Ultrasensitive In₂O₃-Based Nanoflakes for Lung Cancer Diagnosis and the Sensing Mechanism Investigated by Operando...

Area of Science:

• Materials Science and Nanotechnology
• Chemical Sensing
• Biomedical Engineering

Background:

• Rapid gas sensing is crucial for industrial, smart living, and medical applications.
• Accurate detection of biomarkers like isoprene in breath is vital for early disease diagnosis, particularly lung cancer.
• Existing sensors often lack the required sensitivity, selectivity, or humidity resistance for clinical breath analysis.

Purpose of the Study:

• To develop a novel Pt@InNiO nanoflake-based gas sensor for highly sensitive and selective isoprene detection.
• To investigate the sensing mechanism behind the sensor's performance.
• To evaluate the sensor's efficacy in a portable device for noninvasive lung cancer screening via breath analysis.

Main Methods:

• Fabrication of Pt@InNiO nanoflakes.
• Construction of an *operando* DRIFTS-Raman cell coupled with electrical measurements to study the sensing mechanism.
• Integration of the sensor into a miniaturized portable electronic device for clinical testing.

Main Results:

• Achieved an exceptionally low limit of detection (LOD) of 2 ppb for isoprene, the lowest reported to date.
• Demonstrated high selectivity and remarkable anti-humidity capacity, crucial for breath analysis.
• Identified that Pt nanoclusters activate isoprene, while nanoflake morphology enhances adsorption and electron interaction; a p-n junction provides humidity resistance.

Conclusions:

• The Pt@InNiO nanoflake sensor offers ultrasensitive and selective isoprene detection with excellent humidity resistance.
• The developed sensor successfully distinguishes lung cancer patients from healthy individuals using breath analysis.
• This work presents a breakthrough in low-cost, noninvasive cancer screening and advances rational design of gas sensing materials.