A two-photon probe for Al(3+) in aqueous solution and its application in bioimaging

Area of Science:

• Analytical Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Fluorescence sensors are crucial for detecting metal ions.
• Two-photon (TP) absorption offers advantages for bioimaging due to deeper penetration and reduced phototoxicity.
• Developing selective and sensitive probes for aluminum ions (Al3+) is important for biological and environmental monitoring.

Purpose of the Study:

• To develop and characterize a salicylimine-based fluorescence probe (L) for Al3+ detection.
• To investigate the probe's sensing mechanism and stoichiometric ratio with Al3+.
• To evaluate the probe's applicability for in vitro and in vivo imaging of Al3+.

Main Methods:

• Synthesis and characterization of salicylimine probe L.
• One-photon (OP) and two-photon (TP) fluorescence spectroscopy.
• UV-Vis titration and fluorescence titration experiments.
• Job's plot analysis for stoichiometry determination.
• 1H NMR spectroscopy for mechanism elucidation.
• Cellular and tissue imaging studies.

Main Results:

• Probe L exhibited selective turn-on fluorescence response for Al3+ in aqueous solution.
• The stoichiometric ratio of L to Al3+ was determined to be 1:1.
• The probe demonstrated a low detection limit of 5.2×10(-9)M.
• Successful in vitro and in vivo imaging of Al3+ in live cells and tissues using TP fluorescence microscopy was achieved.
• The probe showed low autofluorescence and cytotoxicity.

Conclusions:

• Salicylimine probe L is a highly selective and sensitive sensor for Al3+.
• The probe's TP absorption properties facilitate effective bioimaging applications.
• This probe offers a novel and reliable method for Al3+ detection in biological samples.