Carbon-Doping Mesoporous β-Mo₂C Aggregates for Nanomolar Electrochemical Detection of Hydrogen Peroxide

Abstract

The development of a nonenzymatic electrochemical sensor with nanomolar detection of H2O2 has been highly desirable due to its wide applications in bioanalysis. In this paper, the glassy carbon electrode (GCE) modified by carbon-doping molybdenum carbide (β-Mo2C/C/GCE) was simply fabricated by simple drop-coating method and used to detect H2O2 in pretreated human serum. The β-Mo2C/C hierarchical structure is obtained by a one-step pyrolysis of the single-crystal [(H2L)2­(Mo8O26)] n [L = N,N′-bis­(3-pyridin)-1,4-xylyenediamine] and constructed from amounts of nanoparticles (∼10 nm) with a mesoporous size distribution of 42.46 nm. At room temperature, the β-Mo2C/C/GCE sensor has a high sensitivity of 247.73 μA mM–1 cm–2, a low detection limit of 90 nM (signal/noise = 3), as well as a wide linear range of 0.27 μM–2.39 mM, and it shows better electrocatalytic performance of H2O2 than the molybdenum oxide (obtained from the same precursor) modified glassy carbon electrode (α-MoO3/GCE). Such outstanding electrocatalytic performances are related to the synergistic effect of the inherent characteristics of the β-Mo2C/C material. The satisfactory test results of the human serum samples indicate that the β-Mo2C/C/GCE sensor can be used as a good candidate for real-time detection of H2O2 in biological, food, and environmental fields.

Nanocarbon Framework-Supported Ultrafine Mo2C@MoOx Nanoclusters for Photothermal-Enhanced Tumor-Specific Tandem Catalysis Therapy

“…Peaks at 228.6 and 231.7 eV were readily assigned to Mo 2+ in Mo 2 C (3d 5/2 and 3d 3/2 , respectively). − Peaks at 232.1 and 235.1 were assigned to a Mo 5+ species (3d 5/2 and 3d 3/2 , respectively), while the peaks at 232.7 and 235.7 eV are typical for Mo 6+ in MoO 3 (3d 5/2 and 3d 3/2 , respectively). ,− On the basis of the area ratios of the Mo 3d 5/2 for the Mo 5+ and Mo 6+ species in Figure F, the fraction of Mo 5+ species in MoO x shell on the Mo 2 C@MoO x nanoclusters was calculated to be ∼60%. The O 1s XPS spectra for C/Mo 2 C@MoO x (Figure G) were deconvoluted into 4 peaks: O–Mo 6+ (530.6 eV) and O–Mo 5+ (531.3 eV) in MoO x , adsorbed hydroxyl O–H or C=O (532.1 eV), and adsorbed water or carbonate (533.4 eV). , The C 1s spectra for C/Mo 2 C@MoO x were well-fitted by five peaks at 283.8, 284.7, 285.6, 286.5, and 288.4 eV, which could readily be assigned to C–Mo (as Mo 2 C), C–C, C–N, C–O, and O–C=O species (Figure H), respectively. ,− Except for the C–Mo peak, all of the other peaks are associated with the N-doped carbon support or adventitious hydrocarbons. The XPS results strongly support the formation of carbon-supported Mo 2 C@MoO x nanoclusters (consistent with the HRTEM results), with Mo 5+ the dominant Mo species in the oxide shell of the core–shell structured nanoclusters.…”

Cu/Ag Complex Modified Keggin-Type Coordination Polymers for Improved Electrochemical Capacitance, Dual-Function Electrocatalysis, and Sensing Performance

“…Hydrogen peroxide (H 2 O 2 ) is an environmentally friendly chemical reagent, which is widely used in biomedical and industrial production. 63 Ascorbic acid (AA) is a reducing agent that can be used in organisms to scavenge free radicals and prevent cancer. 64 It is significant to detect H 2 O 2 and AA by electrochemical means.…”

Anthraquinone Functionalized Ionic Liquid Based Disposable Electrochemical Sensor for the Enzyme-Free Detection of Hydrogen Peroxide

“…The solid product was separated by filtration and was washed twice with toluene and diethyl ether, then dried to acquire AQ-Cl-IL (Yield 92%). 1 Synthesis of 1-benzyl-3-((9,10-dioxo-9,10-dihydroanthracen-2yl) methyl)-1H-imidazol-3-ium hexafluorophosphate (AQ-PF 6 -IL).-The water-soluble redox IL comprising chloride as the counter anion (AQ-Cl-IL) was converted to water insoluble IL by anion exchange of chloride with hexafluorophosphate as follows: Potassium hexafluorophosphate (0.184 g, 1 mmol) in methanol was dropwise added to the stirring solution of AQ-Cl-IL in methanol (0.414 g, 1 mmol), and continued stirring for 12 h at RT. After completion, the reaction mixture was filtered and washed twice with diethyl ether to obtain AQ-PF 6 -IL as pale-yellow solid (Yield 96%).…”

“…After completion, the reaction mixture was filtered and washed twice with diethyl ether to obtain AQ-PF 6 -IL as pale-yellow solid (Yield 96%). 1 H NMR δ: 5.45 (s, 2H), 5.67 (s, 2H), 7.40-7.47 (t, 5H), 7.86-7.97 (m, 5H), 8.22-8.28 (q, 4H), 9.46 (s, 1H) ppm. 13 Fabrication of AQ-PF 6 -IL/SPE.-Before electrode modification, the SPE was thoroughly washed with water and then activated electrochemically by anodizing at +2.0 V for 500 s in 0.1 M H 2 SO 4 under constant stirring.…”

“…Hydrogen peroxide (H 2 O 2 ) is a vital metabolite in the physiological system which regulates cellular signals, renal functioning, stem cell proliferation, protein synthesis and also kills the invaded pathogens. 1,2 Owing to the strong oxidizing/reducing properties, as well as ease of availability, storability and facile handling, H 2 O 2 has become an indispensable candidate in various domains like clinical (antiseptic/disinfectant), industrial (bleaching), food (processing, packaging and cleaning) and environmental (waste management and water treatment) fields. [3][4][5][6] Besides, H 2 O 2 is the primary reactive oxygen species (ROS) that is produced naturally in mitochondrial organelles by most of the oxidases for effective cell functioning.…”