One-Pot Synthesis of Ce-Based Nanocomposites for Fluorescence and Colorimetric Dual-Mode Sensing Platform...

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Cerium-based nanomaterials are recognized for catalytic properties.
• Limited research exists on combining cerium's catalytic and photoluminescent functions.
• Developing multifunctional nanomaterials is crucial for advanced sensing applications.

Purpose of the Study:

• To synthesize CeO₂/CePO₄ nanocrystals with integrated catalytic and photoluminescent properties.
• To develop a dual-mode sensing platform for hydrogen peroxide (H₂O₂) detection.
• To enhance detection accuracy by utilizing complementary sensing mechanisms.

Main Methods:

• One-step synthesis of CeO₂/CePO₄ nanocrystals by adjusting the Ce/P molar ratio.
• Utilizing the catalase-like activity of CeO₂/CePO₄ for colorimetric H₂O₂ detection via TMB oxidation (absorbance at 652 nm).
• Employing the photoluminescence of CeO₂/CePO₄ for fluorescence-based H₂O₂ detection (emission at 338 nm) through fluorescence quenching.

Main Results:

• Successfully synthesized CeO₂/CePO₄ nanocrystals integrating enzyme-like activities and optical properties.
• Demonstrated a colorimetric assay for H₂O₂ based on CeO₂/CePO₄'s catalase activity.
• Established a fluorescence-based assay for H₂O₂ detection leveraging fluorescence quenching.
• Observed that H₂O₂ oxidizes Ce³⁺ to Ce⁴⁺, leading to fluorescence quenching.

Conclusions:

• CeO₂/CePO₄ nanocrystals offer a dual-mode sensing platform for H₂O_2}.
• The combined colorimetric and fluorescence detection modes provide mutually verifiable results.
• This dual-signal approach significantly improves the accuracy and reliability of H₂O₂ detection compared to single-mode probes.