Efficient Chemical Surface Modification Protocol on SiO₂ Transducers Applied to MMP9 Biosensing.

Area of Science:

• Biomedical Engineering
• Materials Science
• Analytical Chemistry

Background:

• Bioreceptor immobilization (biofunctionalization) is a critical bottleneck for developing sensitive label-free biosensors.
• Existing methods often lack efficiency and reproducibility, limiting biosensor performance.
• SiO2 optical sensing transducers require robust biofunctionalization for optimal function.

Purpose of the Study:

• To develop a unique and efficient biofunctionalization protocol for SiO2 optical sensing transducers.
• To improve the sensitivity, stability, and reproducibility of label-free biosensors.
• To demonstrate the effectiveness of a novel silane chemistry approach for biofunctionalization.

Main Methods:

• Chemical surface modification of SiO2 using a unique silane compound, (3-Ethoxydimethylsilyl)propylamine (APDMS).
• Surface characterization using Contact Angle (CA), X-ray Photoelectron Spectroscopy (XPS), ellipsometry, and fluorescence microscopy.
• Application of functionalized SiO2 surfaces as optical transducers for label-free biosensing of matrix metalloproteinase 9 (MMP9).

Main Results:

• The APDMS-based silane chemistry created ordered monolayers, minimizing fouling events.
• Surface characterization confirmed the protocol's reproducibility and stability.
• The developed SiO2 surfaces demonstrated suitability for label-free biosensing of MMP9.

Conclusions:

• The novel biofunctionalization protocol using APDMS is reproducible, stable, and effective for SiO2 optical sensing transducers.
• This approach overcomes limitations of classical biofunctionalization methods.
• The protocol enhances the potential for developing high-performance label-free biosensors.