THz metasensors based on grating-patterned GaN/SrTiO₃ heterostructures for Sudan I trace detection

Area of Science:

• Materials Science
• Analytical Chemistry
• Food Science

Background:

• Food safety is a significant concern, with certain food additives potentially posing health risks like cancer.
• Accurate and sensitive detection methods are essential for identifying harmful contaminants in food products.

Purpose of the Study:

• To develop novel semiconductor-ultrasurface sensors for highly sensitive trace detection of Sudan I.
• To enhance the sensitivity and reliability of detecting Sudan I, a potentially carcinogenic food additive.

Main Methods:

• Proposed four novel semiconductor-ultrasurface sensor designs.
• Utilized gallium nitride (GaN)-based hypersurface sensors and grating-patterned GaN.
• Investigated strontium titanate/gallium nitride heterostructures for enhanced terahertz wave interaction.

Main Results:

• Achieved a low limit of detection (LOD) of 12.5 fg/mL for Sudan I using a GaN-based hypersurface sensor.
• Observed a significant enhancement in terahertz wave interaction with the analyte due to localized electric fields.
• Demonstrated an amplitude-frequency bi-dimensional spectral change and a maximum frequency shift of 297.54 GHz.
• Reported a maximum temperature change (ΔT%) of 12.91% for the strontium titanate/gallium nitride heterostructure.

Conclusions:

• The developed sensors offer significantly improved sensitivity for Sudan I detection compared to conventional methods.
• This research provides a novel application of terahertz technology for highly sensitive food safety analysis.
• The findings pave the way for advanced methods in detecting harmful food additives.