Optimisation and characterisation of biosensors based on polyaniline

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Biosensor performance relies heavily on the characteristics of its constituent layers.
• Increasing demands for lower detection limits and enhanced stability necessitate detailed sensor component analysis.

Purpose of the Study:

• To optimize and characterize a conductive polymer layer (polyaniline) and an immobilized protein layer for biosensor applications.
• To investigate the impact of polyaniline film thickness on amperometric sensor performance characteristics.
• To visualize protein immobilization and understand its relationship with sensor performance.

Main Methods:

• Electrochemical deposition of polyaniline films onto screen-printed electrodes.
• Analysis of amperometric sensor performance metrics including steady-state time, charging current, catalytic current, background current, and signal/background ratios.
• Scanning electron microscopy with gold-labeled antibodies and back-scattered electron detection for protein visualization.

Main Results:

• Polyaniline film thickness significantly influences conductivity, morphology, and various amperometric sensor performance characteristics.
• Direct visualization of protein groups on the sensor surface was achieved, correlating with protein concentration.
• Optimized polyaniline layers contribute to improved sensor signal and reduced background noise.

Conclusions:

• Characterization of polyaniline layer thickness is crucial for optimizing amperometric biosensor performance.
• Direct visualization techniques provide valuable insights into protein immobilization and its impact on sensor functionality.
• This work lays the foundation for developing more sensitive and stable biosensor devices.