Design and Fabrication of Glucose Biosensors Based on Immobilization of Glucose Oxidase on Titanium Oxide Nanotube Arrays

An electrochemical biosensor for the detection of glucose is realized by immobilizing glucose oxidase (GOx) enzyme onto titanium dioxide nanotube arrays by a coupling encapsulation process. We present details of a robust fabrication technique that results in a durable and reproducible sensor characteristics. The TiO2 nanotube arrays are grown directly on a titanium substrate by a potentiostatic anodization process in a water and ethylene-glycol mixture solution, which contains ammonium fluoride. An electropolymerization process was also performed to enhance interfacial adhesion between GOx and TiO2 nanotubes. Detection of glucose concentrations was achieved with a linear response in the range of 0.01 to 0.2 mM. Investigation of enhanced sensitivity by increasing the count, the length, and the cross-section of the nanotubes was also carried out. Surface morphologies of Ti substrate were examined by scanning electron microscopy to optimize the anodization process and thus the TiO2/Ti nanotube dimensions. We utilized a time-based amperometric response for the quantitative determination of hydrogen peroxide concentration through electro-reduction reaction with a bare TiO2/Ti nanotube-array electrodes, thus providing a reference for the determination of glucose levels with a GOx-coated TiO2/Ti nanotube array electrodes. Detection levels down to 5.2 μM were recorded.

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Photoelectrochemical Properties of Highly-ordered Titania Nanotube-arrays

MRS Proceedings ◽

10.1557/proc-837-n3.13 ◽

2004 ◽

Vol 837 ◽

Author(s):

Maggie Paulose ◽

Oomman K. Varghese ◽

Karthik Shankar ◽

Gopal K. Mor ◽

Craig A. Grimes

Keyword(s):

Charge Separation ◽

Nanotube Arrays ◽

Nanotube Array ◽

Precise Control ◽

Array Architecture ◽

Titania Nanotube Arrays ◽

Anodization Process ◽

Titania Nanotube ◽

20 Nm ◽

Water Photoelectrolysis

ABSTRACTWe report on non-particulate titania photoelectrodes with a unique highly-ordered nanotube-array architecture prepared by an anodization process that enables precise control over array dimensions. Under 320–400 nm illumination titania nanotube-array photoanodes, pore size 110 nm, wall thickness 20 nm, and 6 μm length, generate hydrogen by water photoelectrolysis at a normalized rate of 80 mL/W•hr, to date the most efficient titania-based photoelectrochemical device, with a conversion efficiency of 12.25%. The highly-ordered nanotubular architecture allows for superior charge separation and charge transport, with a calculated quantum efficiency of nearly 100% for incident photons with energies larger than the titania bandgap.

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Preparation and Microstructure of Titania (TiO2) Nanotube Arrays by Anodization Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.802.104 ◽

2013 ◽

Vol 802 ◽

pp. 104-108 ◽

Cited By ~ 4

Author(s):

Buagun Samran ◽

Pacharee Krongkitsiri ◽

Saichol Pimmongkol ◽

Sopon Budngam ◽

Udom Tipparach

Keyword(s):

Ammonium Fluoride ◽

Deionized Water ◽

Nanotube Arrays ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Dc Power ◽

Atomic Force ◽

Anodization Process ◽

Anodization Method

TiO2 nanotube arrays were successfully synthesized by the anodization method of Ti foils in electrolyte containing the mixtures of ethylene glycol (EG), ammonium fluoride (0.3 wt % NH4F) and deionized water (2 Vol % H2O). A constant dc power supply at 50 V was used anodization process with different anodizing times. The resultant samples were annealed at 450 °C for 2 h. TiO2 nanotube arrays were studied by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The prepared TiO2 NTs has diameter in 50-200 nm. The minimum of diameter TiO2 nanotube arrays was approximately 50 nm for 1 h of anodization process.

