A simple 'turn-on' fluorescence chemosensor for Al(iii) detection in aqueous solution and solid matrix

Area of Science:

• Analytical Chemistry
• Materials Science
• Chemical Sensing

Background:

• Aluminum ion (Al(iii)) detection is crucial in environmental and biological monitoring.
• Existing methods for Al(iii) detection can be complex, time-consuming, or lack sensitivity.
• Development of simple, rapid, and selective fluorescent chemosensors is highly desirable.

Purpose of the Study:

• To develop a novel, simple, and highly selective fluorescence chemosensor for Al(iii) detection.
• To investigate the sensing mechanism and performance characteristics of the developed sensor.
• To demonstrate the practical application of the sensor for Al(iii) detection on a solid matrix.

Main Methods:

• A one-step synthesis of the FHS-OH Schiff base fluorescence chemosensor.
• Fluorescence spectroscopy was employed to study the response of FHS-OH to Al(iii).
• Mechanism studies involved analyzing binding stoichiometry, pH effects, and fluorescence properties, including aggregation-induced emission (AIE).

Main Results:

• The FHS-OH chemosensor exhibited a fast and highly selective 'turn-on' fluorescence response to Al(iii).
• A low detection limit of 63 nmol L⁻¹ and a linear range of 0.0–20.0 μmol L⁻¹ were achieved.
• The sensor demonstrated a visible color change from green to bright blue upon Al(iii) addition, facilitating naked-eye detection on test paper.

Conclusions:

• The developed FHS-OH Schiff base chemosensor offers a simple, rapid, and sensitive method for Al(iii) detection.
• The sensor's mechanism involves limited C=N isomerization and PET processes, coupled with AIE characteristics.
• The successful application on test paper highlights its potential for practical, real-time Al(iii) monitoring.