Dynamic Thermoelectric Glucose sensing with Layer-by-Layer Glucose Oxidase Immobilization

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


GoalTo develop a microfluidic glucose calorimeter by immobilizing glucose oxidase using layer-by-layer self-assembly.


• Principle of thermoelectricity• Calorimeter design and measurement system• Layer-by-layer self-assembly procedure• Results• Conclusion• Future work

Presentation Summary


Thermoelectric detection of glucose𝐺𝑙𝑢𝑐𝑜𝑠𝑒+𝑂2+𝐻2𝑂𝑔𝑙𝑢𝑐𝑜𝑠𝑒𝑜𝑥𝑖𝑑𝑎𝑠𝑒

→𝐺𝑙𝑢𝑐𝑜𝑛𝑖𝑐𝑎𝑐𝑖𝑑+𝐻2𝑂2+79𝑘𝐽 /𝑚𝑜𝑙


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


Experimental measurement system


Hydrodynamic focusing

G. G. Nestorova and E. J. Guilbeau, "Thermoelectric method for sequencing DNA," Lab on a Chip, vol. 11, pp. 1761-1769.


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.


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.


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


Effect of number of immobilized layers on sensor response

Flow rates: 100 µl min-1 and 25 µl min-1


Effect of flow rates on sensor response

No. of Immobilized glucose oxidase layers: 2


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.


Thank you

Questions ???


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.

Documents

Dynamic Thermoelectric Glucose sensing with Layer-by-Layer Glucose Oxidase Immobilization