Hamzah, Irni Hamiza
(2013)
Design, Fabrication And Characterization Of
Fr4-Based Dna Label Free Sensor Integrated With
Pocket-Sized Readout Circuitry.
PhD thesis, Universiti Sains Malaysia.
Abstract
Silicon, glass and ceramic are commonly base substrates used in SU8 film
fabrication and DNA biosensor. All these substrates are biocompatible, expensive, hard
and brittle, difficult for drilling and dicing, requires expensive equipments and complex
methodology of fabrication. Microcracks are often found on SU8 film due to the large
gap of thermal expansion coefficient (TEC) between silicon/glass and SU8. In addition,
the use of bulky equipments and accessories that must be interfaced with hardware
and software through a central processing unit (CPU) limits the portability of the whole
biosensor system. Hence, the aim of this work is to investigate on the suitability of
polymethylmethacrylate (PMMA) to be used as a base substrate for SU8 film
fabrication and the application of a non-biocompatible material, flame retardant 4 (FR4)
as a base substrate for a label free DNA biosensor. A portable and handy readout
circuitry with double-sided pocket-sized of PCB for DNA detection through current
measurement cyclic voltammetry (CV) method has been developed and integrated with
the FR4-based fabricated sensor. The Au is fabricated throughout all conducting tracks
on the FR4 and the characterization of the fabricated FR4-based sensor to perform CV
reversible process is confirmed by a series of analysis. The thiol group at the 3’-end of
ssDNA is used to link the DNA with the Au surface and act as probe DNAs. Two types
of target DNAs which consist of complementary nucleobase sequence and
noncomplementary nucleobase sequence are used to investigate on the hybridization
mechanism with the probe DNAs.
Actions (login required)
 |
View Item |
