Ratiometric fluorescence sensor for Cu²⁺ detection based on opposite responses of two fluorescence reagents to SBA-15...

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Heavy metal ion detection is a global environmental concern.
• Copper ions (Cu²⁺) are crucial in physiological processes, necessitating sensitive detection methods.
• Existing methods for Cu²⁺ detection often lack specificity or sensitivity.

Purpose of the Study:

• To design and fabricate a dual-emission ratiometric fluorescence sensing platform for the specific detection of Cu²⁺.
• To achieve high sensitivity, selectivity, and photobleaching resistance in Cu²⁺ sensing.
• To develop a rapid and accurate method for quantifying Cu²⁺ in practical samples.

Main Methods:

• Fabrication of a ratiometric fluorescence sensor using SBA-15-grafted 2-naphthalenemethanol group (2-NM) as a reference and zinc sulfide quantum dots (ZnS QDs) as a reporter.
• Investigating the fluorescence response of the sensor to various metal ions, with a focus on Cu²⁺.
• Evaluating the sensor's sensitivity, linear range, detection limit, and response time for Cu²⁺ detection.

Main Results:

• The sensor exhibited a 5-fold fluorescence intensity change upon addition of Cu²⁺, indicating high sensitivity.
• The fluorescence intensity of 2-NM remained stable, while ZnS QDs showed a strong response specifically to Cu²⁺.
• A wide linear detection range (1.0–10.0 µmol L^-1) with a low detection limit (37.5 nM) and rapid response time (3 min) was achieved.

Conclusions:

• The developed dual-emission ratiometric fluorescence sensor provides a highly sensitive and selective method for Cu²⁺ detection.
• The sensor demonstrates excellent photobleaching resistance and good biocompatibility, suitable for practical sample analysis.
• This strategy offers a convenient system for monitoring various metal ions in biological activity.