Electrochemical Oxidation Of Glucose Research Articles

Hybrid catalyst cascade for enhanced oxidation of glucose in glucose/air biofuel cell

Redox enzymes are capable of harvesting electrical energy from biofuels in high catalytic activity and under mild condition. However, it is difficult to achieve efficient electron transfer and deep oxidation of biofuels simultaneously in a single-enzyme catalytic system. Herein, we report a hybrid catalyst cascade consisting of an organic oxidation catalyst, 2,2,6,6-tetramethyl-1-piperidine N-oxyl (TEMPO), and an enzyme, glucose oxidase (GOx), for electrochemical oxidation of glucose. It is found that TEMPO is capable of mediating electron transfer between the redox center of GOx and the electrode surface. While glucose can be oxidized into glucuronic acid under neutral conditions. Thus, combining GOx and TEMPO, we are able to achieve 4e- electrooxidation of glucose using the hybrid enzymatic and organic cascade (HEOC) system. When coupled with an air-breathing Pt cathode, the resulting glucose/air biofuel cell using the proposed HEOC anode exhibits a maximum power density of 38.1 μW cm−2 with a short-circuit current of 651.4 μA cm−2, which can be attributed to the enhanced energetic efficiency, enabling TEMPO a promising catalyst for glucose oxidation in bioelectronics applications.

Iron, Nitrogen-Doped Carbon Aerogels for Fluorescent and Electrochemical Dual-Mode Detection of Glucose.

Due to their effective catalytic activity and maximum atom utilization, single metal atoms dispersed in carbon matrices have found diverse applications in electrocatalysis, photocatalysis, organic catalysis, and biosensing. Herein, iron is atomically dispersed into nitrogen-doped porous carbon aerogel by a facile pyrolysis procedure, and the resulting nanocomposite behaves both as a peroxidase mimic for the sensitive detection of glucose by fluorescence spectroscopy and as an effective catalyst for the electrochemical oxidation of glucose. The glucose concentration can be quantified within the millimolar to micromolar range with a limit of detection of 3.1 and 0.5 μM, respectively. Such a dual-functional detection platform also shows excellent reproducibility, stability, and selectivity, and the performance in glucose detection of clinical and artificial human body fluids is highly comparable to that of leading assays in recent studies and results from commercial sensors. Results from this study suggest that carbon aerogel-supported single atoms can be used as a dual-functional nanozyme for the construction of low-cost, high-performance dual-signal readout platforms for glucose detection.

Design of transition metal oxides nanosheets for the direct electrocatalytic oxidation of glucose

The design of the morphology-controlled synthesis of two-dimensional (2D) transition metal oxides nanomaterials is a key for electrochemical oxidation of glucose. Herein, a general preparation method is adopted to develop a variety of transition metal oxides nanosheets, including cobalt oxide nanosheets (Co3O4 NS), nickel oxide nanosheets (NiO NS), copper oxide nanosheets (CuO NS), and iron oxide nanosheets (Fe3O4 NS) through a chemical reduction method followed by a hydrothermal strategy. The surface morphological characterization is performed by using transmission electron microscopic (TEM), high resolution transmission electron microscopic (HRTEM), and atomic force microscopic (AFM) measurements, revealed the two-dimensional nanosheets-like metal oxides formed. The as-developed transition metal oxide nanosheets are employed as electrocatalysts for the improved oxidation of glucose under alkaline electrolyte. The NiO nanosheets delivers best catalytic current density of ~3.1 mA cm−2 which is over- ~1.7- and ~2.6- times higher with a less positive potential, respectively in comparison to Co3O4 nanosheets and CuO nanosheets based electrodes. The morphological engineered two-dimensional nanosheets exhibit high electrochemical active sites, fast electron transfer kinetics, etc. towards the glucose oxidation reaction (GOR).

