified sol-gel procedure. Then, a simple ultra-sonication technique was employed to synthesize Meso-C/ZnO nanocomposite. XRD, TEM, FTIR, Raman, and XPS techniques were successfully applied to characterize the as-fabricated nanocomposite. CV and EIS measurements were used to evaluate the electrocatalytic activity of the modified electrode compared to pure ZnO modified GCE and unmodified GCE. The sensing efficiency of the active modified electrode was examined with square wave voltammetry (SWV) technique and the sensor exhibits excellent performance towards the detection of H2O2 in a wide linear concentration range (from 50 μM to 981 μM), with high sensitivity (0.04648 μMμA−1 cm−2), and low limit of detection (6.25 μM). Additionally, the selectivity test using several common interfering species demonstrated excellent anti-interfering ability. Furthermore, the fabricated electrode showed excellent reproducibility and operational stability as well as suitability for the real sample analysis. Thus, this new sensor is considered as very auspicious candidate in several fields of science and industry.

Intrinsic catalase-mimicking MOFzyme for sensitive detection of hydrogen peroxide and ferric ions

Lanthanide metal-organic frameworks (Ln-MOFs) exhibit outstanding properties, including high chemical and thermal stability, as well as their promising enzyme-mimic activity (MOFzyme). A new cerium MOFs (Ce-MOF) was synthesized via a solvothermal method using organic linker 4,4′,4″-nitrilotribenzoic acid (H3NTB). The crystallinity of the prepared material was confirmed using X-ray diffraction (XRD). The coordination between Ce and H3NTB was approved using Fourier transforms infrared (FT-IR). The chemical and oxidation state of Ce-MOF was characterized using X-ray photoelectron spectroscopy (XPS). The analysis of XPS data suggested the presence of two oxidation states of cerium, i.e., Ce(III) and Ce(IV). According to the imaging using a scanning electron microscope (SEM) and transmission electron microscope (TEM), Ce-MOF exhibits hexagonal rods’ morphology. Ce-MOF offered thermal stability up to 350 °C. It showed a fluorescence emission signal at wavelength 550 nm with a Stock’s shift of 200 nm. Ce-MOF’s application as a probe for sensing hydrogen peroxide (H2O2) and ferric ions (Fe3+) was reported. Ce-MOF exhibited peroxidase MOFzyme activity. Thus, it offered a turn-on emission upon interaction with different concentrations of H2O2. It detects Fe3+ ions with a limit of detection (LOD) and a linear range of 0.016 µM and 0.016–0.133 µM, respectively. The study also investigated the mechanisms of sensing for H2O2 and Fe3+ ions. The changes in the emission signals were due to the intrinsic catalase activity of Ce-MOF. Ce-MOF offered MOFzyme properties providing a promising feature for biocatalysis and biosensing applications.

Electrochemical sensor based on the Mn3O4/CeO2 nanocomposite with abundant oxygen vacancies for highly sensitive detection of hydrogen peroxide released from living cells.

Based on the strategy of increasing the number of oxygen vacancies to improve the catalytic performance, we have developed a novel electrochemical sensor based on the multivalent metal oxides cerium dioxide and manganous oxide (Mn3O4/CeO2) for reliable determination of extracellular hydrogen peroxide (H2O2) released from living cells. The Mn3O4/CeO2 nanocomposite was characterized by high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The electrochemical performance of the Mn3O4/CeO2 nanocomposite modified glassy carbon electrode (Mn3O4/CeO2/GCE) was investigated. Owing to the abundant oxygen vacancies and strong synergistic effect between the multivalent Ce and Mn, the sensor exhibited excellent catalytic activity and selectivity for the electrochemical detection of H2O2 with a low quantitation limit of 2 nM. Moreover, Mn3O4/CeO2/GCE exhibited excellent reproducibility, repeatability, and long-term storage stability. Because of these remarkable analytical advantages, the constructed sensor was able to determine H2O2 released from living cells with satisfactory results. The results showed that the Mn3O4/CeO2 sensor is a promising candidate for a nanoenzymatic H2O2 sensor with the possibility of applications in physiology and diagnosis.

Reasonable design of an MXene-based enzyme-free amperometric sensing interface for highly sensitive hydrogen peroxide detection

Sensitive detection of H2O2 in the nano- to micromolar range is critical for health monitoring and disease diagnosis. Two-dimensional transition metal carbides or/and nitrides (called MXenes, MXs) have excellent potential applications in the electrochemical field due to their outstanding electrical conductivity and catalytic properties. In this work, Ti3C2Tx (MX) was employed for the construction of a sensitive and enzyme-free electrochemical sensing interface for the detection of hydrogen peroxide (H2O2) through a simple and effective method. Prussian blue (PB) was electrochemically deposited on the surface of a glassy carbon electrode (GCE). Chitosan (CS) and MX were sequentially dripped onto the PB modified GCE surface. The reasonable fabrication of the MX/CS/PB/GCE sensing interface presented good electrochemical sensing performance towards H2O2 with a low limit of detection (4 nM), a wide linear range from 50 nM to 667 μM and good selectivity. The proposed MX/CS/PB/GCE has been proven to monitor H2O2 in food samples and biological samples with recoveries between 94.7% and 100.3%. This work has made a beneficial attempt and research for exploring and expanding the application of MXs in the field of electrochemical sensing.

