A novel electrochemical biosensing method with double-layered polymer brush modified electrode.

Area of Science:

• Electrochemistry
• Materials Science
• Biotechnology

Background:

• Electrochemical biosensors often suffer from high background noise, limiting their sensitivity and accuracy.
• Controlling biomolecule adsorption and desorption is crucial for effective biosensing.
• Existing surface modification methods may not adequately reduce background noise or precisely control surface properties.

Purpose of the Study:

• To develop a novel conductive substrate with a double-layered polymer brush structure for electrochemical biosensors.
• To investigate the ability of this structure to reduce background noise and control biomolecule interactions.
• To evaluate the performance of the new biosensor electrode for DNA detection.

Main Methods:

• Fabrication of a gold electrode modified with a hydrophobic poly(tert-butyl methacrylate) brush layer.
• Acid treatment to create a hydrophilic carboxy group on the outermost surface, forming a double-layered structure.
• Surface characterization using wettability and optical analyses.
• Electrochemical measurements to assess the correlation between potential difference and hydrogen ion concentration.
• Comparison with gold electrodes modified with self-assembled monolayers (COOH-SAM).
• Evaluation of DNA capture efficiency on the modified electrode.

Main Results:

• The double-layered polymer brush structure was successfully fabricated and confirmed by surface analyses.
• A linear correlation was observed between potential difference and hydrogen ion concentration on the modified electrode, indicating pH responsiveness.
• This pH responsiveness was significantly enhanced compared to electrodes with COOH-SAM.
• The double-layered structure effectively reduced background noise, leading to more efficient target DNA capture.
• The hydrophobic inner layer stabilized the surface, enhancing the performance of the outermost hydrophilic layer.

Conclusions:

• The developed double-layered polymer brush structure is a highly effective surface modification method for electrochemical biosensors.
• This novel approach significantly reduces background noise, improving biosensing performance.
• The structure offers precise control over biomolecule adsorption/desorption and enhanced pH responsiveness.
• This represents a significant advancement in electrochemical biosensor technology, paving the way for more sensitive and reliable diagnostic tools.