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Synthesis and characterization of conducting polyaniline/iron oxide (PAni/Fe3O4) nanorods for immunosensing application

Adamu, Mahmoud Auwal (2017) Synthesis and characterization of conducting polyaniline/iron oxide (PAni/Fe3O4) nanorods for immunosensing application. PhD thesis, Universiti Tun Hussein Onn Malaysia.


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The development of the current electrochemical biosensors is geared towards the simplification and improvement of the transduction pathway. Nevertheless, recently the modification of transducers with nanomaterials has been extensively studied and conveys many advantages. In this work, electrochemical immunosensors were obtained after the modification of FTO coated glass with the synthesize conducting PAni-Fe3O4 nanocomposites forming a modified (PAni-Fe3O4/FTO) electrode on which anti-β-Amyloid was immobilized on the new electrode for detection of Alzheimer’s diseases. The new improve physical and electrical properties of the nanocomposites such as enhanced conductivity and area/volume ratio facilitates transduction process and biomolecules adsorption. The PAni-Fe3O4 have a nanorod structure and are electrically conductive. The presence of small red shift and a slight blue shift in UV-Vis spectra is an indication of a successful electrode modification. FT-IR spectrum of immunosensor exhibits additional absorption bands at 1932 cm−1 (carbonyl stretch), 3213 cm−1 and 2113 cm−1 (N–H stretching), indicating the immobilization of anti-β-Amyloid on PAni/Fe3O4/FTO surface. The AFM studies showed the value of the roughness of the modified electrode to be 50.13 nm which is higher than that of the bare FTO (27.49 nm) thus, indicating increased available surface and porous morphology that allows more adsorption of antibodies on the surface. The immunosensor exhibited a specific response after incubation with β- Amyloid at the range of 0.01 down to 0.00001 μg mL-1. The linear regression equation was found to be y = 0.04431x + 0.00142 and correlation coefficient of 0.947. The limit of detection was calculated to be 0.0023 μgmL−1 at 3σ. The modified electrode showed a better sensitizing effect and stability as immobilization support/matrices. The results of these studies have implications for the application of this interesting matrix (PAni- Fe3O4) toward the development of other biosensors.

Item Type: Thesis (PhD)
Subjects: T Technology > TA Engineering (General). Civil engineering (General) > TA401-492 Materials of engineering and construction. Mechanics of materials
Depositing User: Mr. Mohammad Shaifulrip Ithnin
Date Deposited: 13 Aug 2018 03:28
Last Modified: 13 Aug 2018 03:28
URI: http://eprints.uthm.edu.my/id/eprint/10251
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