Upload
xiu
View
43
Download
0
Tags:
Embed Size (px)
DESCRIPTION
(3a). (3b). Multiple Electrochemical Systems Using Microfluidic Technology For Detecting Morphine, Nicotine and Bio-indicators. 2.5 cm. (1). Inlet. C.E. R.E. W.E. PDMS 1. (2). PDMS 2. 5.5 cm. PDMS 3. (3). Outlet. 0.6 cm. Glass. (4). ). (3c). Sensing electrodes. (5). 0.5 cm. - PowerPoint PPT Presentation
Citation preview
Sample 2 inlet
Buffer inlet
Pneumatic micropump
The vitamin C filtration
Micro-valve
outletSample 1 inlet
MIP morphine sensing electrode
Pt PtAg
Multiple Electrochemical Systems Using Microfluidic Technology For Detecting Morphine, Nicotine and Bio-indicators
Chen Hsun Weng1, Gwo Bin Lee1, Tse Chuan Chou2, Kun Chuan Ho3, Wei Yin Liao2, Wei Ming Yeh3, Chen Tar Wu3 1Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan2Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan 3Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan
This study reports a hand-held bio-sensing system capable of sensing multiple bio-indicators using microfluidics and electrochemical sensing techniques. The multi-functional bio-sensing system is composed of three modules, namely electrochemical sensing electrodes, a micropump module, and a controller module. Modular design of the multiple sensing systems allows one to integrate flow control devices and bio-sensing devices on a single chip. Experimental data show that several sensing system, including morphine, nicotine, pH value, calcium ion, potassium ion, and ammonium ion, glucose, and albumin, can be successfully detected using the developed hand-held system.
Morphine-MIP sensing system
Nicotine-MIP sensing system
Bio-indicators detecting system
Introduction
11.5 cm
4.5
cm
0 100 200 300 4000
10
20
30
40
50
60
0.2 mM
0.1
0.075
0.05
0.025
Cur
rent
den
sity
(A
/cm
2 )
time (sec)
MIPf=150E=0.45 V0.02 M PBS (pH=7.4)
0.01
0 100 200 300 4000
5
10
15
20
25
Cu
rren
t d
ensi
ty
(A
/cm
2 )
time (sec)
MIP
E= 0.45 V
f = 20 (92.31 l/min)
0.1 mM MO
PBS
response time = 22.2 sec
recovery time = 91.6 sec
We use 3, 4-Ethylenedioxythiophene (EDOT) regarded as a monomer. By electropolymerizing, EDOT will wrap up and cover the morphine to become MIP-EDOTMO
on the platinum (Pt) electrode. Then morphine can be detected with the potentiostatic method. When the velocity of the flow by the micropumps was controlled with 2.31μl/min , the sensitivity of MIP-morphine sensor was171.47μA/cm2*mM , ranging from 0.01 to 0.2 mM 。 The detection limit was 0.2μM ( S/N= 3 ) . The morphine sensing chip was fabricated by using MEMS techniques and incorporates PDMS microstructures that combined micro-channels, micropumps and microvalves to detect morphine with three-electrodes.
inlet
outlet
air control channelMicropump module
Sensing module Pt electrode Ag electrode
PDMS1
PDMS2PDMS3
glass
)
The fixed amount of bio-samples can be successfully transported to the sensing electrode array which was composed of four pairs of two-electrode systems (reference and working electrodes) for measuring pH, calcium ion, potassium ion, and ammonium ion concentrations of the solutions. Figure 6 shows the relationship between the concentration of bio-indicators and output potential. It is found that the sensitivity of pH, calcium, potassium, and ammonium ions are 74.4mV/pH, 27 mV/pCa2+, 54mV/pK+, and 55mV/pNH4+, respectively.
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(3a) (3b)
(3c)
PDMS 1PDMS 2 PDMS 3
Glass
Sensing electrodes
Inlet
Outlet
Micropump Microchannel
C.E.R.E.W.E.
5.5 cm
2.5
cm
0.5 cm
0.6
cm
This study reports a hand-held sensing system capable of sensing nicotine (NIC) using a novel combination of microfluidics, electrochemical sensing, and molecular imprinting polymer techniques. The sensing system can sense the concentration of NIC by fabricating NIC-imprinted TiO2 sites on a microelectrode in an automatic format [1]. The modular design of the sensing systems allows us to integrate a microfluidic control module and an electrochemical sensing module for a sensitive and selective detection of NIC. The microfluidic control module is composed microchannels, micropumps and microvalves, which can transport a precise amount of bio-sample to the sensing electrodes and automate the whole sensing process. Experimental data reveal that the concentration of NIC can be successfully detected using the developed hand-held system.
MEMS design and Micro-fabrication LabMML2006