Detection of explosives in a dynamic marine environment using a moored TNT immunosensor

Area of Science:

• Environmental Science
• Analytical Chemistry
• Sensor Technology

Background:

• Explosives like 2,4,6-trinitrotoluene (TNT) pose environmental risks, necessitating effective marine monitoring.
• Existing methods for detecting TNT in marine environments are often limited in duration and real-time capability.
• Microfluidic immunosensors offer potential for sensitive and portable detection of chemical contaminants.

Purpose of the Study:

• To conduct a field demonstration and assess the longevity of an anti-TNT microfluidic immunosensor for long-term marine monitoring.
• To evaluate the sensor's performance in detecting trace levels of TNT under dynamic oceanic conditions.
• To establish a robust system for continuous, real-time monitoring of TNT in seawater.

Main Methods:

• Fabrication of a poly(methylmethacrylate) (PMMA) microfluidic device with 39 parallel microchannels.
• Chemical functionalization of microchannels with high-affinity anti-TNT antibodies.
• Utilized a displacement-based assay with synthesized fluorescence reporter complexes for TNT identification.
• Configured the immunosensor on a submersible frame with a plume generator for intermittent sampling (>18 h).

Main Results:

• The anti-TNT microfluidic immunosensor successfully detected trace levels of TNT in natural seawater.
• Detection was achieved over an extended period (>18 hours) under varying current and tidal conditions.
• The system demonstrated capability for overnight operation with data monitoring via a web interface.

Conclusions:

• The developed microfluidic immunosensor system is effective for long-term, in-situ monitoring of TNT in marine environments.
• The sensor demonstrates robustness and reliability for detecting explosive contaminants under challenging oceanic conditions.
• This technology provides a valuable tool for environmental risk assessment and remediation strategies in marine ecosystems.