TY - JOUR
T1 - Enzyme kinetic measurements using a droplet-based microfluidic system with a concentration gradient
AU - Bui, Minh Phuong Ngoc
AU - Li, Cheng Ai
AU - Han, Kwi Nam
AU - Choo, Jaebum
AU - Lee, Eun Kyu
AU - Seong, Gi Hun
PY - 2011/3/1
Y1 - 2011/3/1
N2 - In this paper, we propose a microfluidic device that is capable of generating a concentration gradient followed by parallel droplet formation within channels with a simple T-junction geometry. Linear concentration gradient profiles can be obtained based on fluid diffusion under laminar flow. Optimized conditions for generating a linear concentration gradient and parallel droplet formation were investigated using fluorescent dye. The concentration gradient profile under diffusive mixing was dominated by the flow rate at sample inlets, while parallel droplet formation was affected by the channel geometry at both the inlet and outlet. The microfluidic device was experimentally characterized using optimal layout and operating conditions selected through a design process. Furthermore, in situ enzyme kinetic measurements of the β-galactosidase- catalyzed hydrolysis of resorufin-β-d-galactopyranoside were performed to demonstrate the application potential of our simple, time-effective, and low sample volume microfluidic device. We expect that, in addition to enzyme kinetics, drug screening and clinical diagnostic tests can be rapidly and accurately performed using this droplet-based microfluidic system.
AB - In this paper, we propose a microfluidic device that is capable of generating a concentration gradient followed by parallel droplet formation within channels with a simple T-junction geometry. Linear concentration gradient profiles can be obtained based on fluid diffusion under laminar flow. Optimized conditions for generating a linear concentration gradient and parallel droplet formation were investigated using fluorescent dye. The concentration gradient profile under diffusive mixing was dominated by the flow rate at sample inlets, while parallel droplet formation was affected by the channel geometry at both the inlet and outlet. The microfluidic device was experimentally characterized using optimal layout and operating conditions selected through a design process. Furthermore, in situ enzyme kinetic measurements of the β-galactosidase- catalyzed hydrolysis of resorufin-β-d-galactopyranoside were performed to demonstrate the application potential of our simple, time-effective, and low sample volume microfluidic device. We expect that, in addition to enzyme kinetics, drug screening and clinical diagnostic tests can be rapidly and accurately performed using this droplet-based microfluidic system.
UR - http://www.scopus.com/inward/record.url?scp=79952147403&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79952147403&partnerID=8YFLogxK
U2 - 10.1021/ac102472a
DO - 10.1021/ac102472a
M3 - Article
C2 - 21280615
AN - SCOPUS:79952147403
SN - 0003-2700
VL - 83
SP - 1603
EP - 1608
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 5
ER -