Low-Temperature-Enhanced and Ultrasensitive Exhaled H₂S Gas Sensor Based on Cu₂O-CuFe₂O₄ Nanoarrays

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Hydrogen sulfide (H2S) is a crucial biomarker for various diseases.
• Developing sensitive and selective H2S sensors for noninvasive diagnosis is essential.
• Existing sensors often face challenges with sensitivity, selectivity, and operational stability.

Purpose of the Study:

• To fabricate a high-performance H2S sensor using a p-n type Cu2O-CuFe2O4 heterostructure.
• To investigate the sensing properties of the Cu2O-CuFe2O4 heterostructure nanowire arrays.
• To explore the potential of the sensor for detecting H2S in human breath for disease diagnosis.

Main Methods:

• Fabrication of Cu2O-CuFe2O4 heterostructure ordered nanowire arrays on silicon substrates via 2D electrodeposition in situ assembly.
• Characterization of the sensor's response to H2S at room temperature and low temperatures.
• Evaluation of sensor performance including sensitivity, selectivity, limit of detection (LOD), response time, and humidity resistance.

Main Results:

• The Cu2O-CuFe2O4 heterostructure sensor exhibited significantly enhanced H2S detection compared to Cu2O alone.
• Achieved a high response (234.5) with a low LOD (10 ppb) at room temperature.
• Demonstrated excellent selectivity, humidity resistance, and unique low-temperature-enhanced sensing capabilities.
• Successfully detected H2S in human oral exhaled breath samples.

Conclusions:

• The developed Cu2O-CuFe2O4 heterostructure sensor offers superior performance for H2S detection.
• The sensor shows great potential for noninvasive disease diagnosis through breath analysis.
• This work presents a promising approach for developing advanced room-temperature breath analysis sensors.