Isopropanol sensor based on sprayed In₂S₃ thin film using linear discriminant analysis for real-time selectivity.

Area of Science:

• Materials Science
• Chemical Sensors
• Biomarker Detection

Background:

• Metal sulfides are promising for sensitive gas detection.
• Isopropanol is a volatile organic compound (VOC) and a potential lung cancer biomarker.
• Developing selective sensors for biomarkers like isopropanol is crucial for early disease diagnosis.

Purpose of the Study:

• To investigate the gas sensing performance of indium sulfide (In2S3) for isopropanol detection.
• To fabricate and characterize In2S3 thin films for sensor applications.
• To assess the sensor's sensitivity, stability, and selectivity towards isopropanol.

Main Methods:

• Fabrication of In2S3 thin films using spray pyrolysis.
• Structural and morphological characterization using XRD, MEB, AFM, and TEM.
• Gas sensing measurements of isopropanol vapor at various temperatures.
• Application of linear discriminant analysis (LDA) for selective analyte recognition.

Main Results:

• The In2S3 sensor exhibited high sensitivity (0.034 ppm-1) and stability over three weeks.
• A limit of detection (LOD) of 162 ppb for isopropanol was achieved.
• While cross-responses to other VOCs were observed, LDA enabled specific isopropanol identification.

Conclusions:

• In2S3 is a promising material for developing sensitive and stable isopropanol sensors.
• The developed sensor shows potential for detecting isopropanol as a lung cancer biomarker.
• Advanced data analysis techniques like LDA are effective for enhancing sensor selectivity.