A highly selective and sensitive ICT-based Cu²⁺ fluorescent probe and its application in bioimaging.

Area of Science:

• Analytical Chemistry
• Environmental Science
• Biochemistry

Background:

• Copper ions (Cu²⁺) are essential but toxic in excess.
• Developing specific and sensitive probes for Cu²⁺ is crucial for biological and environmental studies.

Purpose of the Study:

• To construct a "Turn-Off" fluorescent probe (DPAP) for specific Cu²⁺ detection.
• To evaluate DPAP's performance for environmental and biological applications.

Main Methods:

• Synthesis and characterization of the DPAP probe.
• Fluorescence spectroscopy for Cu²⁺ detection.
• Human high-resolution mass spectrometry (HRMS), proton nuclear magnetic resonance (¹H NMR), and density functional theory (DFT) calculations for mechanism confirmation.
• In vitro and in vivo imaging in HeLa cells and zebrafish.

Main Results:

• DPAP demonstrated a large Stokes shift (120 nm), rapid response (1 min), and a low detection limit (15.2 nM).
• The probe exhibited low toxicity and good cell permeability.
• Cu²⁺ quenched DPAP fluorescence by inhibiting intramolecular charge transfer.
• DPAP successfully detected Cu²⁺ in environmental water samples and visualized its distribution in cells and zebrafish.

Conclusions:

• DPAP is a highly effective fluorescent probe for specific Cu²⁺ detection.
• The probe shows significant potential for real-time monitoring of copper in environmental and biological systems.
• This research provides theoretical support for studying the environmental behavior of heavy metal ions.