Suspended carbon nanowire biosensor for rapid and label-free salmonella detection / Aung Thiha

Aung , Thiha (2020) Suspended carbon nanowire biosensor for rapid and label-free salmonella detection / Aung Thiha. PhD thesis, Universiti Malaya.

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      Carbon, the building block life, is rapidly becoming the building block of nextgeneration electronics and sensor materials. Of many ways to handle nanocarbon materials, Carbon Microelectromechanical Systems (C-MEMS) emerges as a unique way for top-down fabrication of three-dimensional carbon micro to nanostructures. In this work, the use of C-MEMS techniques in nanowire biosensor fabrication is explored. Two main hindrances in the use of C-MEMS carbon structures for biosensing lie in miniaturization to nanoscale sensor material and inertness of as-fabricated carbon. This dissertation presents ways to overcome these limitations. First, miniaturization to patterned sub-100 nm carbon nanowires was achieved by optimization of ectrospinning properties and integration of electrospinning photoresist polymer with photolithographic pelatterning. Secondly, a microplasma direct writing technique was developed as a novel non-destructive technique for selective surface functionalization of C-MEMS manufactured carbon electrodes. This method uses a simple setup to pattern carboxylic functional groups on the carbon surface at atmospheric conditions. Surface oxygen percentage as high as 27% has been observed. The fabricated suspended carbon nanowires were integrated with microfluidics and immobilized with biomolecular probes for biosensing. Nanowire biosensing was demonstrated by developing an aptamer-based assay that can detect whole-cell Salmonella. The carbon nanowire biosensor used chemiresistive biosensing to achieve rapid detection of the pathogen with high sensitivity and specificity with a detection limit of 10 CFU/mL, which is more sensitive than conventional methods of detecting bacteria.

      Item Type: Thesis (PhD)
      Additional Information: Thesis (PhD) - Faculty of Engineering, Universiti Malaya, 2020.
      Uncontrolled Keywords: Salmonella; Biosensing; Carbon Microelectromechanical Systems (C-MEMS); Carbon nanowires; Bacteria
      Subjects: R Medicine > R Medicine (General)
      T Technology > TA Engineering (General). Civil engineering (General)
      Divisions: Faculty of Engineering
      Depositing User: Mr Mohd Safri Tahir
      Date Deposited: 24 Sep 2021 06:54
      Last Modified: 09 Jan 2023 07:12

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