Synthesis of copper oxides-graphene composites for glucose sensing

A multi-gram preparation of graphene nanoplatelets decorated with CuO leaf-like structures and Cu2O nanocubes can be accomplished with ease from graphite using an environmentally friendly method. The composites' synthesis is conveniently achieved within an hour through a high shear mixing pre-treatment of the graphite in water, followed by the addition of copper salts to the resulting slurry and their subsequent conversion to cupric or cuprous oxide-few layer graphite composites of varying weight ratios. The materials, characterized by XRD, Raman, SEM, TEM, and TGA exhibit good electrochemical glucose oxidation sensing capacity. Cyclic voltammetry of modified glassy carbon electrodes prepared with a 1:0.2 weight ratio of graphene nanoplatelets to CuO or Cu2O composites shows low detection limits of 0.25 μM (S/N = 3) for glucose and high sensitivities of 845 and 1,108 μA cm–2 mM–1, respectively. The sensors also show exceptionally low current response to the commonly found interferents such as uric acid, dopamine, and ascorbic acid. The materials' ease of manufacturing and good sensing capabilities suggests their potential use in determining glucose contents in biological samples and industrial applications.

A facile method for the fabrication of hierarchically structured Ni2CoS4 nanopetals on carbon nanofibers to enhance non-enzymatic glucose oxidation.

Unique Ni2CoS4-carbon nanofiber (CNF) composite nanostructures were fabricated using a simple electrospinning-assisted hydrothermal route and used for the rapid and accurate electrochemical oxidation of glucose in real samples at the trace level. Electrochemical impedance spectroscopy and cyclic voltammetry of unmodified and modified electrodes revealed low charge-transfer resistance and the excellent electrocatalytic sensing of glucose when using the Ni2CoS4-CNF at a low potential due to the combined benefits of the highly conductive Ni2Co2S4 anchored to the large surface area of the CNFs. Amperometric analysis of the fabricated sensor has shown an extremely low limit of detection (0.25nM) and a large linear range (5-70nM) for glucose at a working potential of 0.54V (vs. Hg/HgO). The practicability of the Ni2CoS4-CNF for use in glucose determinationwas tested withl human saliva, blood plasma, and fruit juice samples. The Ni2CoS4-CNF/GCE showed acceptable recovery values for human saliva (99.1-100.8%), blood plasma (98.6-101.5%), and fruit juice (95.1-105.7%) samples. The proposed sensor also exhibited outstanding electroanalytical characteristics for glucose oxidation in these samples, including reusability, repeatability, and interference resistance, even in the presence of other biological substances and organic and inorganic metal ions.

Facile Nonenzymatic Glucose Electrode Composed of Commercial CuO Powder and Ionic Liquid Binder

Commercially available micro-sized CuO powder was dispersed in the mixture of ethanol and protonated betaine bis((trifluoromethyl)sulfonyl)amide ([Hbet][TFSA]), a hydrophobic amide-type protic ionic liquid (IL), to prepare a composite paste for the modification of screen-printed carbon electrode (SPCE) via spin-coating. The fabricated SPCE\CuO−IL composite-based electrode showed a comparable activity as that of the nanonized metal-oxide based electrodes towards the electrochemical oxidation of glucose in alkaline solutions. Hydrodynamic chronoamperometry tests performed at +0.55 V showed a linear dynamic response of the electrode over the concentration range of 1 μM–2.8 mM with a sensor-sensitivity of 0.16 μA μM−1 in 0.1 M NaOH. The data also showed a linear dynamic response over the concentration range of 1 μM–4.6 mM with a sensor-sensitivity of 0.10 μA μM−1 in 0.1 M NaOH with 0.1 M NaCl, indicating that the major interferant Cl− had negligible effects on glucose detection . Ascorbic acid (AA) (in the physiological level) and ethanol also did not interfere with the detection. Detection of glucose in real samples showed the recovery ratios higher than 95 %. This study has clearly demonstrated that commercial CuO powder without nanostructure can provide sufficient reactivity to the electrocatalytic oxidation of glucose by using IL as the organic binder. Facile preparation of the micro-sized metal oxide-modified electrodes can be accordingly pursued.

