Label-Free Detection of 2,4-Dinitrotoluene Using a Laser-Induced Graphene Based Chemiresistive Sensor

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Nitroaromatic explosives like 2,4-dinitrotoluene (DNT) pose significant security and environmental risks.
• Sensitive and selective detection methods are crucial for explosives identification.
• Existing detection technologies often face limitations in sensitivity, selectivity, or cost.

Purpose of the Study:

• To develop a label-free chemiresistive sensor for the rapid and sensitive detection of DNT.
• To utilize laser-induced graphene (LIG) fabricated on flexible substrates for sensor development.
• To evaluate the sensor's performance, including sensitivity, selectivity, and detection limits.

Main Methods:

• Fabrication of LIG films on polyimide substrates using a single-step laser writing process.
• Comprehensive characterization of LIG properties using SEM, XRD, Raman, FTIR, and XPS.
• Development and testing of a chemiresistive sensor based on the fabricated LIG films.
• Evaluation of sensor response, selectivity against interferents, and determination of the limit of detection (LOD).

Main Results:

• Porous, conductive multilayer graphene (approx. 5 layers) with low defect density was successfully fabricated.
• The LIG films exhibited uniform electrical conductivity (1545 S/m).
• The developed chemiresistive sensor demonstrated sensitive detection of DNT with an LOD of 2.4 × 10^-9 M and high selectivity against related compounds.

Conclusions:

• Laser-induced graphene (LIG) provides a scalable and cost-effective platform for flexible sensor fabrication.
• The developed LIG-based sensor offers a promising solution for selective and sensitive detection of nitroaromatic explosives.
• This technology has significant potential for applications in security and environmental monitoring.