High-sensitivity amperometric biosensors based on ferrocene-modified linear poly(ethylenimine).

Area of Science:

• Electrochemistry
• Biotechnology
• Materials Science

Background:

• Amperometric biosensors are crucial for detecting biological analytes.
• Efficient electron transfer between enzymes and electrode surfaces is key for biosensor performance.
• Ferrocene-based redox polymers offer tunable electrochemical properties.

Purpose of the Study:

• To develop novel amperometric biosensors for glucose and hydrogen peroxide.
• To evaluate the performance of ferrocene-modified linear poly(ethylenimine) (Fc-LPEI) films for enzyme immobilization.
• To assess the potential of these biosensors for low substrate concentration detection and high current output.

Main Methods:

• Immobilization of glucose oxidase (GOX) and horseradish peroxidase (HRP) in cross-linked Fc-LPEI films.
• Electrochemical characterization of the fabricated biosensors.
• Measurement of current densities and sensitivities at pH 7.

Main Results:

• Glucose sensors achieved limiting catalytic current densities of 1.2 mA/cm2, significantly higher than other ferrocene-based polymers.
• High sensitivity (73 nA/cm2.microM) enabled detection of micromolar glucose concentrations.
• HRP-based sensors showed current densities of 0.9 mA/cm2 and sensitivities of 500 nA/cm2.microM.

Conclusions:

• Fc-LPEI films facilitate effective communication with GOX and HRP.
• The developed biosensors offer high sensitivity and current output, suitable for implantable devices.
• Potential applications include measuring low substrate concentrations and enhancing enzymatic biofuel cells.