HSA-based phosphorescent probe for two-photon in vitro visualization

Area of Science:

• Materials Science
• Biomedical Imaging
• Nanotechnology

Background:

• Two-photon microscopy offers superior resolution and penetration compared to conventional methods.
• Developing effective two-photon probes is crucial for advancing multiphoton bioimaging.
• Existing probes often face limitations in excitation range and signal intensity.

Purpose of the Study:

• To develop and characterize a novel phosphorescent probe for two-photon microscopy.
• To evaluate the probe's performance in bioimaging applications.
• To demonstrate the probe's utility for visualizing biological structures with enhanced optical properties.

Main Methods:

• Synthesis of a phosphorescent non-covalent adduct: human serum albumin and an Au-Ag alkynyl-diphosphine complex ([Au14Ag4(C2Ph)12(PPh2C6H4PPh2)6][PF6]4).
• Characterization of the probe's two-photon-induced luminescence (TPE) properties, including cross-section (δTPE) and excitation wavelength range.
• Application of the probe in two-photon confocal microscopy for imaging glioma C6 cells and various tissues.

Main Results:

• The synthesized probe exhibits a high two-photon luminescence cross-section (δTPE) up to 38 GM.
• The probe demonstrates efficient luminescence within a broad near-infrared excitation range (700-800 nm).
• Successful visualization of glioma C6 cells and diverse tissues was achieved using two-photon confocal microscopy in planar and z-stacking modes.

Conclusions:

• The developed human serum albumin-based Au-Ag complex is a promising phosphorescent probe for multiphoton bioimaging.
• Its broad excitation range allows for optimized signal-to-background ratios by adjusting the excitation wavelength.
• The probe facilitates high-resolution imaging of biological samples, advancing the capabilities of two-photon microscopy.