HANOI UNIVERSITY OF SCIENCE AND TECHNOLOGY MASTER THESIS In situ growth of Ni(OH)2 nanostructures on substate for glucose measurement VU THI OANH Oanh.vn Major of Materials Science Supersivor: Dr. Chu Thi Xuan Signature of Supervisor Institute International Training Institute for Materials Science (ITIMS HANOI, 05/2022 SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom - Happiness CONFIRMATION OF MASTER’S THESIS ADJUSTMENT Full name of author: Vu Thi Oanh Thesis topic: In situ growth of Ni(OH)2 nanostructures on substate for glucose measurement Major: Materials Science Student ID: 20202682M The author, the supervisor, and the Committee confirmed that the author has adjusted and implemented the thesis according to the report of the Committee on May 19th, 2022 with the following contents: The thesis has been corrected for typographical errors and printing according to the opinions of the committee’s members. June 2nd 2022 Supervisor Author Dr. Chu Thi Xuan Vu Thi Oanh COMMITTEE’S CHAIRMAN Assoc.
Nguyen Van Quy THESIS TOPIC In situ growth of Ni(OH)2 nanostructures on substrate for glucose measurement Acknowledgement To complete this thesis, I would like to strongly express deep gratitude to my supervisor, Dr. Chu Thi Xuan, who directly instructed me as well as helped me write this thesis. I would like to sincerely thank all professors, lecturers, and employees at ITIMS for their kindness to support me during a period I have already studied and worked there. I sincerely thank my groupmates in Nanosensors Laboratory and many others who supported me in doing experiments and research.
They are my good mentors and good friends who I am really appreciated. I would like to thank “The Domestic Master/Ph. Scholarship Programme” of Vingroup Innovation Foundation (VINIF), Vingroup Big Data Institute (VINBIGDATA), code VINIF.33 for supporting my master's course. I also thank the project grant number B2022-BKA-25 CTVL.
Finally, I want to warmly thank my family who always encourages me to follow my research career. Master student (Sign and write full name) Vu Thi Oanh Abstract Glucose sensor has attracted the attention of academic and industrial researchers because of its broad applications in diabetes management, food quality control and bioprocess inspection. Compared with enzymatic glucose sensors, non-enzymatic glucose sensors are more relevant because of their stable, sensitive, and low-cost process. The simple and low-cost synthesis of advanced nanomaterials for non-enzymatic glucose sensor is vital in practical application.
Here, we introduce a facile chemical method for the synthesis of nickel(II) hydroxide nanostructures on porous nickel foam (NF) for electrochemical glucose sensor. The properties of the synthesized material were characterised by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, selected area electron diffraction, and Raman spectroscopy. The fabricated materials were applied for glucose concentration measurement in 0.1 M NaOH by cyclic voltammetry and chronoamperometry. The Ni(OH)2/NF sensor is stable and has excellent sensitivity with low detection limit based on the signal-to-noise ratio of 3 and high selectivity for glucose detection in the presence of common interfering species.
The Ni(OH)2/Ni electrode was successfully tested in measuring glucose concentration in real serum samples. The fabricated Ni(OH)2/NF electrode can be used as a low-cost, sensitive, stable and selective platform for non-enzymatic glucose sensor. TABLE OF CONTENTS INTRODUCTION .1 Overview of glucose, blood sugar, and diabetes mellitus .1 Introduction of biosensor .2 Introduction of electrochemical glucose sensor .3 Nickel(II) hydroxide nanostructures .1 Electrochemical behaviours of Ni(OH)2 toward glucose in alkaline….2 Structure and characteristics of Ni(OH)2 nanostructures .3 Methods to synthesis of Ni(OH)2 nanostructures. EXPERIMENTS AND METHODS .1 Chemical and apparatus .2 Ni(OH)2 nanostructures fabrication .3 Characterization of the morphologies and composition of the synthesized materials .1 Scanning Electron Microsope (SEM) .2 Transmission Electron Microscopy (TEM).
Characterization of electrochemical properties of the synthesized materials. RESULTS AND DISCUSSTION .1 Morphologies and structural characteristics of the synthesized materials33 3.1 FESEM images of the synthesized materials .2 HRTEM images of the synthesized materials .3 Components of the synthesized materials .2 Cyclic voltammetry measurement of the synthesized materials in alkaline medium. Influence of reaction time on the electrochemical properties of the synthesized materials. CV measurements toward glucose in alkaline medium.
