Catalytic Electron Transfer Research Articles

Immobilization of Membrane-Associated Protein Complexes on SERS-Active Nanomaterials for Structural and Dynamic Characterization.

Exploring the structural basis of membrane proteins is significant for a deeper understanding of protein functions. In situ analysis of membrane proteins and their dynamics, however, still challenges conventional techniques. Here we report the first attempt to immobilize membrane protein complexes on surface-enhanced Raman scattering (SERS)-active supports, titanium dioxide-coated silver (Ag@TiO2) nanoparticles. Biocompatible immobilization of microsomal monooxygenase complexes is achieved through lipid fission and fusion. SERS activity of the Ag@TiO2 nanoparticles enables in situ monitoring of protein-protein electron transfer and enzyme catalysis in real time. Through SERS fingerprints of the monooxygenase redox centers, the correlations between these protein-ligand interactions and reactive oxygen species generation are revealed, providing novel insights into the molecular mechanisms underlying monooxygenase-mediated apoptotic regulation. This study offers a novel strategy to explore structure-function relationships of membrane protein complexes and has the potential to advance the development of novel reactive oxygen species-inducing drugs for cancer therapy.

Ultra-Low Alginate-Based Multifunctional Composite Binders for Enhanced Mechanical, Electrochemical, and Thermal Performance of Li-S Batteries.

The practical application of Li-S batteries, which hold great potential as energy storage devices, is impeded by various challenges, such as capacity degradation caused volume change, polysulfide shuttling, poor electrode kinetics, and safety concerns. Binder plays a crucial role in suppressing volume change of cathode side, thereby enhancing the electrochemical performance of Li-S batteries. In this research, a novel network binder (SA-Co-PEDOT) composed of sodium alginate is presented, Co2+ ions as cross-linking agent and PEDOT as an electronic conductor. The theoretical analysis and experimental testing confirm that the SA-Co-PEDOT binder with synergistic combination of catalytic center and electron transfer network effectively mitigates large volumetric changes during cycling while simultaneously enhancing electrode kinetics through controlling the deposition morphology of sulfur end product and its nucleation and dissolution. As a result, it achieves a capacity of 844 mAh g-1 after 150 cycles at 0.2 C. Moreover, the electrode with SA-Co-PEDOT binder subjected a bending test maintains a capacity of 395 mAh g-1 after 500 cycles at 0.5 C, exhibiting an impressively low decay rate of only 0.11%. Even with an ultra-low content of 2 wt.% SA-Co-PEDOT binder, the electrode still maintains a capacity of 999.7 mAh g-1 after 100 cycles at 0.5 C.

Preparation Of Modified Surfaces Based On Tannic Acid and Carbon Nanotubes and Investigation Of Their Electrochemical Properties

This study focuses on the electrochemical investigation of modifiers and their components that can provide the easiest and most sensitive results for electrochemical sensors. For this purpose, a nanocomposite of tannic acid and carbon nanotubes with extraordinary properties was obtained. The nanocomposite and its components were immobilized on glassy carbon electrode surfaces by the drop-drying technique. The morphological and electrochemical properties of the nanocomposite and its components were examined by scanning electron microscopy and cyclic voltammetry techniques. The surfaces modified with the nanocomposite and its components exhibited different electrochemical behaviors. Tests performed in ferricyanide, ferrocene, ruthenium hexamine (III) chloride, and ferricyanide/ferrocyanide probes showed that the nanocomposite-modified surface exhibited the best voltammetric behavior. Scan rate and pH studies showed that the nanocomposite-modified surface catalyzed electron transfer more and increased the active surface area.

Regulatory roles of extracellular polymeric substances in uranium reduction via extracellular electron transfer by Desulfovibrio vulgaris UR1

