Pyrene-acylhydrazone-based Turn-on Fluorescent Probe for Highly Sensitive Detection Cu²⁺ and Application in...

Area of Science:

• Analytical Chemistry
• Biochemistry
• Materials Science

Background:

• Developing selective fluorescent probes for copper ions (Cu2+) is crucial for environmental and life science applications.
• Existing probes often lack the desired sensitivity, selectivity, or biocompatibility.
• Copper ions play vital roles in biological processes, but their dysregulation is linked to various diseases.

Purpose of the Study:

• To synthesize and characterize a novel "turn-on" fluorescent probe for sensitive and selective detection of Cu2+.
• To investigate the sensing mechanism and binding properties of the probe with Cu2+.
• To evaluate the probe's applicability for intracellular imaging of Cu2+ in live cells.

Main Methods:

• One-step condensation reaction for probe synthesis.
• Characterization using 1H NMR, 13C NMR, and HRMS.
• Fluorescence spectroscopy for selectivity and detection limit determination.
• Job's plot analysis and HRMS for binding stoichiometry.
• 1H NMR titration and FT-IR for binding model investigation.
• Cellular toxicity assays and live-cell imaging.

Main Results:

• A novel pyrene-acylhydrazone-based fluorescent probe (T) was successfully synthesized.
• Probe T demonstrated high selectivity and a low detection limit (0.304 nM) for Cu2+.
• The sensing mechanism involves dual PET-TICT pathways with a 1:1 binding stoichiometry.
• Probe T exhibited low cytotoxicity and good membrane permeability.
• Successful application in fluorescent imaging of intracellular Cu2+ in HT-22 cells.

Conclusions:

• The developed probe T is a highly selective and sensitive tool for Cu2+ detection.
• The probe's biocompatibility and cell-imaging capabilities make it valuable for biological studies.
• This work offers a promising platform for developing advanced fluorescent probes for metal ion sensing.