Adaptable DNA-Interactive Probe Proficient at Selective Turn-On Sensing for Al³⁺: Insight from the Crystal Structure,...

Area of Science:

• Coordination Chemistry
• Supramolecular Chemistry
• Fluorescence Spectroscopy

Background:

• Schiff base ligands are versatile in coordination chemistry.
• Excited-state-induced proton transfer (ESIPT) can quench fluorescence.
• Chelation-enhanced fluorescence (CHEF) offers a strategy for metal ion sensing.

Purpose of the Study:

• To synthesize and characterize a novel Schiff base ligand, H2NPV.
• To investigate the fluorescence response of H2NPV to metal ions.
• To explore the potential of H2NPV as a selective sensor for Al3+.

Main Methods:

• Single-crystal X-ray diffraction (XRD) for structural characterization.
• Spectroscopic techniques (UV-Vis, fluorescence) to study metal ion complexation.
• Theoretical calculations to understand coordination modes.
• Calorimetric methods for DNA binding studies.

Main Results:

• H2NPV exhibits weak fluorescence due to ESIPT.
• Complexation with Al3+ blocks ESIPT and induces CHEF, leading to 'turn-on' fluorescence.
• The probe H2NPV shows high selectivity for Al3+ over other metal ions.
• A detection limit of 1.70 μM for Al3+ was achieved.
• DNA binding studies suggest potential bioactivity.

Conclusions:

• H2NPV is an effective fluorescent probe for selective Al3+ detection.
• The mechanism involves blocking ESIPT and inducing CHEF.
• The ligand demonstrates potential for applications in molecular logic gates and bioassays.