The pathway of reducing U(VI) to insoluble U(IV) using electroactive bacteria has become an effective and promising approach to address uranium-contaminated water caused by human activities. However, knowledge regarding the roles of extracellular polymeric substances (EPS) in the uranium reduction process involving in extracellular electron transfer (EET) mechanisms is limited. Here, this study isolated a novel U(VI)-reducing strain, Desulfovibrio vulgaris UR1, with a high uranium removal capacity of 2.75 mM/(g dry cell). Based on a reliable EPS extraction method (45 °C heating), manipulation of EPS in D. vulgaris UR1 suspensions (removal or addition of EPS) highlighted its critical role in facilitating uranium reduction efficiency. On the second day, U(VI) removal rates varied significantly across systems with different EPS contents: 60.8% in the EPS-added system, 48.5% in the pristine system, and 22.2% in the EPS-removed system. Characterization of biogenic solids confirmed the reduction of U(VI) by D. vulgaris UR1, and the main products were uraninite and UO2 (2.88–4.32 nm in diameter). As EPS formed a permeable barrier, these nanoparticles were primarily immobilized within the EPS in EPS-retained/EPS-added cells, and within the periplasm in EPS-removed cells. Multiple electroactive substances, such as tyrosine/tryptophan aromatic compounds, flavins, and quinone-like substances, were identified in EPS, which might be the reason for enhancement of uranium reduction via providing more electron shuttles. Furthermore, proteomics revealed that a large number of proteins in EPS were enriched in the subcategories of catalytic activity and electron transfer activity. Among these, iron-sulfur proteins, such as hydroxylamine reductase (P31101), pyruvate: ferredoxin oxidoreductase (A0A0H3A501), and sulfite reductase (P45574), played the most critical role in regulating EET in D. vulgaris UR1. This work highlighted the importance of EPS in the uranium reduction by D. vulgaris UR1, indicating that EPS functioned as both a reducing agent and a permeation barrier for access to heavy metal uranium.

Synthesis and electrochemical investigation of Cu@FeLn (Eu, Sm, and Gd)-N-C composites for energy conversion and storage applications

The slow reaction rates observed in the Oxygen Reduction Reaction (ORR) pose a significant obstacle in advancing fuel cell technology. Consequently, ORR plays a pivotal role in determining the operational efficiency of fuel cell and energy storage systems. Accordingly, the synthesis of a cathodic electrocatalyst with high efficiency has become an attractive topic for researchers. In this empirical study, three trimetallic electrocatalysts are synthesized and electrochemically appraised. By introducing three lanthanides, namely Gadolinium (Gd), Samarium (Sm), and Europium (Eu), into CuFeZIF-8, new composites successfully are synthesized as Cu@FeLn (Eu, Sm, and Gd)-N-C. These functional materials find application in the context of the ORR and supercapacitor technologies. In order to enhance stability, control surface area, and prevent agglomeration during high-temperature pyrolysis, the silicon cover protection technique is employed. The primary objective in this investigation is to assess the influence of mSiO2 coating on the electrochemical parameters of these electrocatalysts. To characterize the fabricated samples, seven characterization tests are utilized. Electrochemical measurements are conducted employing a three-electrode cell configuration within an alkaline environment. The results illustrated that the Cu@FeGd-N-C sample, with an onset potential of −0.043 V vs. Ag/AgCl, exhibited the best ORR performance. Also, the electron transfer number of Cu@FeSm-N-C was computed as 3.56. The half-wave potentials of Cu@FeSm-N-C, Cu@FeEu-N-C, and Cu@FeGd-N-C were found to be −0.34, −0.23, and −0.18 V vs. Ag/AgCl, respectively. A less negative half-wave potential typically suggests superior performance, signifying a lower overpotential requirement for the ORR process. The specific capacitance for Cu@FeGd-N-C electrode at 1 A/g was determined as 144.4 F g−1. The inclusion of lanthanides, Fe, and Cu into ZIF-8 is observed to notably improve both catalytic activity and electron transfer. Also, the outcomes showed that mesoporous silica-protected pyrolysis could be a useful strategy for improving the efficiency of energy conversion and energy storage equipment.

Visible-Light [4+2] Homodimerization of Decomposition-Prone Styrenes via Electron Transfer Catalysis of Diaryl Diselenides.

The facile electron transfer catalysis of diaryl diselenides was utilized for the visible-light [4+2] homodimerization of decomposition-prone styrenes. The reaction required only 0.5 mol % TPT+BF4- photocatalyst and 1.5 mol % electron transfer catalyst (ArSe)2. The spontaneous electron transfer capability of diaryl diselenides was demonstrated for the first time, leading to the sequestration of redox-prone radical cation intermediates via electron transfer processes. A variety of polymerization-prone styrenes smoothly underwent the visible-light-promoted [4+2] homodimerization to tetralin derivatives.

