Photoluminescent Ozone Sensor with Enhanced Sensitivity by Using CdSe/ZnS Quantum Dots Modified with Gold and...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Quantum dots (QDs) are semiconductor nanocrystals with tunable optical properties.
• Ozone (O3) is a reactive gas with significant environmental and health impacts.
• Developing sensitive and selective gas sensors is crucial for environmental monitoring.

Purpose of the Study:

• To develop and characterize photoluminescence-based ozone sensors using composite films.
• To investigate the role of noble metals (gold, platinum) in enhancing QD-based ozone sensing.
• To evaluate the sensitivity, reversibility, and response time of the developed sensor films.

Main Methods:

• Fabrication of composite films containing CdSe/ZnS core-shell quantum dots and noble metals (Au, Pt).
• Measurement of photoluminescence intensity changes in response to varying ozone concentrations (ppm levels) at ambient conditions (25°C, atmospheric pressure).
• Assessment of sensor recovery kinetics after ozone exposure.

Main Results:

• Composite films exhibited reversible photoluminescence changes upon exposure to ozone.
• The presence of gold and platinum significantly enhanced the sensing efficiency compared to QD-only films.
• Sensitivities to 0.5 ppm ozone were 27% (Au) and 43% (Pt), with no saturation up to 200 ppm.
• Noble metal-QD composites showed faster photoluminescence recovery after ozone removal.

Conclusions:

• Gold- and platinum-conjugated quantum dot films are effective for reversible and highly sensitive ozone detection.
• These composite films serve as promising sensor modules for ozone monitoring under ambient conditions.
• The enhanced sensitivity and rapid recovery highlight the potential of nanomaterial composites in gas sensing technology.