In situ synthesis of PANI/CuO nanocomposites for non-enzymatic electrochemical glucose sensing

We report the in situ synthesis of polyaniline/copper oxide (PANI/CuO) nanocomposites and their characterization as electrocatalyst for non-enzymatic electrochemical glucose detection. Copper oxide (CuO) nanoparticles were prepared by wet chemical precipitation method followed by thermal treatment while the composites of PANI and CuO were synthesized by in situ chemical polymerization of aniline with definite amount of CuO. X-ray diffraction (XRD) results revealed that the composites are predominantly amorphous. The composite formation was confirmed by fourier transform infrared (FTIR) and UV-Vis spectroscopy analysis. The surface morphology was greatly altered with the amount of CuO in composite structure. PANI/CuO nanocomposites were coated on copper substrate to investigate their electrocatalytic activity for glucose sensing. PANI/CuO with 10 wt. % CuO exhibited good response towards electrochemical glucose oxidation.

Enhanced electrochemical glucose oxidation in alkaline solution over indium decorated carbon supported palladium nanoparticles

At present, carbon nanotube (CNT) supported In modified Pd catalysts are prepared at varying Pd:In ratios via NaBH4 reduction method to investigate the synergetic effect of Pd and In monometallic catalysts through glucose electrooxidation. These catalysts are characterized by advanced surface analytical techniques, namely, inductively coupled plasma-mass spectrometry (ICP-MS) with Agilent 7800 ICP-MS, N2 adsorption-desorption measurements (BET) with Micromeritics 3Flex equipment Tristar II 3020 equipped, PANalytical Empyrean device-ray diffractometer (XRD), Hitachi HighTech HT7700 high resolution-transmission electron microscope (HR-TEM), and scanning electron microscope (SEM). Electrochemical measurements are performed by using cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) by CHI660E potentiostat in a three electrode system. The characterization results show that all catalysts are successfully synthesized at desired molar composition. For PdIn (90:10)/CNT catalyst, the crystal size obtained from HR-TEM is 2.36 nm and BET surface area is 212.28 cm2g-1.5% PdIn(90:10)/CNT catalyst exhibits the best catalytic activity, lowest charge transfer resistance (Rct), and a long term stability compared to Pd, In, other Pd:In bimetallic catalysts. EIS and CA results are in a good agreement with CV results.

The effect of reaction layer composition on Pt/NiO function for glucose oxidation reaction in neutral media.

This study shows the application of carbon supported electrodes containing Pt/NiO nanoparticles to catalyze the electrochemical oxidation of glucose in neutral media. In particular, this study describes the effect of the Pt content and type of carbon (carbon black, expanded graphite, or charcoal active) in the reaction layer on this oxidation process in neutral media. Pt/NiO nanoparticles were synthesized by a simple hydrothermal method, and further characterized by scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), and cyclic voltammetry. These nanoparticles were used to modify carbon electrodes. The effectiveness of these electrodes for electrochemical glucose oxidation was evaluated. The results revealed that the catalytic activity of the electrodes depends on the content of Pt/NiO nanoparticles and the type of carbon. The 10% Pt/NiO with 90% loading (use of activated charcoal in the reaction layer) as optimum electrode indicated good stability after 1200 voltammetry cycles. This modified electrode was highly active for glucose oxidation in neutral media, which could be attributed to the presence of Pt/NiO nanoparticles as catalyst and high surface area of activated charcoal on the electrode surface.

