Efficient cyanide sensing using plasmonic Ag/Fe₃O₄ nanoparticles

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Environmental Science

Background:

• Cyanide detection is crucial for environmental monitoring and industrial safety.
• Existing cyanide sensors often lack the required sensitivity, selectivity, or broad linear range.
• Previous work established a silver/iron oxide nanoparticle (Ag/Fe3O4 NPs) probe for cyanide detection.

Purpose of the Study:

• To enhance a magnetic nanoparticle-based sensor for improved cyanide determination.
• To achieve a wider calibration range, higher precision, and selectivity for cyanide detection.
• To develop a robust and easily reproducible sensor system.

Main Methods:

• Synthesis of Ag/Fe3O4 NPs using a green preparation method.
• Characterization of NPs using powder X-ray diffraction (XRD), UV-Vis absorption spectroscopy, transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX).
• Detection of cyanide by simultaneously analyzing enhanced scattered light (Rayleigh signal) and fluorescence quenching, coupled with a method to mitigate interference.

Main Results:

• The improved sensor system demonstrates a significantly extended linear detection range from 1.0 nM to 160 μM (0.026 ng mL-1 to 4.16 μg mL-1), the widest reported to date.
• The method combines enhanced Rayleigh scattering and fluorescence quenching for accurate cyanide quantification.
• The sensor exhibits high selectivity and precision, effectively removing interference.

Conclusions:

• The enhanced Ag/Fe3O4 NP sensor provides a highly sensitive, selective, and precise method for cyanide determination.
• This technique offers the broadest linear assay range reported for cyanide detection.
• The developed sensor is practical for analyzing cyanide in real samples, advancing environmental and safety monitoring capabilities.