Transcript Document

2-Dimensional SPR Detection System Integrated with Molecular
Imprinting Polymer Microarrays Using Microfluidic Technology
Kuo-Hoong Lee, Yuan-Deng Su, Shean-Jen Chen and Gwo-Bin Lee
Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan 701
Abstract
This study reports a novel microfluidic chip integrated with arrayed molecular imprinting polymer (MIP) films for surface plasmon
resonance (SPR) phase imaging of specific bio-samples. The SPR imaging system uses a surface-sensitive optical technique to detect twodimensional spatial phase variation caused by bio-molecules absorbed on a sensing surface composed of highly-specific MIP films. The developed
system has a high resolution and a high-throughput screening capability and has been successfully applied to the analysis of multiple biomolecules without the need for additional labeling in long-term measuring.
PDMS layer1 & layer2
Design
PDMS layer3
Results
Temp.
Sensor
Inlet
Temperature (oC)
Arrayed
MIP films
θ1
Microvalve
prism
Microchannel
Heater
Micropump
Glass
Slide(SF-11)
Au (47.5 nm)
Micropump
(a)
6 cm
Gold film
Microchannel
Micropump/valve
Glass
Inlet
Inlet
Temp. Sensor
Heater
Outlet
Arrayed MIP
A SPR/MIP microfluidic chip comprising
microchannels, micropumps/microvalves,
micro-heaters and temperature sensors
coupled with a 2-D SPR imaging system
was developed. Micropumps were used to
automate the sample injection. A
micromachine-based temperature control
module comprised of micro-heaters and a
temperature sensor was used to maintain
the temperature during measurement.
Microchannel
(SF-11)
-11)
Slide (SF
Cleaning
Sputtering 47.5nm Au
0
25
50
75
100
Heater
(b)
(a) Schematic illustration of the arrayed
SPR/MIP microfluidic chip (b) Crosssectional view showing that three layers of
PDMS could be used to transport samples
from inlet to outlet through the arrayed MIP
films.
SU-8 Mold
PDMS replication
Temp. sensor
Heater
MIP Reactor
Temp. Sensor
200µm
Glass
30
Time (s)
Sensor
Slide
35
25
PDMS #2
PDMS #1
Fabrication
Si
40
Outlet
PDMS #3
The temperature control system can heated up
bio-samples to 37 °C within 20s and kept them
at a uniform temperature.
50
Pumping rate (ul/min)
CCD
4 cm
He-Ne laser
45
Outlet
25 psi
20 psi
15 psi
10 psi
40
30
20
10
50µm
(b)
(a)
Heater
Lithography
0
5
10
15
20
Freq. (Hz)
SU-8 molding
Thiol group modification
(e)
PDMS replication
Micropump
Pt deposition
MIP spin coating and polymerization
Microvalve
(b)
PDMS release / Via hole formation
The relationship between the pumping rate and
the driving frequency.
(c)
PR lift-off
Au lead deposition
(a)
(c)
Assembly
Simplified fabrication process of the
SPR/MIP microfluidic chip. (a) SU-8
molding and PDMS casting fabrication
process; (b) Spin-coating of MIP films and
polymerization process; (c) Temperature
sensor and heaters fabricated by using liftoff technique.
Conclusions
A novel SPR/MIP microfluidic chip
integrated with arrayed MIP films for
SPR phase imaging of specific biosamples was developed.
Multiple MIP films could be used for
highly-sensitive, highly-specific biosensing.
The development of the SPR/MIP
microfluidic chip can be promising for
nano-sensing applications and can
detect bio-samples with a low
molecular weight.
SEM images of the SU-8 molds (a and c)
and PDMS replicas (b and d) of the arrayed
MIP reactors and micropumps/valves. (e)
the temperature sensor and heater.
0.01
SPR angle shift (deg)
PDMS bonding
(d)
0.008
Arrived saturation
(a)
Washed with ethanol
0.006
(b)
(a) SPR phase interference image and (b)
phase reconstructed image when ethanol flows
through the arrayed MIP films.
0.004
0.002
Acknowledgements
0
0
50
100
Time (min)
150
The authors gratefully acknowledge the
Flowed progesterone sample
financial support provided to this study by the
The detection kinetics of 50 μM progesterone. MOE Program for Promoting Academic
Reaction procedure (0 ~ 21 min : ethanol, 21 ~ Excellence of Universities (Grant number EX126 min : ethanol + 50μM progesterone, 126 A-91-E-FA08-1-4).
min ~ : ethanol).
2006
MML
MEMS design and Micro-fabrication Lab