Investigation of Glucose Oxidation on Gold Nanocrystallites Modified Cobalt and Cobalt-Boron Coatings

Herein, the electrochemical oxidation of glucose has been investigated on the Co and CoB alloy coatings, which were deposited on the copper substrate (Cu) and subsequently modified with a small amount of Au nanocrystallites (termed as the AuCo/Cu and AuCoB/Cu catalysts), with the aim to use them as the anode catalysts for direct glucose fuel cells (DGFCs). The catalysts have been prepared via a simple electroless Co deposition method followed by a spontaneous Au galvanic displacement from the Au(III)-containing solution. The activity of the prepared catalysts for the oxidation of glucose in an alkaline medium has been examined by cyclic voltammetry and chrono-techniques.In conclusion, the Co and CoB alloy coatings, which were modified with a small amount of Au nanocrystallites in the range from 11 to 14 µg Au cm–2, exhibit a significantly higher activity for the oxidation of glucose as compared to that of bare Au, Co and CoB alloy catalysts. Furthermore, the process of glucose oxidation has been significantly shifted to more negative potential domain at the both AuCo/Cu and AuCoB/Cu catalysts, indicating the higher activity of the latter catalysts as compared to that of the unmodified Co/Cu and CoB/Cu catalysts and the bare Au electrode. In addition, approximately 22 and even 67 times higher glucose oxidation current density values have been obtained at the AuCo/Cu and AuCoB/Cu catalysts, respectively, as compared to those for the unmodified CoB/Cu and Co/Cu. The prepared AuCo/Cu and AuCoB/Cu catalysts, which have been prepared with very small amount of Au nanocrystallites, seem to be a promising anode material for DGFCs.

Mediated electrochemical oxidation of glucose via poly(methylene green) grafted on the carbon surface catalyzed by flavin adenine dinucleotide-dependent glucose dehydrogenase

Electrochemically polymerized phenothiazines (thionine, methylene green, methylene blue, and toluidine blue) on carbon electrodes were investigated as electron transfer mediators of glucose oxidation by flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) for biosensor and biofuel cell applications. Among the tested polyphenothiazines grafted on a glassy carbon electrode, clear redox-mediating activity was observed for poly(methylene green), and the catalytic oxidation current depended on the concentrations of glucose and enzymes and the amount of polymer deposited on the electrode surface. The poly(methylene green)-grafted porous carbon electrodes showed 3 mA cm−2 of glucose oxidation current catalyzed by FAD-GDH.

Toward an ideal platform structure based on MgO-templated carbon for flavin adenine dinucleotide-dependent glucose dehydrogenase-Os polymer-hydrogel electrodes

For the efficient electrochemical glucose oxidation on the electrode modified with redox hydrogel involving Os-tethered polymer and flavin adenine dinucleotide-dependent glucose dehydrogenase (FADGDH), the effect of pore size of MgO-templated carbon (MgOC) as an electrode material was studied. The MgOC was modified on glassy carbon electrode by ink-drop-casting technique. The MgOC pore size clearly affected on the current generation efficiency for glucose oxidation. As the pore size increased above 100 nm, a glucose oxidation current density of more than 100 mA cm−2 was achieved with 1000 μg cm−2 of hydrogel loading. Both high specific surface area and macrostructure of MgOC, which does not impede mass transport even if hydrogel loading is increased, are important factors in designing the porous structure of the MgOC layer via the ink-drop-casting process during electrode fabrication.

Composites of Reduced Graphene Oxide/Nickel Submicrorods for Non-Enzymatic Electrochemical Biosensing: Application to Amperometric Glucose Detection

