Functional fluorinated modifications on a polyelectrolyte coated polydimethylsiloxane substrate for fabricating...

Area of Science:

• Materials Science
• Biotechnology
• Surface Chemistry

Background:

• Fluorinated compounds offer desirable hydrophobic and nonstick properties for biochip coatings.
• Existing biochip surfaces often suffer from nonspecific protein binding and sample wetting issues.

Purpose of the Study:

• To develop a novel fluorinated coating for polydimethylsiloxane (PDMS) biochips.
• To create a functional surface that captures antibodies while resisting nonspecific binding.
• To improve the sensitivity and simplicity of on-chip bioassays.

Main Methods:

• Copolymerization of 1H,1H,2H-perfluoro-1-decene (FD) with acrylic acid (AA).
• Bonding of the FD/AA copolymer with protein G onto a polyelectrolyte-coated PDMS surface.
• Characterization using contact angle measurements and spectroscopic analysis.
• Application in antibody microarrays for detecting ERα in MCF-7 cells.

Main Results:

• The modified PDMS surface maintained hydrophobicity and resisted nonspecific protein binding.
• Aqueous sample droplets (4 μL) remained stable without spreading or drying.
• FD/AA copolymerization formed a dense, homogeneous multilayer with significant fluorine coverage (35.4%).
• Protein G covalently bound to the surface at a density of 0.24 μg/mm(2).
• Fluorinated coatings demonstrated six times higher sensitivity than PEG coatings in bioassays, eliminating the need for blocking agents.
• Accurate determination of ERα concentration in MCF-7 cells was achieved.

Conclusions:

• Fluorinated coatings provide excellent resistance to wetting, nonspecific binding, and contamination.
• This functionalized surface is ideal for sensitive and straightforward on-chip bioassays.
• The developed PDMS antibody microarrays offer a promising platform for accurate cellular analysis.