Highly Sensitive Ratiometric Fluorescent Sensor for Trinitrotoluene Based on the Inner Filter Effect between Gold...

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Environmental Science

Background:

• Trinitrotoluene (TNT) is a hazardous explosive requiring sensitive detection methods.
• Existing detection methods may lack sensitivity or simplicity.
• Nanoparticle-based assays offer potential for enhanced sensing capabilities.

Purpose of the Study:

• To develop a simple and highly sensitive ratiometric fluorescent assay for TNT detection.
• To utilize the inner filter effect (IFE) between gold nanoparticles (AuNPs) and ratiometric fluorescent nanoparticles (RFNs).
• To create a dual-mode detection system for improved analytical performance.

Main Methods:

• Fabrication of RFNs by incorporating green-emissive carbon dots (CDs) and red-emissive quantum dots (QDs) into silica spheres.
• Exploiting the IFE mechanism where AuNPs quench CDs in dispersion and QDs upon aggregation.
• Utilizing TNT-induced aggregation of AuNPs to modulate fluorescence signals for ratiometric detection.

Main Results:

• The assay demonstrated sensitive TNT detection over a range of 0.1 to 270 nM.
• A low detection limit of 0.029 nM was achieved for TNT.
• Successful application in real water and soil samples with high recoveries (95-103%) and low precision (<4.5%).

Conclusions:

• The developed ratiometric fluorescent sensor provides a sensitive and reliable method for TNT detection.
• The IFE-based approach enhances sensitivity compared to traditional colorimetric or UV-Vis methods.
• This work promotes the development of advanced dual-mode detection systems for environmental monitoring.