Acridine-based complex as amino acid anion fluorescent sensor in aqueous solution

Area of Science:

• Chemical Sensors
• Fluorescence Spectroscopy
• Organic Synthesis

Background:

• Development of selective and sensitive fluorescence sensors is crucial for detecting metal ions and anions.
• Acridine derivatives offer promising photophysical properties for sensor applications.
• Alaninol ligands can provide specific binding sites for target analytes.

Purpose of the Study:

• To design and synthesize novel acridine-based fluorescence sensors incorporating alaninol ligands.
• To investigate the sensing capabilities of these compounds for copper(II) cations and amino acid anions.
• To explore the mechanism of fluorescence signaling and the potential for ratiometric detection.

Main Methods:

• Synthesis of acridine-based compounds L1 and D1 with alaninol ligands.
• Structural characterization using Infrared (IR) spectroscopy, Nuclear Magnetic Resonance ((1)H NMR, (13)C NMR), and Mass Spectrometry (MS).
• Fluorescence spectroscopy to study the interaction with Cu(2+) cations and amino acid anions in aqueous solution at physiological pH.

Main Results:

• Successful synthesis and characterization of acridine-based fluorescence sensors L1 and D1.
• L1 and D1 exhibit efficient ON-OFF selective fluorescence signaling for Cu(2+) cations via a ligand-to-metal binding mechanism.
• The L1-Cu(II) and D1-Cu(II) complexes function as reversible OFF-ON sensing ensembles for amino acid anions, enabling ratiometric detection.

Conclusions:

• Novel acridine-based fluorescence sensors with alaninol ligands have been developed.
• These sensors demonstrate selective and efficient detection of Cu(2+) and subsequent ratiometric sensing of amino acid anions.
• The developed sensing systems hold potential for applications in chemical sensing and biological analysis.