A scanning near-field optical microscope approach to biomolecule patterning.

Area of Science:

• Photochemistry
• Biomaterials Science
• Nanotechnology

Background:

• Advancements in biosensors and biomaterials require precise surface modification techniques.
• Scanning near-field optical microscopy (SNOM) offers high-resolution optical manipulation.
• Photochemistry provides a versatile tool for molecular activation and immobilization.

Purpose of the Study:

• To investigate near-field photochemistry for future biosensor and biomaterial applications.
• To demonstrate direct photoactivation using SNOM.
• To achieve controlled biopatterning of surfaces with submicrometer resolution.

Main Methods:

• Utilized scanning near-field optical microscopy (SNOM) for photochemical investigations.
• Employed photoresist for demonstrating direct near-field-induced photoactivation.
• Performed photoimmobilization of maleimidoaryldiazirine and bovine serum albumin on various substrates.
• Characterized patterned surfaces using atomic force microscopy (AFM), time-of-flight secondary ion mass spectroscopy (ToF-SIMS), and near-field fluorescence microscopy.

Main Results:

• Successfully demonstrated direct photoactivation of standard photoresist using near-field light.
• Achieved photoimmobilization of maleimidoaryldiazirine on silicon and bovine serum albumin on glass substrates.
• Obtained controlled surface biopatterns with feature sizes in the submicrometer range.
• Confirmed pattern fidelity and composition using AFM, ToF-SIMS, and fluorescence microscopy.

Conclusions:

• Near-field photochemistry is a viable technique for high-resolution surface patterning.
• This method enables controlled immobilization of biomolecules for advanced applications.
• The demonstrated approach facilitates the development of next-generation biosensors and biomaterials.