Blue emission-dominated NaYbF₄@NaYF₄:2%Ho@NaYF₄ upconversion nanoparticles for detecting ascorbic acid

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Upconversion nanoparticles (UCNPs) offer unique optical properties for sensing applications.
• Controlling the emission of UCNPs, particularly in the visible spectrum, is crucial for developing sensitive detection platforms.
• Ascorbic acid (AA) is an important biomarker, and sensitive detection methods are needed.

Purpose of the Study:

• To design and synthesize blue emission-dominated NaYbF4@NaYF4:2%Ho@NaYF4 (CSS) upconversion nanoparticles (UCNPs).
• To investigate the mechanism behind the enhanced blue emission of the CSS UCNPs.
• To develop a fluorescence resonance energy transfer (FRET)-based nanosensing platform using CSS UCNPs for the sensitive detection of ascorbic acid (AA).

Main Methods:

• Synthesis of NaYbF4@NaYF4:2%Ho@NaYF4 (CSS) UCNPs with a core-shell structure.
• Characterization of UCNP properties, including blue emission intensity and mechanisms.
• Development of a FRET-based sensing system utilizing CSS UCNPs as donors and MnO2 nanosheets as acceptors for AA detection.

Main Results:

• The CSS UCNPs exhibited significantly enhanced blue emission compared to control UCNPs.
• The enhanced blue emission was attributed to protected NaYbF4 core, spatial separation of Yb3+ and Ho3+, and an inert shell.
• A sensitive AA detection platform was established with a detection limit of 0.75 μM and a detection range of 0.5-100 μM.

Conclusions:

• The study successfully explored the blue emission mechanism of Ho3+ in UCNPs.
• A novel CSS/MnO2-based nanosensing platform was constructed for rapid and sensitive AA detection.
• The developed UCNPs and sensing platform show promising applications in biochemical sensing and detection.