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US-12618793-B2 - Molybdenum oxide and cobalt oxyhydroxide composite electrochemical glucose sensor

US12618793B2US 12618793 B2US12618793 B2US 12618793B2US-12618793-B2

Abstract

A composite is provided which comprises planar molybdenum oxide microstructures and cobalt oxyhydroxide microstructures disposed on the planar molybdenum oxide microstructures. A method of forming the composite is also provided. The composite is used in the fabrication of an electrochemical sensor, which comprises the composite, an electrode, and a polymeric coating. The electrochemical sensor is used in a method of detecting the presence of glucose in an analyte. The method involves applying a voltage to the electrochemical sensor relative to a counter electrode and measuring a current response. The method in insensitive to common oxidative interfering analytes such as urea, lactate, and NaCl.

Inventors

  • Tahani ALFAREED
  • Jwaher M. Alghamdi
  • Emre CEVIK

Assignees

  • IMAM ABDULRAHMAN BIN FAISAL UNIVERSITY

Dates

Publication Date
20260505
Application Date
20221130

Claims (20)

  1. 1 . A composite, comprising: planar molybdenum oxide microstructures having a mean thickness of 0.5 to 5 μm and a mean width of 1 to 10 μm; and cobalt oxyhydroxide microstructures having a mean size of 1 to 8 μm disposed on a surface of the planar molybdenum oxide microstructures, wherein the molybdenum oxide is crystalline by PXRD and the cobalt oxyhydroxide is crystalline by PXRD.
  2. 2 . The composite of claim 1 , wherein the molybdenum oxide is α-MoO 3 .
  3. 3 . The composite of claim 1 , which is substantially free of a metal hydroxide material by PXRD.
  4. 4 . The composite of claim 1 , which is substantially free of a carbon nanomaterial.
  5. 5 . A method of forming the composite of claim 1 , the method comprising: mixing a molybdenum source and an aminotriazole to form a first intermediate; calcining the first intermediate at 500 to 900° C. for 1 to 12 hours to form planar molybdenum oxide microstructures; treating the planar molybdenum oxide microstructures with an acid to form activated microstructures; mixing the activated microstructures, a cobalt ion source, and water to form a reaction mixture; and hydrothermally treating the reaction mixture at 175 to 245° C. for 12 to 96 hours to form the composite.
  6. 6 . The method of claim 5 , wherein the molybdenum source is ammonium molybdate.
  7. 7 . The method of claim 5 , wherein the aminotriazole is 3-amino-1H,2,4-triazole.
  8. 8 . The method of claim 5 , wherein the cobalt ion source is cobalt (II) nitrate.
  9. 9 . An electrochemical sensor, comprising: an electrode; the composite of claim 1 disposed on the electrode; and a polymeric coating disposed on the composite.
  10. 10 . The electrochemical sensor of claim 9 , which is substantially free of an enzyme.
  11. 11 . The electrochemical sensor of claim 9 , wherein: the electrode is a glassy carbon electrode; and the polymeric coating is Nafion.
  12. 12 . The electrochemical sensor of claim 9 , having an anodic peak centered at greater than 0.2 to 0.28 V and a cathodic peak centered at 0.15 to 0.2 V as measured vs Ag/AgCl in 0.1 M NaOH.
  13. 13 . A method of detecting the presence of glucose in an analyte, the method comprising: immersing a working electrode comprising the electrochemical sensor of claim 9 , a reference electrode, and a counter electrode in an analyte comprising a dilute hydroxide base; applying a voltage to the working electrode and counter electrode; measuring a current response to determine at least one selected from a cathodic peak voltage, an anodic peak voltage, and a steady-state current; and determining the presence of glucose in the analyte based on at least one selected from the group consisting of the cathodic peak voltage, the anodic peak voltage, and the steady-state current.
  14. 14 . The method of claim 13 , wherein the voltage is applied in a range of 0.01 to 0.5 V.
  15. 15 . The method of claim 13 , wherein the dilute hydroxide base is 0.1 M NaOH.
  16. 16 . The method of claim 13 , wherein the analyte has a pH of 8 to 14.
  17. 17 . The method of claim 13 , wherein the reference electrode is an Ag/AgCl electrode.
  18. 18 . The method of claim 13 , having a glucose detection limit of 10 to 100 μM.
  19. 19 . The method of claim 13 , having a glucose sensitivity of 4 to 8 μA mM −1 cm −2 .
  20. 20 . The method of claim 13 , having a linear amperometric current response in a glucose concentration range of 0.001 to 5.0 mM.

