Dissertation > Excellent graduate degree dissertation topics show

Fabrications and Applications of Microelectrode Array of Silicon Dioxide Cavities and Magnetic Ferroferric Oxide Nano-Bioconjunctions

Author: ZhouLiJuan
Tutor: YinFan
School: Suzhou University
Course: Drug analysis
Keywords: sol-gel technique solvothermal method silicon dioxide cavities ferroferric oxide magnetic nanoparticles hemoglobin myoglobin horseradish peroxidase
CLC: TB383.1
Type: Master's thesis
Year: 2011
Downloads: 17
Quote: 0
Read: Download Dissertation

Abstract


Microelectrode possessed of unexpected advantages comparing with a normal electrode, such as small capacitive-charging currents, reduced iR drop and steady-state diffusion currents, but single microelectrode has low current response normally, microelectrode array （MEA） which is an assembly of microelectrodes in ordered manner can resolve the problem. MEA can not only enlarge the current response but also keep the electrochemical properties of single microelectrode. So, it can get better satisfied results than normal electrochemical instruments. Magnetic nanoparticles （MNPs） are a kind of novel material which have recently received more attentions due to their potential applications in many fields because of their unique chemical and physical properties. The two materials both have good potentials in the field of biosensor. Here, we prepared silicon dioxide （SiO2） cavities array, nano-Au/SiO2 cavities array and magnetic ferroferric oxide （Fe3O4） nano-bioconjunctions through easy methods. The electrochemical applications of the obtained materials were investigated. The main results are summarized as follows:1 Preparations of SiO2 cavities array and magnetic Fe3O4 nano- bioconjunctions1.1 A SiO2 cavities microelectrode array was fabricated on indium-tin oxide （ITO） electrode surface with the template of the polystyrene（PS） particles array by using sol-gel technique. Nano-Au modified SiO2 cavities microelectrode array was constructed by electrodepositing nano-Au particles at the inside of SiO2 cavities. The properties of obtained microelectrode array were studied by automatic microscopy, scan electron microscopy （SEM） and cyclic voltammogram （CV） method.1.2 we presented a facile and low-cost route to prepare monodisperse Fe3O4 magnetic nanoparticles （MNPs ） by solvothermal method. Uniform Fe3O4MNPs were coated with silica layer through a sol-gel approach to obtain nonporous SiO2/Fe3O4MNPs. The morphology and magnetic property of SiO2/Fe3O4MNPs were characterized by transmission electron microscopy （TEM） and magnetic hysteresis loops.2 Bio-electrochemical applications2.1 hemoglobin（Hb） and myoglobin （Mb） were immobilized on the SiO2 microelectrode array and nano-Au/SiO2 microelectrode array using dipping method, respectively. Direct electrochemistries of the two enzymes were studied. Hb and Mb could keep great activities on the obtained microelectrode array. The results indicated that the two biosensors provided excellent responses for H2O2. The linear relationships between current response and the concentration of H2O2 ranged from 2.03×10-6～1.21×10-2 mol/L and 7.31×10-6～6.90×10-3 mol/L, detection limits were 5.73×10-7 mol/L and 9.99×10-7mol/L, the apparent Michaelis-Menten constants （KMapp） were 0.266mmol/L and 1.92mmol/L, respectively. The results showed that the immobilized enzymes had high activities and great compatible ability with H2O2.2.2 SiO2/Fe3O4MNPs which were treated with the mixed solution of poly（diallyldimethylammonium chloride） （PDDA） and sodium chloride （NaCl） was mixed with Hb and horseradish peroxidase （HRP）,respectively. Then two mixtures were dropped on the surface of ITO respectively to fabricate biosensors. Direct electrochemistries of the two proteins were studied. The two modified electrodes have rapid responses to H2O2 with wide linear ranges from 2.03×10-6～4.05×10-3 mol/L and 9.15×10-6～4.11×10-2mol/L, detection limits were 3.70×10-7mol/L and 1.67×10-6mol/L, KMapp were 1.74mmol/L and 1.79mmol/L, respectively. The results showed that the enzymes which were modified the surface of SiO2/Fe3O4MNPs could keep great activities and had good compatible abilities with H2O2.

Related Dissertations

  1. Of Bi N Co-doped TiO \u003csub\u003e 2 \u003c/ sub\u003e of the preparation and performance,O614.411
  2. Study on Mixed Strain for Liquid State Fermentation of Animal Blood,S816.4
  3. Efficacy and Safety of Biphasic Insulin Aspart 30 Once-daily Treatment in Patients with Type 2 Diabetes,R587.1
  4. Study on Clinical Value of High-sensitivity Cardiac Troponin T Assay in Myocardial Infarction,R542.22
  5. Clinical Therapeutic Effect and Safety of Insulin Determir in Type 2 Diabetes Patients,R587.1
  6. High-frequency Ultrasound in Evaluation on Impact of Glycosylated Hemoglobin to Carotid Intima-medial Thickness and Remodeling of Carotid Atherosclerosis for Type 2 Diabetes Mellitus Patients,R445.1
  7. Application of Photoacoustic Microscopy in Cerebral Hypoperfusion Model of Rats,R743.3
  8. Prognostic Value of Hemogologbin Alc in Patients with Acute Coronary Syndrome,R541.4
  9. Study on Perfluorohexylation and Perfluorobutylation of [60]Fullerene,O613.71
  10. A Study of Inspection Methods of Vascular Endothelial Growth Factor (VEGF) in Peripheral Venous Blood of Patients with Breast Cancer,R737.9
  11. The Effect of HAART on the Blood Routine Examination of AIDS Patients,R512.91
  12. Catalytic Fluorescence, Scattering Method for the Determination of Hemoglobin, Copper(Ⅱ) and Hydrogen Peroxide,R446.1
  13. Preparation of Zirconia Composite Ultrafiltration Membranes and Application in Seawater Desalination Pretreatment,P747
  14. Controlled Synthesis, Characterization and Performce of Ceria or Yttria Micro/Nanostructures,TB383.1
  15. Construction of Tryptophan Overproducing E.coli Strain,TQ922.9
  16. Biochemical Fundamental of Enzyme Sensor and Quantization Immunity Index,TP212.3
  17. Effects of Improve Insulin Resistance on the Level of Serum Glucagon-like Peptide-1 in Type 2 Diabetic Patients,R587.1
  18. Impact of Computer Radiation on a Part of Tissue Morphologically of Mice,R361.2
  19. Studies on Flow Injection-Chemiluminescence Detection and Its Applications,O657.3
  20. The Correlation of Tongue with Fasting Blood Glucose in Type 2 Diabetes Qi and Yin Deficiency and Blood Stasis Block Syndrome before and after Treatment,R259

CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Special structural materials
© 2012 www.DissertationTopic.Net  Mobile