Influence of scan rate. The stability and reproducibility. Chronoamperometry measurement of the synthesized materials in alkaline medium .1 Optimization of the statical potential applied .2 Construct the calibration curve for the determination of glucose concentration .4 The effect of interferences of Ni(OH)2/NF .5 Application of the synthesized electrode for glucose measurement in real samples .6 NiO nanohives based on Ni(OH)2-precursors for glucose measurement in alkaline .1 Formation of NiO from Ni(OH)2-precursors .2 Electrochemical behaviors and glucose measurements of the synthesized NiO. 54 LIST OF PUBLICATIONS.
55 PUBLICATIONS IN PROGRESS. Abbreviations and symbols Meaning 1 SEM Scanning Electron Microscope Field-emission scanning 2 FESEM electron microscopy Transition Electron 3 TEM Microscope High resolution transmission 4 HRTEM electron microscopy Selected area electron 5 SAED diffraction Energy-dispersive X-ray 6 EDS/EDX spectroscopy 7 CV Cyclic voltammetry 8 CA Chronoamperometry 9 NF Nickel foam 10 LOD Limit of detection 11 HMTA Hexamethylenetetramine 12 AA L-ascorbic acid 13 DA Dopamine 14 CA Citric acid monohydrate 15 DI Deionized water 16 RE Reference electrode 17 CE Counter electrode 18 WE Working electrode LIST OF TABLES Table 1.1: Unit cell parameters for the two fundamental phases of Ni(OH)2.2: X-ray diff raction parameters of β-Ni(OH)2. Diff raction angles are listed for Cu Kα (λ = 1.3: X-ray diff raction parameters of α-Ni(OH)2 calculated using the unit cell shown in figure 1. Diff raction angles are listed for Cu Kα (λ = 1.1: Comparison of the performance of the synthesized Ni(OH)2/NF and other nickel-based materials for non-enzymatic glucose sensors.2: Measurement of glucose concentration of real human blood serum samples.3: To compare the glucose electrochemical sensing of the fabricated sensors with other nickel-based sensors.
52 LIST OF FIGURES Figure 1.1: Structural chemical formulas of glucose (D-glucose) [25].2: Schematic representation of a biosensor [32].3: Schematic drawing of the first-generation glucose sensor [47].4: Schematic drawing of the second-generation glucose sensor [47].5: Schematic representation of a third-generation biosensor [47].6: A general scheme of the chemical and electrochemical processes that occur at a nickel hydroxide battery electrode.7: Mechanism of oxidation-reduction electrochemical reaction between Ni(OH)2 and glucose in alkaline medium.8: A non-enzymatic glucose sensor based on Ni(OH)2 nanoplatelet based on GCE and ECF [55].9: The crystal structure of β-Ni(OH)2 [57].10: The idealized crystal structure of α-Ni(OH)2 · xH2O [57].11: X-ray diff raction patterns of Ni(OH)2 films on Ni substrates collected using a Cu Kα X-ray source [57].12: Raman spectra of (a) β-Ni(OH)2, (b) α-Ni(OH)2 and (c) nitrate- intercalated α-Ni(OH)2 [57].13: Six methods to prepare Ni(OH)2 [57].14: Examples of Ni(OH)2 prepared by different methods [57].1: Images of the commercial nickel foam.2: Experiment procedure for fabrication of materials.4: Field-emission scanning electron microscopy (FESEM) with energy- dispersive X-ray spectroscopy (Hitachi S-4800).5: Classification of TEM [62].6: Working principle of TEM [62].7: Renishaw Invia Raman Microscope.9: a) Potential step, b) the decrease of concentration of electrochemical substance, c) relationship between current and time [63].10: Autolab electrochemical workstation (PGSTAT302N, Netherlands).11: Scheme for electrochemical measurement diagram.1: FESEM images of (a) the bare NF and (b-d) the Ni(OH)2/NF electrodes.2: Higher magnification of FESEM images of the Ni(OH)2/NF electrodes with different reaction time.5: CV curves of the bare NF, and the fabricated Ni(OH)2 with different reaction time working electrodes in 0.1 M NaOH with a potential range from -1.5 V at the scan rate of 10 mV/s.6: The change of current value in CV curve when adding 0.5 mM glucose into 0.1 mM NaOH of the fabricated Ni(OH)2 electrode with different reaction time .7: (a) CV curves of the Ni(OH)2/NF electrode at a scan rate of 10 mV/s in 0.1 M NaOH with glucose concentration from 0 to 6 mM, (b) plot of reduction peak currents versus glucose concentrations.8: (a) CV curves of the Ni(OH)2/NF electrode in 0.1 M NaOH and 1 mM glucose solution at different scan rates from 10 mV/s to 100 mV/s, (b) plot of reduction peak current to the square root of the scan rates.9: CV curves of (a) five different Ni(OH)2/NF working electrodes synthesized with the same condition, (b) the Ni(OH)2/NF working