ULTRASENSITIVE BIOMOLECULAR DETECTION ENABLED BY NANOMATERIALS

Open Access
Author:
Adalsteinsson, Viktor Arnarson
Area of Honors:
Chemical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Dr Jong In Hahm, Thesis Supervisor
  • Jong In Hahm, Thesis Supervisor
  • Themis Matsoukas, Honors Advisor
Keywords:
  • IL-18
  • Nanowires
  • ZnO
  • TNF-alpha
  • Direct Assay
  • Sandwich Assay
Abstract:
A review of various publications is first given as a background and introduction to the field of nanoscale biosensors. Afterwards, the actual biosensor development undertaken as honors thesis research is presented: the ultrasensitive detection of cytokines enabled by nanoscale ZnO arrays. By achieving subfemtogram per milliliter detection sensitivity in these ZnO nanoarray biosensors, cytokines implicated in the pathogenesis of acute kidney injury (AKI), such as interleukin-18 and tumor necrosis factor-α, may be identified at trace levels within human urine. In the clinical setting, this achievement holds great promise for permitting early disease detection and thereby, improving a patient’s prognosis. A 3-4 order of magnitude increase in diagnostic power has been gained over conventional assays by exploiting the wide band gap and large exciton binding energy of nanoscale ZnO arrays in fluorescent assays. Measured signals are shown to directly correlate with cytokine concentrations in both direct and sandwich assays involving both pure buffer and urine. Therefore, robust, high-throughput biosensors with unparalleled levels of sensitivity have been developed and described for potential use in the early detection of cytokine-implicated diseases (Adalsteinsson et al. 2008).