A Fluorescence Sensor for Pb²⁺ Detection Based on Liquid Crystals and Aggregation-Induced Emission Luminogens

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Heavy metals, particularly lead ions (Pb2+), are significant environmental contaminants with adverse health effects.
• Existing lead ion detection methods are often time-consuming, require complex sample preparation, and involve expensive equipment, limiting real-time applications.

Purpose of the Study:

• To develop a novel, sensitive, selective, and cost-effective fluorescence sensor for detecting lead ions (Pb2+).
• To overcome the limitations of existing detection technologies for real-time environmental and biological monitoring.

Main Methods:

• Development of a fluorescence sensor utilizing liquid crystals doped with an aggregation-induced emission luminogen.
• Mechanism based on DNAzyme-induced catalytic cleavage, causing disturbance in liquid crystal configuration and altering fluorescence intensity in the presence of Pb2+.
• Characterization of sensor performance including detection limit, selectivity, and detection range.

Main Results:

• Achieved a low detection limit of 0.65 nM for Pb2+, significantly lower than previously reported optical sensors.
• Demonstrated a broad detection range from 20 nM to 100 μM.
• Exhibited high selectivity for lead ions over other metal ions.

Conclusions:

• The developed liquid crystal-based fluorescence sensor provides a highly sensitive, selective, simple, and low-cost strategy for Pb2+ detection.
• This approach has potential applications in chemical and biological fields for real-time monitoring.
• The sensor design offers a promising platform for detecting other heavy metal ions or biomacromolecules by modifying the decorated molecules.