Self-enhanced nanohydrogel electrochemiluminescence biosensor based on CRISPR/Cas12a and gold platinum nanoparticles modification for high-sensitivity detection of Burkholderia pseudomallei

The simple, rapid, and accurate detection of highly lethal melioidosis is crucial for early clinical diagnosis and improving cure rates. Currently, due to time consumption, low sensitivity and detection rate the existing clinical detection methods cannot satisfy the needs of clinical diagnosis. Herein, a novel self-enhanced porous hydrogel material (Au@PEI-ABEI@Pt) for ultrasensitive ECL strategy of detection B. pseudomallei was report. The novel porous hydrogel material composed of PEI-ABEI porous hydrogel, gold nanoparticles (AuNP) and platinum nanoparticles (PtNP) have large specific surface area and porous structure, which not only fix more ABEI to realize self-enhanced ECL signal amplification, but also facilitate ion diffusion and efficient utilization of catalytic materials, realizing rapid electron transfer and zero-distance catalysis, significantly improving the initial signal of ECL sensor. Moreover, the most attractive aspect is that Au@PEI-ABEI@Pt hydrogels with good biocompatibility can achieve widespread application of CRISPR/Cas12a in solid-phase carriers without affecting the sensitivity, specificity and shearing activity of CRISPR/Cas12a. After coupling with the ECL system and CRISPR/Cas12a signal amplification strategy, the Au@PEI-ABEI@Pt can achieve an ultrasensitive ECL assay of B. pseudomallei with the LOD of 5 CFU mL−1 in complex samples, with high specificity and stability to effectively classify B. pseudomallei and other Gram-negative bacteria. This study shows that the developed porous hydrogel materials not only serve as an excellent ECL signal reporter to significantly improve the detection sensitivity of ECL biosensors, but also provide a new approach for the wide application of CRISPR/Cas systems in solid-phase carriers.

Au nanoparticle‐catalyzed electron transfer from ammonia‐borane to Ru(NH3)63+ for sensitive biosensing

AbstractMetal nanoparticle (NP)‐catalyzed electron transfer (ET) from a reducing agent to a metal complex is useful for signal amplification in biosensors. For efficient ET, the metal complex must undergo rapid outer‐sphere reactions, be highly water‐soluble, and effectively penetrate bio/organic layers on metal NPs. Our study identifies Ru(NH3)63+ as well‐suited for this purpose. Among reducing agents, ammonia‐borane (AB) enables rapid metal NP‐catalyzed ET, with Au, Pt, and Pd NPs displaying similar catalytic activities. The pseudo second‐order rate constant for 20‐nm Au NP‐catalyzed ET from AB to Ru(NH3)63+ (1.4 × 108 M−1 s−1) approaches the diffusion‐controlled rate constant. Despite immunoglobulin G and bovine serum albumin passively adsorbed on Au NPs, catalytic activity remains largely unaffected. Applying Au NP‐catalyzed ET to prostate‐specific antigen detection in human serum achieves a low detection limit of 10 pg/mL. These findings highlight the potential of Ru(NH3)63+ and AB in designing biosensors based on rapid catalytic reaction.

Ce/Fe bimetallic MOF derivatives in situ modified bulk carbon aerogel composite cathode for efficient heterogeneous electro-fenton degradation of chloramphenicol

In this study, we utilized a Ce-modified iron-based metal-organic framework derivative to in situ modify bulk CA (Ce/Fe@C-CA) as a bifunctional composite cathode to degrade chloramphenicol (CAP) in the heterogeneous electro-Fenton (EF) process. The composite cathode exhibited satisfactory CAP degradation efficiency, wide pH adaptability (2–9) and low metal leaching. Under the appropriate conditions (pH = 5, current density = 6 mA/cm2), 94.89% of CAP degradation efficiency was obtained within 60 min. The introduction of Ce increased the oxygen vacancy content, enhanced the cathodic electrochemical activity, promoted the production of a variety of reactive oxygen species and participates in the degradation of CAP, of which ·OH and 1O2 were dominant. Meanwhile, the electron transfer and synergistic catalysis between Ce and Fe promoted the regeneration of the metal active site, which was beneficial to improve the reuse stability of the Ce/Fe@C-CA cathode. The degradation pathway of CAP was obtained by DFT calculations and UPLC-MS/MS detection. This study not only proposed a novel bifunctional electro-Fenton cathode, but also provided a effective strategy for the treatment of actual pharmaceutical wastewater.

