Development of On-chip DNA Sensor Using Wettability
Date Issued
2010
Date
2010
Author(s)
Kan, Chen-Hao
Abstract
The main objective of this paper is to develop a passive DNA hybridization sensor, which drives the analyte by capillary force and combines the concept of reversed contact angle gradient as a fluid valve. We propose a sensing concept that uses the change of the wettability before and after DNA hybridization, which is different from typical optical, electrochemical, or mass-sensitive sensor. Also, we design a series of preliminary experiments to approach this concept. The device we propose is a glass which immobilizes the hydrophobicity-modified DNA on a stripe region, covers a PDMS micro-channel that can draw the analytic fluids in through capillary force. After hybridizing with complementary DNA, the hydrophobic region will turn to be relatively hydrophilic due to the polarity of DNA molecule, so that the fluids can keep creeping through the micro-channel. Consequently, we can sense the DNA very intuitively with the device.
We will observe the capillary effect in the micro-channel, design the geometry of the device, create a reversed gradient surface to test how it affects the fluids in the micro-channel, establish the contact angle database of the SAM and probe DNA surface, and record the change of wettability before and after hybridization. After summing up these results, we will discuss the applicant on passive device through the bio-chemical surface we have tested and the possibility to realize the concept we propose.
We use SAM, DNA immobilization technology, and PDMS material, combine MEMS process to provide a new sensing concept. With these simple process and bio-chemical surface data, this paper can be a reference while designing another passive sensor. Meanwhile, we hope this can inspire more sensing concept.
Subjects
DNA
sensor
hybridization
passive
capillary
wettability
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