NANOMATERIAL PLATFORMS FOR ENHANCED BIOMOLECULAR DETECTION

Open Access
Author:
Parajuli, Omkar R.
Graduate Program:
Chemistry
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
March 04, 2010
Committee Members:
  • Jong In Hahm, Dissertation Advisor
  • Thomas E Mallouk, Committee Chair
  • Jong In Hahm, Committee Chair
  • John V Badding, Committee Member
  • Jian Xu, Committee Member
Keywords:
  • Zinc Oxide nano rod array
  • Copper silicide
  • polymer thin film
Abstract:
This thesis focuses mainly on two areas; the enzymatic activity and adsorption behavior of proteins onto the diblock copolymer thin film templates and the method of creating high quality ZnO nanorod arrays and using the fluorescence enhancing ZnO for bio-sensing applications. Following an introduction, chapter 2 describes the qualitative and quantitative enzymatic activity of protein arrays on PS-b-PMMA thin film and shows that the deposited proteins retain their characteristic catalytic properties even after surface immobilization. Comparative protein adsorption behavior of proteins on different polymer thin films is discussed in Chapter 3, showing that the PS-b-PMMA is better than homopolymers PS or PMMA and polymer blend PS/PMMA thin films. Chapter 4 describes the method of creating high quality ZnO NR array and further discusses a highly sensitive and effective telomeric repeat elongation (TRE) assay by exploiting the fluorescence signal enhancing ability of ZnO NR platforms. This result shows that the novel ZnO-base TRE assays can be successfully used for detecting active telomerase. As telomerase is a useful biomarker in cancer diagnosis and screening, our ZnO NR-based TRE assays may prove to be not only useful in basic biological research but also in clinical testing. In Chapter 5, ZnO platforms are further exploited in ultrasensitive detection of disease biomarkers cytokines. The detection sensitivity achieved by using ZnO NR method is in the subfemtogram per milliliter level, which is 3-4 orders of magnitude more sensitive than the conventional assay detection limits. This detection sensitivity is achieved without the need for indirect enzyme reactions of specialized instrumentation. The final chapter presents a highly unexpected finding of self-aligned, self-assembled copper silicide nanobeams on silicon substrate which is used as catalyst and support for carbon nanotube cantilever growth.