Photochemical-promoted ZVI reduction for highly efficient removal of 4-chlorophenol and Cr(VI): Catalytic activity, performance and electron transfer mechanisms

Zero-valent iron (ZVI) reduction represents a promising methodology for water remediation, but its broad application is limited by two critical challenges (i.e., aggregation and passivation). Here, we report a hybrid strategy of photochemical-promoted ZVI reduction with high efficiency and reduction capacity for removing coexisting refractory pollutants in water. A composite material with Pd/Fe bimetallic nanoparticles supported onto semiconducting metal oxide (Pd/Fe@WO3-GO) was prepared and subsequently used as the model catalyst. By using the developed strategy with visible light as light source, this catalyst showed a remarkable catalytic performance for simultaneously eliminating 4-chlorophenol (4-CP) and Cr(VI), with dehalogenation rate as high as 0.43 min−1, outperforming the reported ZVI-based catalysts. A synergistic interaction of photocatalysis and ZVI reduction occurred in this strategy, where the interfacial electron transfer on particles surface were greatly strengthened with light irradiation. The activation was attributed to the dual functions of semiconducting material as support to disperse Pd/Fe nanoparticles and as (photoexcited) electron donor to directly trigger reduction reactions and/or indirectly inhibit the formation of oxides passivation layer. Both direct electron transfer and H*-mediated indirect electron transfer mechanisms were confirmed to participate in the reduction of pollutants, while the later was quantitatively demonstrated as the predominant reaction route. Importantly, this strategy showed a wide pH applicability, long-term durability and excellent catalytic performance in different real-water systems. This work provides new insights into ZVI reduction and advances its applications for the removal of combined organic and inorganic pollutants. The developed photochemical-promoted ZVI reduction strategy holds a great potential for practical applications.

Amidative β-Scission of Alcohols Enabled by Dual Catalysis of Photoredox Proton-Coupled Electron Transfer and Inner-Sphere Ni-Nitrenoid Transfer.

The photoredox/Ni dual catalysis is an appealing strategy to enable unconventional C-heteroatom bond formation. While significant advances have been achieved using this system, intermolecular C(sp3)-N bond formation has been relatively underdeveloped due to the difficulty in C(sp3)-N reductive elimination. Herein, we present a new mechanistic approach that utilizes dioxazolones as the Ni(II)-nitrenoid precursor to capture carbon-centered radicals by merging proton-coupled electron transfer (PCET) with nickel catalysis, thus forming synthetically versatile N-alkyl amides using alcohols. Based on mechanistic investigations, the involvement of (κ2-N,O)Ni(II)-nitrenoid species was proposed to capture photoredox PCET-induced alkyl radicals, thereby playing a pivotal role to enable the C(sp3)-N bond formation.

Green fabrication of high-performance silver nanoparticles/reduced Ti3C2T x MXene nanocomposite catalyst for 4-nitrophenol reduction

The outstanding electrical conductivity of transition metal carbides Ti3C2T x (MXene) makes it as an excellent electron transfer medium for fabrication of efficient catalysts. However, the poor stability of MXene may restrict its application. Herein, a novel silver nanoparticles/reduced MXene nanocomposite (AgNPs/rMXene) catalyst was prepared by using L-arginine (L-Arg) as a green reducing agent. In the AgNPs/rMXene catalyst, the silver nanoparticles (AgNPs) and reduced MXene (rMXene) acted as catalytic active species and electron transfer medium, respectively. The composite catalyst exhibited superior catalytic activity in the conversion of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP), and the conversion frequency (TOF) was high up to 1109.4 h−1. Notably, the composite catalyst also showed high stability due to the reduction of L-Arg (i.e. the repair of defect groups on MXene surface). The conversion efficiency for 4-NP reduction by AgNPs/rMXene was high up to 90% after five recycles. This present study offers a simple and green approach for the design and development of efficient MXene-based catalysts.

NiFe Nanoparticle Nest Supported on Graphene as Electrocatalyst for Highly Efficient Oxygen Evolution Reaction.

Designing cost-efffective electrocatalysts for the oxygen evolution reaction (OER) holds significant importance in the progression of clean energy generation and efficient energy storage technologies, such as water splitting and rechargeable metal-air batteries. In this work, an OER electrocatalyst is developed using Ni and Fe precursors in combination with different proportions of graphene oxide. The catalyst synthesis involved a rapid reduction process, facilitated by adding sodium borohydride, which successfully formed NiFe nanoparticle nests on graphene support (NiFe NNG). The incorporation of graphene support enhances the catalytic activity, electron transferability, and electrical conductivity of the NiFe-based catalyst. The NiFe NNG catalyst exhibits outstanding performance, characterized by a low overpotential of 292.3mV and a Tafel slope of 48mVdec-1, achieved at a current density of 10mAcm- 2. Moreover, the catalyst exhibits remarkable stability over extended durations. The OER performance of NiFe NNG is on par withthat of commercial IrO2 in alkaline media. Such superb OER catalytic performance can be attributed to the synergistic effect between the NiFe nanoparticle nests and graphene, which arises from their large surface area and outstanding intrinsic catalytic activity. The excellent electrochemical properties of NiFe NNG hold great promise for further applications in energy storage and conversion devices.