Description

BACKGROUND OF THE INVENTION Field of the Invention The present disclosure relates to a composite which includes planar molybdenum oxide microstructures and cobalt oxyhydroxide microstructures, a method of forming the composite, an electrochemical sensor which includes the composite, and a method of detecting glucose in an analyte using the electrochemical sensor. Discussion of the Background The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present invention. The glucose sensor is a critical tool in fields such as biotechnology, clinical healthcare, and food analysis. Glucose sensors have allowed reliable, rapid glucose sensing with high sensitivity [Lamiri, L., et. al., Synthetic Metals, 2020, 266, 116437]. Several sensing paradigms have been used to fabricate glucose sensors. Electrochemical sensing is one of the most convenient and effective glucose sensing techniques, in part due to low cost, high sensitivity, fast response time, and easy operation [Manafi-Yeldaghermani, R., et. al., Microchemical Journal, 2021, 169, 106636; and Emir, G., et. al., Microchemical Journal, 2021, 161, 105751]. Of electrochemical sensors, enzymatic modified sensors are by far the most studied. However, there are difficulties and drawbacks related to the use of enzymes in glucose sensing. Importantly, enzymatic sensors exhibit poor stability from the inherent fragility of enzymes, costly and stringent storage conditions (e.g., pH, temperature, humidity), challenging enzyme immobilization processes during fabrication, and high costs [Savk, A. et. al., Journal of Molecular Liquids, 2020, 300, 112355; and Abbasi, A. R., et. al., Journal of Inorganic and Organometallic Polymers and Materials, 2020, 30, 2027-2038]. Factors to consider in the preparation of practical non-enzymatic glucose sensors include the use of materials which are inexpensive, selective, stable, and biocompatible [Wang, F., et. al., Polymers, 2020, 12, 10, 2419]. Examples of such materials include transition metals and metal oxides and hydroxides, polymers, and carbon nanomaterial [Mo, G., et. al., Talanta, 2021, 225, 121954; Wei, H., et. al., Sensors and Actuators B: Chemical, 2021, 337, 129687; Zhao, Z., et. al., Sensors and Actuators B: Chemical, 2021, 326, 128811; Zhang, Y., et. al., Sensors and Actuators B: Chemical, 2020, 309, 127779; and Jeong, H., et. al., Materials Science and Engineering C, 2021, 118, 111510]. Among various metal compounds, the nanostructured metal oxides have recently noticed in biosensor development due to their remarkable advantages in the factors described above [Karthika, A., et. al., Microchemical Journal, 2019, 145, 737-744; and Karthika, A., et. al., Ultrasonics Sonochemistry, 2019, 55, 196-206]. One of the most promising transition metal oxides for use in electrochemical sensors is molybdenum trioxide (MoO3) owing to the distinctive chemical properties such as chemical and thermal stability, band gap energy of 2.39-2.9 eV, and multiple accessible oxidation states [Ramana, C. V., and Julien, C. M., Chemical Physics Letters 2006, 428, 1-3, 114-118; and Zhao, D., et. al., Materials Letters, 2019, 256, 126648]. MoO3 has been used in applications including smart windows, optical devices, electrochemical storage, sensors, and catalysis [Mai, L. Q., et. al., Microelectronic Engineering, 2003, 66, 1-4, 199-205]. However, MoO3 has disadvantages in electrochemical sensing including low sensitivity, high oxidation potential, facile aggregation, fouling, and decreases in electrocatalytic activity [Mohamed Azharudeen, A., et. al., Microchemical Journal, 2020, 157, 105006]. One approach to overcoming limitations in a single material is to prepare hybrid materials, which can combine advantages from different components to cover the disadvantages in certain materials. For example, Lee, et. al. prepared an electrochemical glucose sensor from the combination of an Au—Ni alloy and a conductive polymer. [Lee, W. C., et. al., Biosensor and Bioelectronics, 2019, 130, 48-54]. Khalaf, et. al. prepared an electrochemical glucose sensor from silver nanoparticles and chitosan [Khalaf, et. al., International Journal of Biological Macromolecules, 2020, 146, 763-772]. Jo, et. al. prepared a glucose sensor based on Ni—Co mixed oxide nanoneedles decorated with polymer dots [Jo, et. al., Journal of Industrial and Engineering Chemistry, 2020, 89, 25, 485-493]. Gao, et. al. prepared an electrochemical glucose sensor from a combination of molybdenum disulfide and copper sulfide coated with poly(vinyl butyral) [Gao, Z. et. al., Microchimica Acta, 2017, 184, 807-814]. Li, et. al. prepared “cobalt-functionalized MoS2” and carbon