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Synthesis of Self-Aligned Titanium Oxide Nanotube Arrays in Ammonium Fluoride-Ethylene Glycol Electrolytes with Different Water Contents

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.463-464.788 ◽

2012 ◽

Vol 463-464 ◽

pp. 788-792

Author(s):

Sasitorn Thongyoy ◽

Areeya Aeimbhu

Keyword(s):

Electron Microscopy ◽

Ethylene Glycol ◽

Room Temperature ◽

Titanium Substrate ◽

Ammonium Fluoride ◽

Nanotube Arrays ◽

Water Based ◽

Water Contents ◽

Anodisation Process ◽

Scanning Electron

The aim of this research is to fabricate of TiO2nanotube arrays by potentiostatic anodisation process on titanium sheets. Anodisation is carried out under various applied potentials ranging from 20 to 30 volts for 1-3 hours at room temperature. Anodised were conducted in 1-4 wt% NH4F, water-based electrolyte and ethylene glycol-based electrolyte. The morphology of the anodised surfaces were characterised by scanning electron microscopy. When titanium sheets were anodised in various conditions, surface morphology of anodised titanium change remarkably with the changing of applied voltages, chemical composition of the electrolyte and anodisation time. The results of the present work show that the highly ordered and uniformly distributed TiO2nanotubes on titanium substrate can be fabricated by using mixtures of NH4F, ethylene glycol and water with appropriate conditions. Moreover, the anodisation potential and the water content play significant roles in the formation of TiO2nanotube with different inner tube diameters. The length of TiO2nanotube was controlled by anodisation time.

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A New and Rapid Method for the Determination of Glucose by Measurement of Rate of Oxygen Consumption

Clinical Chemistry ◽

10.1093/clinchem/14.2.116 ◽

1968 ◽

Vol 14 (2) ◽

pp. 116-131 ◽

Cited By ~ 463

Author(s):

Arnold Henry Kadish ◽

Robert L Litle ◽

James C Sternberg

Keyword(s):

Hydrogen Peroxide ◽

Oxygen Consumption ◽

Glucose Oxidase ◽

Oxygen Sensor ◽

Direct Measure ◽

Peroxide Formation ◽

Glucose Levels ◽

Rate Of Oxygen Consumption ◽

Hydrogen Peroxide Formation

Abstract Glucose levels in serum, plasma, and urine are determined rapidly and conveniently by a new glucose oxidase method employing a polarographic oxygen sensor with a circuit modified to record the rate of oxygen consumption. The maximum apparent rate of oxygen consumption relative to the rate obtained with a glucose standard provides a direct measure of the glucose level in the sample; results are obtainable within 20 sec. after sample (100 µl.) addition and within 3 min. after a blood sample is withdrawn from a patient. Interferences associated with prior colorimetric glucose oxidase methods are avoided by measuring oxygen consumption instead of hydrogen peroxide formation. The method is described and results are presented showing a standard deviation of less than 1.5% on replicate determinations and a bias of 1% with respect to data obtained on the same samples by the automated ferricyanide method.

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Bestimmung der Glukosekonzentration im Venenblut mit verschiedenen Glukometern zur Blutzuckerselbstkontrolle im Vergleich zur Glukoseoxidase (GOD)-Methode am ESAT 6660-2/ECA 2000. Determination of Glucose Levels in Venous Blood by the Use of Various Glucometers for Glucose Self Monitoring Compared to the Glucose-Oxidase-Method on the ESAT 6660-2/ECA 2000

LaboratoriumsMedizin ◽

10.1515/labm.2000.24.9.397 ◽

2000 ◽

Vol 24 (9) ◽

pp. 397-406

Author(s):

H.-G. Lestin ◽

M. Augsten ◽

F. Lestin ◽

M. Hergert ◽

G. Winkler ◽

...

