Preparation Of Amino Acid Ionic Liquid And Its Application In The Construction Of Glucose Electrochemical Sensor

Electrochemical glucose sensor had the advantages of fast detection,accuration,low cost and portable funciton.The electrode material directly affected the analytical performance of the electrochemical glucose sensor.Ionic liquid had unique physicochemical properties,which attracted much attention in the preparation,modification and morphology regulation of electrode nanomaterials,but the biocompatible and environmentally friendly amino acid ionic liquids were more interesting to researchers.Based on the unique physical and chemical properties of amino acid ionic liquids and its potential application in the preparation of nanomaterials,the electrode materials of electrochemical glucose sensor were prepared by amino acid ionic liquids.This thesis studied the application of imidazole amino acid ionic liquids in electrochemical glucose sensor:(1)Imidazole amino acid ionic liquid was directly used as the fixed carrier of glucose oxidase(GOx)to construct the electrochemical glucose sensor;(2)Using imidazole amino acid ionic liquid as a new reducing agent and morphology regulator,metal and transition metal nano electrode materials were prepared by simple chemical precipitation method and hydrothermal method at room temperature to fabricate electrochemical glucose non-enzymatic sensor.(3)The analytical performance of glucose electrochemical sensor was investigated.The research mainly included the following contents:(1)Preparation and quantum chemical calculation of imidazole amino acid ionic liquidsTwenty-eight kinds of 1-methyl-3-n-alkyl imidazole amino acid ionic liquids[Cnmim]AA(n=4,6,8,12)were prepared by ion exchange resin method and characterized.By quantum chemistry calculation,the stability and reactivity of[Cnmim]AA(n=4,8,12)ionic liquids were analyzed from the molecular electrostatic surface potential(ESP)and the energy gap between the HOMO and LOMO(ΔE(HOMO-LUMO)).The results showed that the active site of[Cnmim]AA nucleophilic reaction was mainly located on the carboxylic acid anion of amino acid anion,and the active site of electrophilic reaction was mainly located on the imidazole cation.The energy gap ΔE(HOMO-LUMO)of 1-methyl-3-n-alkyl imidazolium Proline([Cnmim]Pro(n=4,8.12)was lower than that of other imidazolium amino acid ionic liquids.indicating that its charge transition was easy,so the higher the molecular reactivity,the lower the dynamic stability.(2)Electrochemical glucose sensor immobilized enzyme using[C12mim]Asp ionic liquid as carrier1-methyl-3-n-dodecyl imidazole aspartate ionic liquid([C12mim]Asp)was used as the fixed carrier of GOx to construct electrochemical glucose sensor.The results of surface tension,cryo-transmission electron microscopy and UV-vis spectroscopy showed that[C12mim]Asp ionic liquid had the characteristics of surfactant.The microenvironment formed by micelles and vesicles could maintain the bioactivity of GOx,and the direct electrochemical reaction of GOx was successfully achieved.The electrochemical glucose sensor showed good analytical performance,with a linear range of 1.00×10-3-0.58 mM and 0.58-12.00 mM,a detection limit(S/N=3)of 0.057μM and a sensitivity of 38.35 mA M-1 cm-2.In addition,the sensor showed good anti-interference and could be used to detect glucose in serum samples.This work provided a new fixed carrier for enzyme fixation and could be used to develop enzyme electrochemical sensors with excellent performance.(3)Preparation of gold nanomaterials with[C6mim]His ionic liquid and study on enzyme-free electrochemical glucose sensorA stable gold gel([C6mim]His@Au)was obtained by reducing chloroauric acid(HAuCl4)precursor with 1-methyl-3-hexanyl imidazole histidine ionic liquid([C6mim]His)as reducing agent and stabilizing agent at room temperature,replacing reducing agent sodium borohydride and surfactant hexanyl trimethyl ammonium bromide.After Fourier infrared spectroscopy(FT-IR),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS)characterization.A protective layer of[C6mim]His was formed on the surface of Au to prevent the agglomeration of Au nanoparticles.An enzyme-free electrochemical glucose sensor with[C6mim]His@Au modified electrode was constructed.The sensor showed good analytical performance with a linear range of 1.0-8.0 mM and 8.0-24.0 mM,the detection limit(S/N=3)of 0.67 μM and the sensitivity of 64.89 mA M-1 cm-2.In addition,the sensor had good anti-interference ability and could be used to detect glucose in serum samples.This work provided a new,simple and rapid method to prepare gold gel,and provided a new strategy for electrode modification of enzyme-free electrochemical sensors.