Microplastics and nanoplastics detection using flow cytometry: Challenges and methodological advances with...

Area of Science:

• Environmental Science
• Analytical Chemistry

Background:

• Flow cytometry (FC) is a powerful technique for quantifying microparticles and nanoparticles (>200 nm).
• FC has been adapted for environmental analysis of microplastics and nanoplastics (MNPs), utilizing Nile Red for enhanced detection.
• Traditional methods often miss smaller particles (<1 µm), highlighting FC's advantage in automated, sensitive detection.

Purpose of the Study:

• To review recent advancements in flow cytometry for microplastic and nanoplastic detection.
• To identify technical improvements and remaining metrological challenges in FC-based MNP analysis.
• To provide insights for refining FC methods for future environmental investigations.

Main Methods:

• Review of recent scientific literature on flow cytometry applications for MNP detection.
• Analysis of methodologies for enhancing MNP quantification accuracy, including dye solubilization techniques.
• Examination of automated detection capabilities of FC for particles under 1 µm.

Main Results:

• Nile Red significantly improves sensitivity and specificity in MNP detection via FC.
• Undissolved dye in aqueous media poses a challenge for accurate MNP quantification.
• Co-solvents, surfactants, pre-filtration, and pre-sonication are key strategies to overcome dye-related limitations.

Conclusions:

• Flow cytometry is a promising technique for sensitive and automated MNP detection in environmental samples.
• Addressing dye solubility issues is crucial for improving the metrological reliability of FC-based MNP quantification.
• Further refinement of FC methodologies is needed for comprehensive MNP analysis.