Optimization of silver nanoparticles modified pencil graphite electrodes via altering sputtering condition and addition of graphene

Pencil graphite electrodes (PGEs) were modified by diverse assemblies of silver nanoparticles (AgNPs) via the vacuum sputtering approach and used for rapid and sensitive detection of hydrogen peroxide (H2O2). 32 PGEs were modified under different stimulation currents and sputtering times to determine the optimal sputtering condition. The voltammetric behavior of modified electrodes was evaluated toward hydrogen peroxide reduction and the electrode modified at 10 mA and 10 s had the highest peak current (Ip) in 0.1 M phosphate buffer solution (pH 5.8) and in the presence of 1.6 mM H2O2. Analytical techniques, including field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and atomic force microscopy were also utilized for characterizing the modified electrodes. Thereafter, sputtering at the optimum condition was done on a PGE modified by graphene, which led to exhibiting a higher value of Ip compared to the optimal modified PGE. The current response of the sensor was linear between H2O2 concentrations of 0.1 and 8.0 mM and the limit of detection was estimated to be 0.21 μM at a signal-to-noise ratio of 3. In addition, the optimal modified electrode showed high sensitivity upon the addition of adenine, uric acid, and dopamine, proving that these compounds cannot interfere with the detection of H2O2 at a constant potential of −0.65 V vs. Ag/AgCl (pH 5.8).

A facile one-pot synthesis of Au core flower surrounding with thin Co3O4 shell for highly sensitive detection of hydrogen peroxide

In this study, we described the facile synthesis of Au core flower surrounding with thin Co3O4 shell for enhanced electrochemical sensing of H2O2. Such core-shell structure was obtained by employing Au3+ to oxidize Co2+ under alkaline conditions for triggering the redox assembly process. The experiment results revealed that conductive Au core flower was surrounded by thin Co3O4 shell, and such structure not only accelerates electron transfer rate but also provides more effective active sites for H2O2 reaction, therefore making the sensor based on Au@Co3O4 exhibit an excellent performance for H2O2 analysis with a linear range of 0.2 μM-7.1 mM, a high sensitivity of 722.4 μA mM−1 cm-2 and a low detection limit of 0.06 μM. The excellent experimental results implied that Au@Co3O4 nanocomposite was a promising sensing material for electrochemical detection of H2O2.

S-doped reduced graphene oxide: a novel peroxidase mimetic and its application in sensitive detection of hydrogen peroxide and glucose.

This article presents a novel peroxidase mimetic by doping S atoms into reduced graphene oxide (rGO), which was synthesized through a facile hydrothermal reaction without any templates or surfactants. The peroxidase-like activity of S-doped rGO (S-rGO) is greatly boosted compared with the pristine rGO, demonstrating the peroxidase-like active sites are dominantly originated in sulfur-containing groups. The steady-state kinetic studies further indicate that S-rGO obeys the typical Michaelis-Menten curves and has a much smaller Michaelis constant (Km) for hydrogen peroxide (H2O2) and 3, 3', 5, 5'-tetramethylbenzidine (TMB). In view of the outstanding performance of S-rGO as a peroxidase mimetic, an efficient and sensitive colorimetric detection platform for H2O2 and glucose has been successfully established. The linear detection for H2O2 is obtained in a range of 0.1-1μM with an extremely lower detection limit of 0.042μM, and glucose can be measured in a linear range of 1-100μM, giving a detection limit of 0.38μM. This study not only provides a new avenue for the reasonable design of heteroatom-doped carbon-based nanomaterials but also offers meaningful reference for detecting the important biomolecules in biotechnology. Graphical abstract.

Functionalised liquid crystal microfibers for hydrogen peroxide and catalase detection using whispering gallery mode

ABSTRACT In this work, we demonstrate, for the first time, a whispering gallery mode (WGM) lasing-based liquid crystal (LC) soft-matter microfiber biosensor for real-time and sensitive detection of hydrogen peroxide and catalase. The functionalised nematic LC 4-cyano-4ʹ-pentylbiphenyl (5CB) microfibers served as both optical microresonators and sensing actuators. The resonance spectral shift in WGMs can be used as a stable and reliable indicator of analyte concentrations. The detection limits for hydrogen peroxide and catalase were as low as ~0.26 μM and ~1 ng/mL, respectively. Direct measurement of the WGM lasing spectrum of LC soft-matter microfibers can be expected as an alternative method to detect analytes without the need for polarised image analysis in current LC sensor systems. This research provides a preliminary basis for the development of soft-matter microfiber biosensors with high sensitivity for detecting biochemical molecules.