electrode after three months stored in room temperature.11: I – t curves of the Ni(OH)2/NF electrode at 0. Ag/AgCl in 0.1 M NaOH containing the glucose concentration range from 0 mM to 0.5 mM and b) The calibration plot of response current vs.12: Amperometric response for successive addition of 0.05 mM DA, 15 mM NaCl, and 0.1 mM glucose to the Ni(OH)2/NF electrode in 0.1 M NaOH at the potential of 0.13: EDS pattern of the synthesized NiO.14: (a) Low and (b) high magnification FE-SEM images of the synthesized NiO/NF electrode.15: CVs plots of the NF and three NiO/NF electrodes synthesized under the same conditions.16: CVs plots of NiO/NF electrode in 20 mL of 0.1 M NaOH and 0, 3, 4, 5, 6, 7 mM glucose.17: (a) Amperometric response of NiO/NF toward glucose with a concentration range between 0 and 0.5 mM, and (b) The plot of dependence between response current and glucose concentration at different potentials. 51 INTRODUCTION Diabetes mellitus, one of the leading causes of death worldwide [1], is a disease characterized by chronic high blood glucose levels due to insulin metabolism disorder. Regular clinical monitoring of blood glucose levels is necessary to reduce diabetes risk [2].
Continuous studies have been focused on the development of highly sensitive, reliable, and rapidly responsive glucose sensors [2][3]. Two general pathways have been used in the development of glucose sensors, namely, traditional enzyme-based and non-enzymatic methods [4][5]. Enzymatic glucose sensors have outstanding selectivity and high sensitivity and are widely used for measuring glucose concentration [6][7]. However, these electrodes have some disadvantages, particularly the instability of specific enzymes on the surface of electrodes with pH, temperature, humidity, and ionic detergents [8–10].
Non-enzymatic biosensors have been developed to surmount the weaknesses of enzyme-based sensors [11][12]. Non-enzymatic glucose electrochemical sensor, in which the nanostructures of materials cover the electrode’s surface, has also attracted much attention because of its low cost, high stability, and low detection limit [13]. Transition metals (Cu, Co, Ni, etc.) and their oxides (Cu2O, CuO, NiO, Co3O4, etc.) have been introduced as selective and stable non-enzymatic glucose sensors owing to their excellent catalytic ability [14][15]. Amongst these materials, Ni-based nanostructures are considered an excellent electrocatalyst for glucose detection in alkaline media through Ni(OH)2/NiOOH redox couple [16][17].
Many methods have been used to synthesize nickel(II) hydroxide, such as chemical precipitation [19], sol–gel synthesis [20], and hydrothermal and solvothermal syntheses [21]. In these methods, Ni(OH)2 powders are synthesized and immobilized on an electrode with a binder [22]. Extra binders may have certain drawbacks, such as increased electrode mass, reduced cycle time and charge transport rates, and material denaturation, all of which might impact sensor signal [23]. The growth of Ni(OH)2 directly onto a conducting substrate is posible by electrochemical deposition, however this process requires expensive electrochemical equipment [24].
Furthermore, because sensor electrodes require an electrical connection to deposit materials onto the sensing region, large-scale production of the biosensor by electrochemical deposition is constrained. For the creation of a stable electrochemical sensor, a method for the instant in situ deposition of Ni(OH)2 nanostructures on a porous substrate, such as nickel foam (NF), is required. The wide surface area of sensing materials put on the porous substrate is also critical for the sensor's performance. 1 The aim of the thesis is to “Fabrication of Ni(OH)2 nanostructures directly on the nickel foam electrode by a simple, rapid and low-cost chemical method to apply for non-enzymatic glucose sensor”.
Objectives of this thesis are: (1) Directly synthesis of Ni(OH)2 nanostructures on the nickel foam electrode via a instant facilite process; (2) Investigation of the physical-chemical properties of the synthesized materials; (3) Investigation of the electrochemical behaviours of the synthesized Ni(OH)2 toward glucose in alkaline solution.1 Overview of glucose, blood sugar, and diabetes mellitus Glucose (molecule formula: C6H12O6, IUPAC name: (2R,3S,4R,5R)- 2,3,4,5,6 pentahydroxylhexanal) is the most common monosaccharide. Glucose has two kinds of rings, α-D-Glucose and β-D-Glucose which are the main energy source of cells in the body.