(4)Preparation of flower-like nickel-based nanomaterials self-assembly with[C4mim]Pro ionic liquid and study on enzyme-free electrochemical glucose sensor1-methyl-3-n-alkyl imidazole-proline ionic liquids([Cnmim]Pro(n=4,8,12))were used as reducing agents and morphology regulators to realize morphology control of nickel-based nanomaterials,morphology control conditions were optimized,and flower-like Ni nanomaterials were obtained by hydrothermal self-assembly.The flower-like nanomaterial(Ni/NiO/Ni(OH)2 complex)was characterized by FT-IR,X-ray diffraction(XRD)and XPS,and the surface of Ni-based nanomaterial was modified successfully by[C4mim]Pro ionic liquid([C4mim]Pro@Ni/NiO/Ni(OH)2).[C4mim]Pro@Ni/NiO/Ni(OH)2 had a large specific surface area,which was conducive to the efficient catalytic reaction of glucose.A enzyme-free electrochemical glucose sensor with[C4mim]Pro@Ni/NiO/Ni(OH)2 as the modified electrode was constructed.The linear ranges of the sensor were 0.2-1.0 mM and 1.0-12.2 mM,the sensitivity was 42.29 mA M-1 cm-2.The detection limit(S/N=3)was 0.24 pM.In addition,the enzyme-free electrochemical glucose sensor constructed by[C4mim]Pro@Ni/NiO/Ni(OH)2 had good anti-interference ability and could be used for the detection of glucose in serum samples.This work provided a new method for the regulation and synthesis of Ni-based nanomaterials.(5)Preparation of rambutan-like cobalt-based nanomaterials self-assembly with[C4mim]Pro ionic liquid and study on enzyme-free electrochemical glucose sensor[Cnmim]Pro(n=4,8,12)were used as the REDOX agent and morphology regulator to realize the morphology control of Co-based nanomaterials,the morphology control conditions were optimized,and rambutan-like Co based nanomaterials were obtained by hydrothermal self-assembly.After FT-IR,XRD and XPS characterization,the rambutan-like nanomaterial was CoO/Co3O4/CO(OH)2 complex,and the Co-based nanomaterial was successfully modified by[C4mim]Pro.A enzyme-free electrochemical glucose sensor with rambutard-like nanomaterial[C4mim]Pro@CoO/Co304/Co(OH)2 modified electrode was constructed.The linear range of the sensor was 0.001-1.0 mM and 1.0-6.0 mM,and the sensitivity was 37.53 mA M-1 cm-2.The detection limit(S/N=3)was 0.44 μM.In addition,[C4mim]Pro@CoO/Co3O4/Co(OH)2 constructed enzyme-free electrochemical glucose sensor had good anti-interference ability and could be used for the detection of glucose in serum samples.This work provided a new idea for the preparation and morphology regulation of Co-based nanomaterials.(6)Preparation of manganese-based nanomaterials with[C4mim]Pro ionic liquid and study on enzyme-free electrochemical glucose sensor[Cnmim]Pro(n=4,8,12)was used as the oxidant and morphology regulator,the morphology control conditions were optimized and the morphology control of Mn-based nanomaterials were realized.Mn-based nanomaterials were obtained at room temperature.The Mn-based nanomaterial was characterized by FT-IR,XRD,XPS and other means,and the surface of MnO2 nanomaterial was successfully modified by[C4mim]Pro([C4mim]Pro@MnO2).A enzyme-free electrochemical glucose sensor with spherical nanomaterial[C4mim]Pro@MnO2 modified electrode was constructed.The linear range of the sensor was 1.0-2.0 mM and 2.0-5.8 mM,the sensitivity was 34.65 mA M-1 cm-2,and the detection limit(S/N=3)was 13.29 μM.In addition,the enzyme-free electrochemical glucose sensor constructed by[C4mim]Pro@MnO2 had good anti-interference ability and had been successfully used to detect glucose in serum samples.This work provided a simple,rapid and mild method for the preparation of MnO2 nanomaterials.