Smartphone-Assisted Sensing of Trinitrotoluene by Optical Array.

Area of Science:

• Materials Science
• Analytical Chemistry
• Sensor Technology

Background:

• Conventional methods for explosive detection can be slow and require specialized equipment.
• There is a need for rapid, sensitive, and field-deployable detection systems for explosives like trinitrotoluene (TNT).

Purpose of the Study:

• To design and fabricate a novel array-based sensor for sensitive TNT detection.
• To develop a portable sensor system utilizing a smartphone as a detector for real-world applications.
• To evaluate the sensor's selectivity, linearity, and detection range for TNT.

Main Methods:

• Fabrication of an optical array sensor incorporating functionalized Carbon Dots, Bodipy, and Naphthalimide fluorescent probes.
• Utilizing fluorescence titrations to study probe-TNT interactions in solution.
• Testing the solid-state sensor device for selectivity and linearity against TNT concentration.
• Employing a smartphone as a detector for the optical array sensor.

Main Results:

• The sensor exhibits high fluorescence emissions and sensitivity for low concentrations of TNT.
• Demonstrated high selectivity for TNT over other explosives and nitrogen-based analytes.
• Achieved a TNT detection range from 98 ng to 985 μg.
• Each probe showed a distinct response to varying TNT concentrations, enabling quantitative analysis.

Conclusions:

• The developed array sensor, integrated with a smartphone, represents a significant advancement in portable TNT detection.
• The sensor's high sensitivity, selectivity, and field-deployability make it suitable for rapid diagnosis and field applications.
• This technology empowers non-specialist operators for immediate threat assessment and expert consultation.