Conjugated Polymer Nanoparticles as a Universal High-Affinity Probe for the Selective Detection of Microplastics

Area of Science:

• Environmental Science
• Materials Science
• Analytical Chemistry

Background:

• Microplastic (MP) pollution is a significant global environmental challenge.
• Current MP detection methods lack sensitivity and selectivity, hindering effective monitoring and mitigation.
• There is a need for advanced materials that can selectively identify and quantify MPs in diverse environmental matrices.

Purpose of the Study:

• To design and synthesize novel conjugated polymer nanoparticles (CPNs) for selective microplastic detection.
• To investigate the binding affinity and selectivity of these CPNs for various types of MPs.
• To establish a new platform for sensitive MP detection and potential mitigation strategies.

Main Methods:

• Synthesis of fluorescent diketopyrrolopyrrole nanoparticles via nanoprecipitation.
• Incorporation of hyaluronic acid for enhanced affinity to various plastic polymers.
• Characterization using fluorescence spectroscopy, microscopy, nanoparticle tracking analysis, and computational studies.
• Evaluation of CPNs in heterogeneous environmental samples like soil debris.

Main Results:

• CPNs exhibited high fluorescence in the presence of abundant MPs, with picomolar binding constants.
• Demonstrated strong affinity for a broad range of plastics due to cooperative supramolecular and topographical effects.
• Showed high selectivity for MPs, enabling detection in complex samples with organic contaminants.
• Advanced microscopy and in silico studies elucidated the mechanisms of binding.

Conclusions:

• The developed CPNs represent a promising advancement in selective microplastic detection technology.
• This novel material design offers a potential platform for developing point-of-collection MP detection devices.
• The findings open new avenues for mitigating microplastic pollution through tailored material development.