A Dual-Emission Probe Based on Silicon Nanoparticles and Rhodamine B for Ratiometric Fluorescence/Colorimetric...

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Environmental Science

Background:

• Silicon nanoparticles (SiNPs) offer unique optical properties.
• Developing sensitive detection methods for environmental pollutants like methyl parathion is crucial.

Purpose of the Study:

• To synthesize blue fluorescent silicon nanoparticles (SiNPs).
• To create an enzyme-free ratiometric fluorescence probe by combining SiNPs with rhodamine B (RhB).
• To establish a dual-mode (fluorescence/colorimetric) detection system for methyl parathion.

Main Methods:

• Hydrothermal synthesis of SiNPs using 3-(aminopropyl)triethoxysilane (APTES) and L-cysteine.
• Formation of the SiNPs@RhB probe for ratiometric fluorescence detection.
• Development of a colorimetric detection method based on methyl parathion hydrolysis.
• Analysis of real samples including lake water, soil, gongju, and sanqi powder.

Main Results:

• The SiNPs@RhB probe exhibited dual emission peaks at 457 nm and 565 nm under 383 nm excitation.
• A ratiometric fluorescence method detected methyl parathion with a linear range of 0.1-100 µmol/L and a detection limit of 0.03 µmol/L.
• A colorimetric method detected methyl parathion with a linear range of 0.1-200 µmol/L and a detection limit of 0.03 µmol/L.
• The probe showed color changes from pink to orange with increasing methyl parathion concentration.

Conclusions:

• The developed SiNPs@RhB probe provides a sensitive and effective dual-mode detection system for methyl parathion.
• The methods demonstrated satisfactory recoveries in real sample analysis, indicating practical applicability.
• This approach offers a promising tool for environmental monitoring and food safety.