Detection of microplastics through an optical sensor array using nano-graphene oxide and fluorophore conjugates

Area of Science:

• Environmental Science
• Materials Science
• Analytical Chemistry

Background:

• Microplastics (MPs) are pervasive environmental pollutants originating from degraded synthetic materials.
• MPs contaminate drinking water, food, soil, and organisms, necessitating advanced detection methods.
• Current detection techniques struggle with classifying diverse MP types in complex matrices.

Purpose of the Study:

• To develop a cost-effective sensor array for discriminating various microplastic types.
• To utilize nano-graphene oxide (nGO) as a receptor for MP detection and classification.
• To assess the sensor's efficacy in real-world water samples and identify MP leachates.

Main Methods:

• A two-step signal output strategy involving organic fluorophores and nano-graphene oxide (nGO).
• Fabrication of a sensor array capable of modulating fluorescence responses from MPs.
• Discrimination of six different MP types at low concentrations (A260 nm = 0.025).

Main Results:

• The sensor array successfully differentiated six types of microplastics.
• Effective MP detection was demonstrated in river, lake, and tap water, even with environmental interferents.
• The system detected microplastic leachates in water stored in plastic containers and in packaged bottled water.

Conclusions:

• Nano-graphene oxide serves as a stable and effective receptor for microplastic discrimination.
• The developed sensor array offers a promising tool for verifying water quality by detecting microplastic contamination.
• This technology has implications for environmental monitoring and public health protection against micropollutants.