A portable NELIBS-based paper sensor for on-site trace element analysis in sewage and soil

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Effective on-site elemental analysis of polluted water and soil is vital for agriculture and food safety.
• Traditional methods often require complex, time-consuming sample pretreatment, hindering rapid assessment.
• Nanoparticle-enhanced laser-induced breakdown spectroscopy (NELIBS) offers a promising solution for sensitive, rapid detection without pretreatment.

Purpose of the Study:

• To develop a paper-based sensor for rapid, on-site, multiplexed trace element detection.
• To utilize gold nanorods embedded in metal-organic frameworks (AuNRs@MOFs) for enhanced signal amplification in laser-induced breakdown spectroscopy (LIBS).
• To validate the sensor's performance in real-world environmental samples like sewage and soil.

Main Methods:

• Fabrication of a paper-based sensor incorporating AuNRs@MOFs.
• Application of laser-induced breakdown spectroscopy (LIBS) for elemental analysis.
• Comparison of sensor results with Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for accuracy assessment.

Main Results:

• The AuNRs@MOFs modified sensor demonstrated excellent linear response for trace copper (Cu) and chromium (Cr) detection.
• Achieved low detection limits for Cu and Cr in water (0.03 µg/L, 2.49 µg/L) and soil (0.145 mg/kg, 0.072 mg/kg).
• Sensor accuracy in real samples was comparable to the established ICP-MS method.

Conclusions:

• The developed paper-based NELIBS sensor enables efficient, on-site, multiplexed detection of heavy metals in complex environmental matrices.
• This technology significantly reduces sample preparation time and enhances detection sensitivity.
• The sensor presents a valuable tool for environmental protection initiatives and safeguarding food safety.