Carbon-on-Gold Films and Spontaneous Adsorption of Aryldiazonium Salts for Surface Plasmon Resonance Sensing

• Author / Creator

  Nguyen, Thuy

• Over the past decades, surface plasmon resonance (SPR) technology has gained popularity as a powerful analytical technique for the study of biomolecular interactions and medical diagnostics. This is made possible thanks to the well-established gold-thiolate chemistry. However, the limited sensitivity and long-term stability of gold substrates and alkanethiol self-assembled monolayers motivate us to explore lamellar carbon-on-metal structures as SPR substrates and the spontaneous adsorption of aryldiazonium salts as surface functionalization strategies.
  Our electron-beam evaporation process allows very thin, defect-free, well-adhered carbon films to be deposited on metal substrates, leading to minimal sensitivity loss for carbon-on-gold films and enhanced sensitivity for carbon-on-silver films in SPR measurements compared with previous reports. With further optimization of the deposition process and SPR instrumental setup, we believe that the sensitivity of carbon-on-silver films can be increased even more.
  Spontaneous adsorption of aryldiazonium salts provides a fast and simple strategy to pattern surfaces selectively with stable monolayers of chemical linkers, which are viable for the covalent attachment of biomolecules on SPR substrates. This surface chemistry, together with carbon-on-gold films, were utilized to develop a proof-of-concept immunoassay, showing improved performance compared with the physical adsorption of biomolecules.
  This thesis demonstrates that a combination of carbon-on-metal films and spontaneously grafted diazonium layers can be a potential alternative to Au-thiolate SAMs for SPR sensing, thereby improving the performance of SPR-based biosensors. What is more, carbon-on-metal substrates also have potential as a versatile analytical platform that are compatible with not only SPR but also electrochemistry and SERS techniques, opening a pathway for new, exciting nanostructures and sensing schemes to be developed with analysis power never seen before.

• Subjects / Keywords

  • Surface Plasmon Resonance
  • Biosensors
  • Immunoassays
  • Carbon electrodes
  • Surface chemistry
  • Diazonium chemistry
  • Carbon-on-gold films

• Graduation date

  Fall 2021

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/r3-83wv-js83

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.