A rapid-screening approach to detect and quantify microplastics based on fluorescent tagging with Nile Red

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Microplastic pollution is a growing global concern, necessitating sensitive and efficient detection methods.
• Current analytical techniques for microplastic identification can be time-consuming and require specialized equipment.

Purpose of the Study:

• To develop a cost-effective and accessible method for microplastic analysis.
• To enable the detection and quantification of microplastics in environmental matrices.
• To explore the potential of Nile Red staining for microplastic characterization.

Main Methods:

• Selective fluorescent staining of microplastics using Nile Red (NR).
• Density-based extraction and filtration for sample preparation.
• Image analysis of fluorescent particles captured via photography with an orange filter.
• Cross-validation with infrared (IR) microscopy.

Main Results:

• The Nile Red staining method successfully identified and counted microplastics in marine sediment samples.
• Fluorescent particles detected by NR staining corresponded with particles identified by IR microscopy.
• The method is capable of detecting microplastic particles down to a few micrometres in size.

Conclusions:

• Nile Red staining offers a viable and sensitive approach for microplastic detection and quantification.
• The solvatochromic properties of Nile Red may allow for further characterization of microplastic surface properties.
• This method provides a valuable tool for environmental monitoring of microplastic pollution.