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Published on: June 1, 2018
Supramolecular multilayer structures of wired redox enzyme electrodes
Ernesto J Calvo1, Claudia B Danilowicz, Alejandro Wolosiuk
1INQUIMAE, Departamento de Química Inórganica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Pabellón 2 Ciudad Universitaria, AR-1428 Buenos Aires, Argentina. calvo@qi.fcen.uba.ar
Physical Chemistry Chemical Physics : PCCP
|October 1, 2009
Summary
This study presents reagentless glucose biosensors built using layer-by-layer assembly of glucose oxidase (GOx) and a mediator. The biosensors show increased catalytic current with more layers, indicating enhanced enzyme loading and efficient glucose oxidation.
Area of Science:
- Electrochemistry
- Biomaterials Science
- Nanotechnology
Background:
- Development of reagentless biosensors is crucial for continuous monitoring.
- Layer-by-layer (LBL) assembly offers precise control over multilayer film fabrication.
- Osmium complexes are effective redox mediators for enzyme-based biosensors.
Purpose of the Study:
- To fabricate and characterize supramolecular multilayer glucose biosensors using LBL assembly.
- To investigate the enzyme kinetics and performance of reagentless glucose detection.
- To determine the concentration and activity of the immobilized glucose oxidase.
Main Methods:
- Alternate layer-by-layer (LBL) electrostatic adsorption of glucose oxidase (GOx) and Os complex derivatised poly(allylamine) (PAH-Os).
- Electrochemical characterization of modified electrodes to analyze catalytic current dependence on glucose concentration.
- Quartz crystal microbalance (QCM) for measuring enzyme surface concentration during adsorption.
- Ellipsometry for estimating osmium volume concentration and film thickness.
Main Results:
- Successful fabrication of multilayer biosensors with integrated mediator.
- Enzyme kinetic parameters and surface concentration of "wired" enzyme (GammaE) were determined.
- Catalytic current increased with the number of LBL layers due to higher enzyme loading.
- Efficiency of enzyme FADH2 oxidation by the Os redox polymer remained constant at approximately 2 x 10^4 M^-1 s^-1, except for the initial layer.
Conclusions:
- LBL assembly is an effective method for creating reagentless glucose biosensors.
- The biosensor performance is directly related to enzyme loading and mediator efficiency.
- The developed biosensors demonstrate potential for accurate and continuous glucose monitoring.
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