Keyword(s):

Glucose Oxidase ◽

Venous Blood ◽

Self Monitoring ◽

Glucose Levels

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Study on Fabrication and UV Photoelectric Property of TiO2 Nanotube Array Electrodes

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2016.11830 ◽

2016 ◽

Vol 16 (4) ◽

pp. 3945-3950

Author(s):

Fu Yao ◽

Duan Xiao-Long ◽

Xing Ming-Ming ◽

Luo Xi-Xian ◽

Zhang Ying-Hui ◽

...

Keyword(s):

Oxide Layer ◽

Photoelectric Property ◽

Defect Density ◽

Tube Wall ◽

Anatase Phase ◽

Ammonium Fluoride ◽

Tube Length ◽

Nanotube Arrays ◽

Nanotube Array ◽

Photoelectric Properties

Highly ordered TiO2 nanotube array electrodes were successfully fabricated by a two-step anodization method on Ti sheet substrates in an electrolyte composed of ammonium fluoride, deionized water, and glycol. The tube wall was smooth, and the average internal and external diameters, wall thickness, and tube length achieved were 80 nm, 90 nm, 10 nm, and 9 μm, respectively. X-ray diffraction and field emission scanning electron microscopy results revealed that the TiO2 nanotube arrays presented an amorphous structure. When calcined at 300 °C, the arrays crystallized into the anatase phase, and the crystallization degree of the oxide layer increased as the temperature rose. Calcinating at 400 °C did not obviously disrupt the porous structure of the highly ordered arrays. However, higher temperature enlarged the diameter of the nanotube array and roughened the tube wall. When the temperature reached 600 °C, the nanotube mouth broke because of the excessive stress, causing the oxide layer’s thinness and nanotube mouth clogging. The photoelectric test showed that the electrode presented obvious photoresponse under 300–400 nm UV excitation (maximized at 360 nm). The degree of crystallization and the micro-structure of the oxide layer can significantly affect the photoelectric properties of the electrode. After calcination at 400 °C, the TiO2 nanotube arrays, with highly ordered tubular structure directly connected to the Ti substrate, can ensure the rapid transportation of photo-induced electrons to the Ti substrate, while the high crystallinity of the arrays can help reduce the defect density of the nanotube and extend the lifetime of the photo-induced carriers. The electrode showed the best photoelectric property, and the photocurrent intensity was maximized (29.6 μA). However, the calcination process with over-temperature resulted in substantial loss of the TiO2 oxide layer, mouth clogging, and a severe decline in the photoelectric properties.

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Single Step Formation of C-TiO2Nanotubes: Influence of Applied Voltage and Their Photocatalytic Activity under Solar Illumination

International Journal of Photoenergy ◽

10.1155/2013/276504 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Chin Wei Lai ◽

Srimala Sreekantan

Keyword(s):

Photocatalytic Activity ◽

Applied Voltage ◽

Active Surface ◽

Ammonium Fluoride ◽

Single Step ◽

Electrochemical Anodization ◽

Nanotube Arrays ◽

Surface Areas ◽

High Uniformity ◽

Anodization Process

Self-aligned and high-uniformity carbon (C)- titania (TiO2) nanotube arrays were successfully formed via single step anodization of titanium (Ti) foil at 30 V for 1 h in a bath composed of ethylene glycol (EG), ammonium fluoride (NH4F), and hydrogen peroxide (H2O2). It was well established that applied voltage played an important role in controlling field-assisted oxidation and field-assisted dissolution during electrochemical anodization process. Therefore, the influences of applied voltage on the formation of C-TiO2nanotube arrays were discussed. It was found that a minimal applied voltage of 30 V was required to form the self-aligned and high-uniformity C-TiO2nanotube arrays with diameter of ~75 nm and length of ~2 μm. The samples synthesized using different applied voltages were then subjected to heat treatment for the conversion of amorphous phase to crystalline phase. The photocatalytic activity evaluation of C-TiO2samples was made under degradation of organic dye (methyl orange (MO) solution). The results revealed that controlled nanoarchitecture C-TiO2photocatalyst led to a significant enhancement in photocatalytic activity due to the creation of more specific active surface areas for incident photons absorption from the solar illumination.

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