Two-photon fluorescent Bombyx mori silk by molecular recognition functionalization.

Area of Science:

• Biomaterials Science
• Fluorescence Imaging
• Molecular Engineering

Background:

• Two-photon fluorescence (TPF) microscopy offers advantages for deep tissue imaging.
• Silkworm silk fibroin is a biocompatible material with potential for bioimaging scaffolds.
• Functionalizing silk fibers can enhance their optical properties for advanced applications.

Purpose of the Study:

• To functionalize Bombyx mori silk fibers with a nitrofluorene derivative for enhanced TPF bioimaging.
• To investigate the role of molecular recognition in improving TPF quantum yield.
• To develop TPF silk scaffolds for high-quality cellular imaging.

Main Methods:

• Silk fibroin fibers were functionalized using 2,7-bis((E)-4-((E)-4-nitrostyryl)styryl)-9,9-dioctyl-9H-fluorene (NF).
• TPF quantum yield was measured and compared between functionalized silk and solid-state NF.
• Comparative studies were conducted using non-recognizing molecules (MF1, MF2).
• TPF silk scaffolds were fabricated and utilized for cell imaging.

Main Results:

• NF functionalization significantly enhanced TPF quantum yield by 350% due to molecular recognition with silk fibroin.
• Non-functionalized silk or silk with non-recognizing molecules showed minimal TPF enhancement.
• High-quality TPF imaging of NF within cell cultures was successfully achieved using the developed silk scaffolds.

Conclusions:

• Molecular recognition between NF and silk fibroin is crucial for boosting TPF quantum yield.
• TPF-functionalized silk fibers serve as effective scaffolds for advanced bioimaging.
• This approach holds significant promise for biomedical applications requiring high-resolution cellular imaging.