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LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Dynamic Thermoelectric Glucose Sensing with Layer-by-Layer Glucose Oxidase
Immobilization
Siva Mahesh Tangutooru1
V.L. Kopparthy, R. Gumma, G.G. Nestorova, E.J. Guilbeau
Center for Biomedical Engineering and Rehabilitation Science
Louisiana Tech University
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
GoalTo develop a microfluidic glucose calorimeter by immobilizing glucose oxidase using layer-by-layer self-assembly.
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
• Principle of thermoelectricity• Calorimeter design and measurement system• Layer-by-layer self-assembly procedure• Results• Conclusion• Future work
Presentation Summary
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Thermoelectric detection of glucose𝐺𝑙𝑢𝑐𝑜𝑠𝑒+𝑂2+𝐻2𝑂𝑔𝑙𝑢𝑐𝑜𝑠𝑒𝑜𝑥𝑖𝑑𝑎𝑠𝑒
→𝐺𝑙𝑢𝑐𝑜𝑛𝑖𝑐𝑎𝑐𝑖𝑑+𝐻2𝑂2+79𝑘𝐽 /𝑚𝑜𝑙
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Device fabrication
Inlet 1
Inlet 2
Outlet
(a)
(b)
(c)
(d)
(a)
Thermopile
a) PDMS inlet & outlet connectorsb) Microscope glass slidec) Kapton® taped) Microscope glass coverslip
Microfluidic Calorimeter
Microfluidic Device
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Experimental measurement system
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Hydrodynamic focusing
G. G. Nestorova and E. J. Guilbeau, "Thermoelectric method for sequencing DNA," Lab on a Chip, vol. 11, pp. 1761-1769.
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Polyelectrolyte GlucoseOxidase
SO3- Na+
PSS
N+
H2PEI
PEIPSS
PEIGlucose Oxidase(a)
(b) (c)
Layer-by-layer electrostatic adsorption mechanism. (a)General adsorption procedure
of ployelectrolytes on a substrate.
(b)Layer-by-layer assembly of glucose oxidase on the substrate.
(c) Structure of polyelectrolytes used for LbL assembly.
Immobilization procedure for LbL assembly.
Layer-by-layer self assembly
K. Ariga, Y. Lvov “Self-Assembly of Functional Protein Multilayers: From Flat Films to Microtemplate Encapsulation”, “Biopolymers at Interfaces” Ed. M. Malmsten, M. Dekker Publ., 2003, NY, p.367-391.
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Our novel glucose calorimeter– Calorimeter
• Self-generating signal• No external power requirement• Relatively inexpensive• Small in size and light weight• High rejection of common mode thermal signals• Relatively simple to manufacture• Rugged and durable
– Layer-by-layer Immobilization• Multiple layers are physically adsorbed.• Easy preparation and high bond strength.
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Sensor response for glucose concentration
100 mg/dL 75 mg/dL
Flow rates: 100 µl min-1 and 25 µl min-1 No. of Immobilized glucose oxidase layers: 2
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Effect of number of immobilized layers on sensor response
Flow rates: 100 µl min-1 and 25 µl min-1
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Effect of flow rates on sensor response
No. of Immobilized glucose oxidase layers: 2
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Conclusion• Successfully immobilized multiple layers of glucose oxidase
using LbL self-assembly.• Multiple layers of glucose oxidase had little effect because
oxygen limited the reaction. • Increasing the ratio of inlet flow rates improved calorimeter
response.
Future work• This thermoelectric method can be employed to detect the
enthalpy produced by enzymatic reactions.– glutamate concentration detection in the flow stream by immobilizing
glutamate oxidase using layer-by-layer self-assembly.
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
Thank you
Questions ???
LOUISIANA TECH UNIVERSITYCollege of Engineering and Science
M. J. Muehlbauer, E. J. Guilbeau, and B. C. Towe, "Applications and stability of a thermoelectric enzyme sensor," Sensors & Actuators: B. Chemical, vol. 2, pp. 223-232, 1990.