MICROMACHINED QUARTZ CRYSTAL RESONATOR ARRAYS FOR BIOANALYTICAL APPLICATIONS

Open Access
Author:
Kao, Ping
Graduate Program:
Electrical Engineering
Degree:
Doctor of Philosophy
Document Type:
Dissertation
Date of Defense:
August 09, 2010
Committee Members:
  • Srinivas A Tadigadapa, Dissertation Advisor
  • Srinivas A Tadigadapa, Committee Chair
  • David Lawrence Allara, Committee Chair
  • Thomas Nelson Jackson, Committee Member
  • Qiming Zhang, Committee Member
  • Melik C Demirel, Committee Member
Keywords:
  • QCM
  • Array
  • Biosensor
  • Protein
  • QCR
  • DNA
  • Micromachined
Abstract:
This work presents the design, fabrication and investigation of high frequency quartz crystal resonator arrays and their application for analyzing interfacial layers and sensing purposes. An 8-pixel micromachined quartz crystal resonator array with a fundamental resonance frequency of ~66 MHz has been fabricated, tested and used in this work. One dimensional model for the characterization of resonator behavior for single or multiple viscoelastic layers under liquid ambient are developed by continuum mechanics approach as well as using an equivalent electrical admittance analysis approach. The investigation of thin interfacial layer between solid (electrode) and liquid phases are reported in terms of the improved resolution of viscoelasitc characteristics of adsorbed layer arising from the use of high frequency resonators. Analyzed layers include globular proteins layer under phosphate buffer solution (PBS) with molecular weights spanning three orders of magnitude, multilayers of avidin and biotin labeled bovine albumin under PBS and diffuse double layer induced by DC bias under 0.5 M sulfuric acid solution. The second half of the dissertation focuses on biosensing applications of quartz resonator arrays. The selective functionalization of 3,3´-Dithiobis (sulfosuccinimidylpropionate) (DTSSP) by physical masking method was first used for specifically detecting avidin molecules. The selective immobilization of thiol modified single stranded DNA probes via electrochemical methods was used for the specific detection of Respiratory Syncytial Virus (RSV) G-gene. The work demonstrates that micromachined quartz crystal resonator arrays could be a powerful analytical tool of investigating interfacial region and can be readily configured as biosenors that can be used for label-free, quantitative assays using extremely small volumes of analytes.