Probe-free negatively charged dual-emission NaYF₄:Er³⁺, Yb³⁺@SiO₂ sensor for sensitive Rhodamine B detection

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Rhodamine B (RhB) is an illicit synthetic dye in food, posing health risks.
• Existing detection methods may lack sensitivity or require complex procedures.
• Development of sensitive and selective sensors is crucial for food safety.

Purpose of the Study:

• To develop a probe-free, dual-emission sensor for Rhodamine B detection.
• To utilize a core-shell structure of NaYF4:Er3+, Yb3+ upconversion microparticles coated with silica (UCMPs@SiO2).
• To establish a ratiometric sensing mechanism for enhanced detection accuracy.

Main Methods:

• Synthesis of NaYF4:Er3+, Yb3+ upconversion microparticles via hydrothermal method.
• Coating with a silica shell using Stöber method for stability and dispersibility.
• Ratiometric detection based on the inner filter effect (IFE) on green emission by RhB.

Main Results:

• The UCMPs@SiO2 sensor demonstrated a low detection limit of 12.80 ng mL-1.
• A linear detection range from 0.30 to 0.001 ppm was achieved.
• The sensor exhibited high repeatability, anti-interference, and selectivity.

Conclusions:

• UCMPs@SiO2 offers a promising probe-free platform for sensitive food safety monitoring.
• The sensor provides a simple, environmentally benign, and versatile detection strategy.
• This approach can be extended for detecting other organic dyes and toxic pollutants.