An electronic nose based on 2D group VI transition metal dichalcogenides/organic compounds sensor array

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Rapid detection of volatile organic compounds (VOCs) is crucial for various applications.
• Nanomaterials offer tunable properties for advanced sensor development.
• Group VI transition metal dichalcogenides (TMDs) are promising for chemical sensing.

Purpose of the Study:

• To develop novel 2D hybrid inorganic/organic TMD nanomaterials for VOC detection.
• To functionalize TMDs with organic compounds for water-assisted exfoliation and sensor fabrication.
• To evaluate the performance of these hybrid materials in an electronic nose (e-nose) for real-world applications.

Main Methods:

• Sonochemical exfoliation of Group VI TMDs (MoS2, WSe2, MoSe2) with organic compounds (ellagic acid, tannic acid, catechin, sodium cholate) in water.
• Fabrication of 16 distinct water-dispersed 2D hybrid TMD nanoflakes.
• Modification of quartz crystal microbalances (QCMs) with these hybrid materials to create an e-nose sensor array.
• Testing sensor responses to various VOCs (alcohols, terpenes, esters, aldehydes) and monitoring banana ripening.

Main Results:

• The 16 hybrid TMD sensors exhibited distinct responses to different VOCs, indicating synergistic effects.
• Sensors showed quantitative VOC detection (R² ≥ 0.978) with fast recovery (<100 s).
• High repeatability (RSD ≤ 9.3%), reproducibility (RSD ≤ 12.8%), and stability (RSD ≤ 14.6% over 3 months) were achieved.
• The e-nose successfully monitored banana aroma evolution during ripening.

Conclusions:

• Water-dispersed 2D hybrid TMDs functionalized with organic compounds are effective for sensitive and selective VOC detection.
• These sustainable nanomaterials offer significant potential for nano-bioelectronic applications, including food quality monitoring.
• The developed e-nose system provides a robust platform for real-time analysis of volatile compounds.