Versatile biomimetic catalyst functionalized nanozymes for electrochemical sensing

Electrochemical sensors face challenges in the readily accessible versatile sensing materials, robust signal transmission and selective detection of analytes in complex systems. Herein, we report a simple one-pot approach using commercially available materials to synthesize versatile biomimetic catalyst functionalized nanozymes for multifunctional electrochemical sensors. Nanoenzymes were synthesized by in situ polymerization of 3,4-ethylenedioxythiophene (EDOT) on graphene (GR) while integrating biomimetic catalysts into nanosheets. The resulting nanozymes exhibited stable and efficient catalysis activity and interfacial signal transmission through electrostatic and π-π interactions, as well as charge transfer at the active centers. By virtue of excellent electron transfer and favorable cascade catalysis effect, the biosensor based on sulfonated cobalt phthalocyanine functionalized nanozymes (CoPcNS) and acetylcholinesterase (AChE) exhibited superior catalytic activity and robust stability. This one-pot method was also used to prepare nanozymes with diverse biomimetic catalysts (metallophthalocyanine and metalloporphyrin), achieving specific detection of various biomolecules (H2O2, NO, etc.). A portable biosensing device based on a screen-printed electrode was developed, featuring a low limit of detection, ultralow working potential, high anti-interference capability, and good applicability for the rapid detection of organophosphorus pesticides (OPs) in real samples. Our research presents a promising guide for the rational fabrication of versatile biomimetic catalyst-functionalized nanozymes, advancing the development of electrochemical sensors in environmental and biological fields.

Identification of hydrogen bonding network for proton transfer at the quinol oxidation site of Rhodobacter capsulatus cytochrome bc1

Cytochrome bc1 catalyzes electron transfer from quinol (QH2) to cytochrome c in reactions coupled to proton translocation across the energy-conserving membrane. Energetic efficiency of the catalytic cycle is secured by a two-electron, two-proton bifurcation reaction leading to oxidation of QH2 and reduction of the Rieske cluster and heme bL. The proton paths associated with this reaction remain elusive. Here we used site-directed mutagenesis and quantum mechanical (QM) calculations to analyze the contribution of protonable side chains located at the heme bL side of the quinol oxidation site (Qo) in Rhodobacter capsulatus cytochrome bc1. We observe that the proton path is effectively switched off when H276 and E295 are simultaneously mutated to the non-protonable residues in the H276F/E295V double mutant. The two single mutants, H276F or E295V, are less efficient, but still transfer protons at functionally-relevant rates. Natural selection exposed two single mutations, N279S and M154T, that restored the functional proton transfers in H276F/E295V. QM calculations indicated that H276F/E295V traps the side chain of Y147 in a position distant from QH2, while either N279S or M154T induce local changes releasing Y147 from that position. This shortens the distance between the protonable groups of Y147 and D278 and/or increases mobility of the Y147 side chain, which makes Y147 efficient in transferring protons from QH2 toward D278 in H276F/E295V. Overall, our study identified an extended hydrogen bonding network, build up by E295, H276, D278 and Y147, involved in efficient removal of the proton from QH2 at the heme bL side of Qo.

Vanadium in the Environment: Biogeochemistry and Bioremediation.

Vanadium(V) is a highly toxic multivalent, redox-sensitive element. It is widely distributed in the environment and employed in various industrial applications. Interactions between V and (micro)organisms have recently garnered considerable attention. This Review discusses the biogeochemical cycling of V and its corresponding bioremediation strategies. Anthropogenic activities have resulted in elevated environmental V concentrations compared to natural emissions. The global distributions of V in the atmosphere, soils, water bodies, and sediments are outlined here, with notable prevalence in Europe. Soluble V(V) predominantly exists in the environment and exhibits high mobility and chemical reactivity. The transport of V within environmental media and across food chains is also discussed. Microbially mediated V transformation is evaluated to shed light on the primary mechanisms underlying microbial V(V) reduction, namely electron transfer and enzymatic catalysis. Additionally, this Review highlights bioremediation strategies by exploring their geochemical influences and technical implementation methods. The identified knowledge gaps include the particulate speciation of V and its associated environmental behaviors as well as the biogeochemical processes of V in marine environments. Finally, challenges for future research are reported, including the screening of V hyperaccumulators and V(V)-reducing microbes and field tests for bioremediation approaches.