Facile Electrochemical Routes for the Composite Coating on Au Inverse Opals As Highly-Sensitive Enzyme-Free Biosensors

The highly sensitive detection of hydrogen peroxide (H2O2) is of practical importance due to its involvement in the biofunction and signal transduction of cells. Various electrochemical techniques have been explored and studied for its detection, which can be realized through either enzymatic or non-enzymatic sensors. Particularly, non-enzymatic biosensors have been in great demand because of their high stability, high reproducibility, and less susceptible to environmental factors compared to the enzyme-based approach. However, many of them display inferior sensitivity or poor selectivity. Hence, this work aims to develop a highly sensitive non-enzymatic biosensor through structural and compositional approaches. From a structural point of view, Au inverse opals are utilized as the sensor scaffold due to their intriguing porous structure. The spatial arrangement of these materials resembles a honeycomb structure, which provides a high specific surface area, efficient mass transport, and strong mechanical stability. In addition to the benefits brought by inverse opals, we further incorporate a composite coating based on Cu2O to decorate the scaffold surface. Through the combination of a well-ordered pore structure with additional functionalization by composite formation, a synergistic improvement could be realized. To fabricate such structural biosensors, an expedited self-assembly process exploiting electrophoresis technique is first adopted to produce a colloidal crystal template. Subsequent electrodeposition processes are performed to construct the Au inverse opals and relevant functional coatings. The sensing performance of these 3D sensors is then evaluated by the detection of H2O2 using cyclic voltammetric analysis. Their structural and compositional characterizations are conducted by SEM, EDX, XPS, and Raman spectroscopy.

Electrostatic Self‐Assembled Bracelet‐Like Au@Pt Nanoparticles: An Efficient Electrocatalyst for Highly Sensitive Non‐Enzymatic Hydrogen Peroxide Sensing

AbstractIn this study, a non‐enzymatic electrochemical sensor was developed based on bracelet‐like Au@Pt nanoparticles (B−Au@Pt NPs) and used for extremely sensitive detection of hydrogen peroxide (H2O2). The uniquely shaped B−Au@Pt NPs with a well‐defined core–shell structure were synthesized by a combination of seed‐mediated growth and electrostatic self‐assembly, especially using both sodium citrate (SC) and cetyltrimethylammonium chloride (CTAC). Through characterization by dynamic light scattering (DLS), high‐resolution transmission electron microscopy (HRTEM) and UV/Vis absorption spectra, it was evident that each Au NP was surrounded by several ultrasmall Pt NPs, all of which were detached from and lose contact with Au cores. Compared with sea urchin‐like Au@Pt NPs (S−Au@Pt NPs) synthesized only by a seed‐mediated growth, B−Au@Pt NPs presented obvious electrochemical response and exhibited substantially enhanced electrocatalytic activity towards H2O2 reduction. This H2O2 sensor, denoted as B−Au@Pt NPs/GCE (GCE=glassy carbon electrode), with enhanced sensitivity, has shown much better sensing performance than other sensors based on Pt reported earlier, particularly the high sensitivity of 882.2 μA mM−1 cm−2. Moreover, this non‐enzymatic electrochemical sensor based on B−Au@Pt NPs may offer the potential for sensitive detection of H2O2 in aquatic environmental monitoring.

Hierarchical Mo2C@MoS2 nanorods as electrochemical sensors for highly sensitive detection of hydrogen peroxide and cancer cells

Heterostructures hierarchically integrating various building blocks are promising to construct sensitive and versatile biosensing platforms. Herein, hierarchical Mo2C@MoS2 consisting of interlayer-expanded MoS2 nanosheets wrapping on Mo2C nanorods is developed as a sensitive and bifunctional electrochemical platform to detect cellular metabolism products (e.g., H2O2) and cancer cells. Utilizing the merits of one-dimensional Mo2C axis (e.g., high conductivity) and two-dimensional MoS2 nanosheets (e.g., enhanced *OH binding, highly exposed edge-sites, and tolerance against oxidative H2O2), the Mo2C@MoS2 afford a high sensitivity (1080 μA mM−1 cm-2) and a low detection limit (0.2 μM) for H2O2 sensing, superior to the most of materials free from enzymes and noble metals. Its outstanding tolerance to various interferents ensures the practical monitoring of the intracellular H2O2 amount in MDA-MB-231, a human breast cancer cell line, which provides an indirect but available detection of tumor cells. As a versatile sensing platform, moreover the Mo2C@MoS2 with rich surface amino groups performs well to directly and specifically detect MDA-MB-231 after immobilizing folic acid. This work is anticipated to open up new opportunities toward high-performance sensing materials via surface/interfacial engineering on heterostructures.