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Electrodeposition of Pt nanostructures and its Application as Glucose Sensor

Mahshid, Sahar Sadat | 2011

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  1. Type of Document: Ph.D. Dissertation
  2. Language: Farsi
  3. Document No: 42317 (07)
  4. University: Sharif University of Technology
  5. Department: Materials science and Engineering
  6. Advisor(s): Dolati, Abolghasem; Ghorbani, Mohammad
  7. Abstract:
  8. The present work describes sensing application of modified Pt nanostructures towards detection of glucose. Modified Pt nanostructured electrodes were prepared using electrodeposition method such as chronoampermetry and potentiostatic pulse methods. The electrodeposition of Pt nanostructures was first studied by voltammetry and amperommetry techniques and then potentiostatic pulse method has been used to produce the alloyed structures of platinum. In this regard, the first electrode was proposed based on alloyed Pt/Ni nanowire arrays (NWAs) for the non-enzymatic detection of glucose. The Pt/Ni NWAs were prepared by pulse electrodeposition of Pt and Ni within a nano-pore polycarbonate (PC) membrane followed by a chemical etching of the membrane. The resulting Pt/Ni NWAs electrode showed high electrocatalytic activities towards the oxidation of glucose in alkaline solution. Consequently, a sensitive amperometric detection of glucose is achieved under 0.45 V vs. SCE with a low detection limit of 1.5 µM within a wide linear ranges from 0 to 1.5 µM and 2 to 7 mM (R = 0.997). The sensitivity of 960 and 334 μAmM-1 cm-2 has been achieved, respectively. Afterward, the second electrode consisting of Pt, Ni and Co has been utilized to decorate a nanowire arrays system and create an electrode, Pt/Ni-Co NWAs, as a highly efficient non-enzymatic glucose sensor. In this regard, addition of Co resulted in a strong amperometric response at lower applied potential than that of Pt/Ni NWAs. The resulting electrode had two linear ranges of 0 – 1 mM and 1 – 8 mM glucose addition with sensitivity of 636 and 316 μAmM-1 cm-2, respectively. Low detection limit of 1 µM could be also obtained. Finally, the third electrode has been produced by electrodeposition of Pt and Ni nanostructures on TiO2 nanotubes in a single-bath solution. In this regard, the pulse electrodeposition was chosen to decorate the TiO2 nanotubes in various conditions and the resultant modified electrode was designed through a six-step pulse deposition. Selection of the proper electrodeposition condition was done through a series of scanning electron microscopy (SEM) characterization. In this regard, the six-step pulse deposition was designed in a way that there were two deposition steps at first and forth steps which were -0.3 and -4, respectively and each of them was followed by an anodic step and a resting step in each pulse. Afterward, the proposed electrode was tested for the catalytic activity toward glucose. It had two linear ranges for detection of glucose from 0 to 0.15 mM and from 0.1 to 10 mM with the detection sensitivity of 1629 and 230 μAmM−1 cm−2 respectively. Moreover, its experimental detection limit was 0.5 μM (Signal/Noise = 3). Furthermore, the three electrodes were tested with the glucose in the absence and presence of oxidable species such as ascorbic acid and uric acid. The results confirmed that the three electrodes showed no significant signals of interferences, among which the Pt/Ni TiO2 NTs electrode could more successfully avoid the interferences. It is due to the ultra-fine nanostructures covering the whole surface of the mentioned electrode with large effective surface area
  9. Keywords:
  10. Platinum ; One Dimentional Nanostructure ; Titanium Oxide Nanotube ; Glucose ; Biosensor ; Electrodeposition

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