PMMA isocyanate-modified digital discs as a support for oligonucleotide-based assays

Area of Science:

• Materials Science
• Biotechnology
• Surface Chemistry

Background:

• Developing functionalized surfaces is crucial for sensitive biomolecular detection.
• Polymethyl methacrylate (PMMA) offers a versatile platform for surface modification.
• Existing methods for surface derivatization can be complex or costly.

Purpose of the Study:

• To present a mild and effective chemical procedure for derivatizing PMMA with isocyanates.
• To demonstrate the utility of isocyanate-ended PMMA surfaces for oligonucleotide hybridization assays.
• To explore the application of this method for point-of-care diagnostics using modified compact discs (CDs).

Main Methods:

• Spin-coating a hydroxy-modified PMMA polymer onto rigid supports.
• Treating the coated support with (3-isocyanatopropyl)triethoxysilane to create isocyanate-ended PMMA.
• Performing oligonucleotide hybridization assays on the modified surface.
• Utilizing a CD player to detect enzymatic reactions (HRP-TMB) for signal amplification.

Main Results:

• The isocyanate derivatization of PMMA was achieved through a simple and highly effective chemical procedure.
• Oligonucleotide hybridization assays on the modified PMMA surface showed excellent performance, comparable to other materials like aminated PMMA, gold, and glass.
• Successful covalent attachment of aminated oligonucleotides onto a modified CD surface was demonstrated for DNA probe hybridization.
• Enzymatic reactions detected via a CD player confirmed the feasibility of the assay.

Conclusions:

• The developed method provides a straightforward and efficient way to create isocyanate-functionalized PMMA surfaces.
• This technique is suitable for sensitive DNA probe hybridization assays, even on low-cost platforms like CDs.
• The approach holds significant potential for developing portable, point-of-care diagnostic devices.