For the rapid detection of hyperglycemia in human blood, we adopted a facile and two-step electrochemical procedure to prepare nickel/reduced graphene oxide (rGO) hybrid electrodes in the framework of a three-dimensional (3D) nanostructure. High-density and vertically-aligned nickel submicrorods with an average diameter of 155 ± 15 nm and a length of 7 ± 1 μm (an aspect ratio of about 40–50) were prepared by template-mediated electrochemical deposition techniques. Networks of rGO nanosheets between the rod-shaped arrays were formed by the cathodic electrophoretic deposition method. The synergistic effect of nickel morphology (planar and high-density rod-shaped arrays) and graphene oxide nanosheets on the electrochemical glucose oxidation in both simulated and real samples (human blood serum) were studied. It is shown that the higher surface area of Ni submicrorods significantly enhances the sensitivity of glucose detection by 6-fold (659.5 μA mM−1 cm−2) as compared with planar Ni (113 μA mM−1 cm−2) while the limit of detection (LOD at S/N = 3) is reduced by ∼62% (from 0.13 mM to 0.05 mM). In the presence of reduced graphene oxide nanosheets, enhanced surface contacts between the metal submicrorods and the carbon nanostructure facilitate electron transfer through surface OH− motifs, further improving the sensitivity to 7121 μA mM−1 cm−2. A better LOD (0.5 μM) is also attained. The application of the electrode for glucose detection in human blood serum, i.e., fast detection (<3 s) with relatively high precision (94% confidence), is demonstrated.

Mucilage-capped silver nanoparticles for glucose electrochemical sensing and fuel cell applications.

A simple, cost-effective and green mucilage-capped silver nanoparticles (Mucilage-AgNPs) modified glassy carbon electrode (GC) composite was constructed for efficient and facile electrochemical oxidation of glucose for the first time. Mucilage-AgNPs were synthesized through the direct chemical reduction of Ag+ by mucilage extracted from Opuntia ficus-indica. Mucilage-AgNPs were identified and characterized using ultraviolet-visible spectroscopy, transmission electron microscopy and square wave voltammetry. Modification of the GC with AgNPs was carried out via a transfer-sticking technique with an immobilization time of 1 h. The Mucilage-AgNPs/GC composite was studied as a possible anode for glucose oxidation in a biofuel cell. The composite resulted in glucose oxidation with a current density and power density of 85.7 μA cm−2 and 25.7 μW cm−2, respectively. Glucose sensing using the Mucilage-AgNPs/GC composite was achieved successfully via two pathways: glucose oxidation and AgNP inhibition. The glucose oxidation-based sensor showed a lower detection limit of 0.01 mM and a linear range of 0.01 to 2.2 mM. The AgNPs inhibition-based sensor provides an indirect determination pathway of glucose with a detection limit of 0.1 mM and a linear range of 0.1 to 1.9 mM. AgNP inhibition is a novel pathway that could be used for determining a large number of organic and inorganic molecules. Overall, the Mucilage-AgNPs/GC is considered a pioneering composite for glucose sensing and fuel cell applications.

A novel enzyme-free FI-amperometric glucose biosensor at Cu nanoparticles modified graphite pencil electrode

In this work, graphite pencil electrode (GPE) was modified with Cu nanoparticles (CuNPs) for enzyme-free flow injection (FI) amperometric detection of glucose. To modify electrode, CuNPs were electrodeposited onto GPE surface by recording 10 successive cyclic voltammograms (CVs) of 2.0 mM Cu(NO3)2 in 100 mM KNO3. The electrochemical characterizations of the electrodes were realized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry techniques. The SEM images and EDX spectra of the pencil leads were recorded to investigate the surface morphologies of the electrodes. Then, the electrochemical response of both unmodified GPE and CuNPs/GPE towards electrochemical oxidation of glucose was performed by recording CVs in the supporting electrolyte consisted of 100 mM NaOH and 100 mM KCl. CVs recorded at GPE showed that the electron transfer rate of glucose is relatively slow and oxidation of glucose irreversibly observed with very low current at a high positive potential (+0.70 V). On the other hand, glucose oxidized at more negative potential value (+0.45 V) than that of unmodified GPE with a view of sharp peak at CuNPs/GPE. These results show that CuNPs/GPE exhibits excellent electrocatalytic activity and high electrochemical response towards oxidation of glucose because electron transfer rate of glucose was remarkably enhanced by modification of GPE with CuNPs. In the flow injection (FI) amperometric experiments, +0.45 V and 2.5 mL/min were used as optimal values for applied potential (Eap) and flow rate (fr), respectively. A linear calibration curve was obtained in the range from 0.10 to 400 µM glucose with a detection limit and sensitivity of 0.04 µM and 0.830µA µM−1 cm−2, respectively. The selectivity of glucose sensor was tested in the presence of various interferences. At last step, constructed glucose biosensor was successfully tested on some real glucose samples.