Radical thioesterification via nickel-catalysed sensitized electron transfer

Multi-catalytic reaction modes have attracted widespread attention in synthetic chemistry. The merger of nickel catalysis with photoredox catalysis has offered a powerful platform for synthesis of molecules with attractive properties. Nonetheless, the conceptual development of nickel-catalysed, sensitized electron transfer is of pivotal relevance, but is still greatly limited. Here we describe the development of a radical cross-thioesterification process by nickel-catalysed sensitized electron transfer. The strategy can produce diverse methyl thioesters, which are not only found in natural products, materials and pharmaceuticals but also are widespread precursors in synthetic chemistry and biological processes. This catalytic mode features high chemoselectivity, good functional group tolerance and excellent scalability. Perhaps more important was the finding that various drugs and amino acids were successfully functionalized in this system. Experimental studies, nanosecond transient spectroscopic analysis, and density functional theory calculations reveal that the merger of photocatalytic electron transfer, energy transfer and nickel catalysis plays an essential role in this radical thioesterification reaction.

Electrochemically Driven Hydrogen Atom Transfer Catalysis: A Tool for C(sp3)/Si-H Functionalization and Hydrofunctionalization of Alkenes.

Electrochemically driven hydrogen atom transfer (HAT) catalysis provides a complementary approach for the transformation of redox-inactive substrates that would be inaccessible to conventional electron transfer (ET) catalysis. Moreover, electrochemically driven HAT catalysis could promote organic transformations with either hydrogen atom abstraction or donation as the key step. It provides a versatile and effective tool for the direct functionalization of C(sp3)-H/Si-H bonds and the hydrofunctionalization of alkenes. Despite these attractive properties, electrochemically driven HAT catalysis has been largely overlooked due to the lack of understanding of both the catalytic mechanism and how catalyst selection should occur. In this Review, we give an overview of the HAT catalysis applications in the direct C(sp3)-H/Si-H functionalization and hydrofunctionalization of alkenes. The mechanistic pathways, physical properties of the HAT mediators, and state-of-the-art examples are described and discussed.

The integration of both advantages of cobalt-incorporated cancrinite-structure nanozeolite and carbon nanotubes for achieving excellent electrochemical oxygen evolution efficiency

A novel composite electrocatalytic material (CoZ@xCNT), composed of Cobalt-injected cancrinite-structure nanozeolite (CoZ) and carbon nanotubes (CNT), was synthesized successfully. The CoZ was found to possess a cancrinite crystal structure and exhibit nanorod-like morphology. The tight binding between CoZ and CNT was beneficial for the electron transfer. The high-efficiency oxygen evolution reaction (OER) catalytic electrodes (CoZ@xCNT@CC) were prepared, and CoZ@1CNT@CC displayed the largest electrochemical active area, low overpotential of 277 mV and Tafel slope of 86.5 mV·dec−1, and acceptable electrochemical catalytic stability. The combination of CoZ's catalytic ability and CNT's electron transfer ability should contribute to excellent OER catalytic performance.

Carbon nanomaterials and their composites for electrochemical glucose biosensors: A review on fabrication and sensing properties

BackgroundWith the increasing prevalence of diabetes that increases the risk of cardiovascular diseases, kidney failure, nerve degeneration, eye damage, lower extremity amputations and birth defects, the demand for highly efficient glucose sensors has attracted significant attention worldwide. In this regard, carbon nanomaterials-based electrochemical glucose sensors have shown great potential in the detection and monitoring of glucose. MethodsDifferent forms of carbon such as carbon nanotubes, graphene, reduced graphene oxide, carbon nanofibers, activated and amorphous carbon, carbon spheres, carbon nanoparticles, carbon quantum dots, carbon nanorods, carbon nanocages etc. and their hybrids have been extensively researched for highly efficient glucose sensors due to their large surface area, porosity, lightweight, thermal stability, excellent mechanical properties, ease of fabrication, high electrical conductivity, excellent catalytic properties and fast electron transfer kinetics. Significant findingsDue to their large surface area and tunable porosity, carbon nanomaterials have been used as a scaffold for the immobilization of large quantities of bioreceptor units such as enzymes and highly catalytic metal or metal oxide nanostructures, which can enhance the electroanalytical properties of the biosensor. In this review paper, the fabrication and electroanalytical properties of carbon nanomaterials based enzymatic and nonenzymatic electrochemical glucose sensors have been reviewed and their sensing mechanisms are discussed.