Nanorods of Bi–Co–S for Electrocatalysis of Glucose Oxidation and Hydrogen Evolution

Abstract In order to develop a non-precious metal-based catalyst, Bi–Co–S nanorods were prepared by a simple solvothermal method. The morphology and composition were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectrometer (EDXS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry and chronoamperometry were used to study the electrochemical oxidation of glucose in alkaline medium. Bi–Co–S nanorods with different ratio of Bi/Co were modified on the electrode and their electrocatalytic activities were compared. The results showed that Bi–Co–S nanorods with the 1:2 ratio of Bi/Co exhibited the lowest initial potential and the highest catalytic current. In addition, Bi–Co–S nanorods showed long-term durability. The introduction of Co significantly improves the catalytic activity of the catalyst, and the excellent performance of Bi–Co–S nanorods may be due to the synergy between the two sulfides.

Self-formed nanocatalyst layers on Ni–Cu alloy substrates and their characteristics for electrochemical glucose oxidation

This paper proposes a simple method for the preparation of metallic nanocatalyst layers on alloy substrates. Versatile, commercially available Ni–Cu alloy substrates were heat-treated at relatively low temperatures, and the self-formed surface oxide layers were examined for use as electrocatalysts for glucose oxidation. The alloy substrate that was preheated at 400 °C for 1 h under atmospheric conditions exhibited effective improvement in its onset potential for electrochemical glucose oxidation under alkaline conditions. Furthermore, detailed surface characterization of each preheated substrate was also conducted to identify the associated catalyst species.

Electrochemical Characterization of Carbonized Typha Tassel Modified ScreenPrinted Electrode and Its Enzymatic Glucose Oxidation Application

Converting biomass into cheaper but valuable products is very important for a more sustainable world. Especially with&#x0D; emerging technology, the use of hazardous materials in the synthesis of substances such as carbonaceous materials pose&#x0D; a threat to our environment. In this study, electrochemical performance of a carbonaceous material synthesized from typha&#x0D; tassel using a simple and cheap method without any hazardous substances was investigated. It was then used as an enzyme&#x0D; immobilization material for electrochemical glucose oxidation to demonstrate its potential application in bioelectronics. Physical and chemical characterization of raw typha tassel (RTT) and carbonized typha tassel (CTT) were performed using SEM&#x0D; and FTIR techniques. CTT, was then grounded into fine powder, dispersed in DMF and coated onto screen-printed electrodes&#x0D; (SPEs). CTT modified SPEs were electrochemically tested using cyclic voltammetry in 0.1 M phosphate buffer containing 1&#x0D; mM ferrocene carboxylic acid as a redox mediator at pH 7.4 Finally, glucose oxidase enzyme was adsorbed on CTT modified&#x0D; SPEs to demonstrate its performance in electrochemical enzymatic glucose oxidation reactions. SPE/CTT/GOx system showed&#x0D; promising electrochemical activity and stability at physiological conditions as well as good activity with adsorbed enzyme. This&#x0D; study suggests that CTT is very promising for an easy, effective and cheap ‘biomass to bioelectronics’ construction material

Development of NiO-Nanocarbon and MnO2-Nanocarbon Energetic Catalytic Electrode Materials to Synthesize Electrical Energy through Electrochemical Oxidation of Glucose

Automobile and transportation on land and in air are the major causes of global environment pollution through the chemical combustion of petroleum fuels. The need of the hour is to run the transportation units by fuel cells which convert fuels to energy through electrochemical oxidation, straight to pure electrical energy with no polluting substances. Development of fuel cell lies on exhaustive research on development of high energetic electrocatalytic electrodes over which the fuels break to produce free electron and ions, delivering electrical energy. The present work aims at developing two electrocatalytic materials: NiO-nanocarbon and MnO2-nanocarbon by electrosynthesis method. The performance of the materials was investigated by electrochemical characterization: cyclic voltammetry, chronoammetry, polarization tests and impedance spectroscopy. The materials were found to deliver a high current on electro-oxidation of glucose. The effect of nanocarbon on NiO and MnO2 has enhanced the current to a level of over 100 mA/cm2. XRD study showed the presence of metal oxides and carbon. The electron microscopy images revealed fine grain oxides with entrapped nanocarbon. The carbon seems to be in the form of graphene, produced during electrochemical exfoliation at anode. The SEM morphology of enhanced 3D surface area with high energetic nanocarbon phase entrapped with fine structure metal oxides accounts for the high current obtained by electro-oxidation of the fuel. The materials developed are found to be very good energetic electrodes for future fuel cell in automotive industry.

Developing High-Performance Non-Enzymatic Glucose Sensors Based on Transition Metal Chalcogenides

Diabetes has long been recognized as one of the leading causes of death in the United States and worldwide second only to cancer and heart-related ailments. Diabetes is a silent killer and early stage diagnosis and controlling blood glucose level is the key to maintain and control the disease. Blood glucose levels are typically monitored with the help of glucose detection through electrochemical oxidation of glucose to gluconic acid or gluconolactone. Typically, in conventional glucose detectors, enzyme-based electrochemical sensors are used which suffers from several critical challenges including reduced efficiency and sensitivity, reduced shelf lives, lack of long-term stability (due to enzyme denaturation), high fabrication cost (due to complex enzyme purification steps), and high detection limit (due to less efficient indirect electron transfer). In this presentation we will discuss about designing high-efficiency direct glucose electrochemical sensors from transition metal chalcogenides using principles of materials chemistry, specifically, tuning the redox potential of the transition metal site. We will present several examples of high-efficiency chalcogenide based glucose sensors including CoNi2Se4-rGO nanocomposite, Ni3Te2, Cu2Se, and NiSe. These chalcogenide based electrocatalysts show high activity for glucose oxidation at very low potential (~0.35 - 0.45 V vs Ag|AgCl) with high sensitivity (exceeding 18 mA/mM cm2) and low limit of detection (LOD). These chalcogenides can offer direct electron transfer pathways over a wide potential range leading to much higher sensor efficiency. Moreover, the sensing performance of these electrocatalysts were tested in presence of common interferents present in physiological samples such as dopamine, ascorbic acid, lactose, etc., where it showed that glucose sensing was unaffected primarily because at such low potential, other biomolecules are not affected. In fact, the ability to oxidize glucose at such low potential is considered to be one of the most prominent novelty of these chalcogenide electrocatalysts, and the glucose oxidation potential of 0.35V (CoNi2Se4) is one of the lowest reported potential till date. The reason for such high activity for glucose oxidation was investigated through a series of experiments designed to alter the redox potential of the transition metal site either by changing the anion (selenide to telluride), transition metal doping (NiSe vs CoNi2Se4), or changing the d-electron occupancy (NiSe vs Cu2Se). Through these measurements we observed that on changing the electronegativity of the anion from selenide to telluride, the glucose oxidation potential could be reduced further due to transition metal site oxidation occurring at a lower potential. The transition metal site oxidation can be considered as the catalyst activation step which initiates the glucose oxidation. Transition metal doping at the active site also helped to redistribute the electron density thereby influencing catalyst activation and subsequent glucose oxidation steps. Interestingly, using highly occupied d-orbitals, slowed the electrocatalytic process. In this presentation we will discuss in details these structure property correlation and other factors influencing the electrocatalytic activity. We will also discuss how nanostructuring of the electrocatalysts on the other hand, increases the catalytic efficiency manifold by increasing the functional surface area for catalytic activity. Electrochemical measurements as well catalyst synthesis and processing will be discussed in details in this presentation.