Surface-enhanced Raman scattering labeled nanoplastic models for reliable bio-nano interaction investigations

Nanoplastics (NPs) have attracted great attention as an emerging pollution. To date, their interaction with biological systems has been studied mostly by using fluorescent-labeled NPs, which suffered from serious drawbacks such as biological autofluorescence interference and false-positive results. Reliable optically labeled NP models are eagerly desired until now. Herein, a novel near-infrared (NIR) surface-enhanced Raman scattering (SERS) labeled NP model was proposed, which gained single-particle ultra-sensitivity, deep tissue detection, multiplex labeling ability, and anti-interference property. More importantly, the NP demonstrated satisfactory in vivo signal stability which completely prevented the positive-false problems. The advantages of the NPs enabled direct, dynamic in vivo behavior imaging study in living zebrafish embryo, adult zebrafish and green vegetable Brassica rapa. It was found for the first time that NPs entered blood circulation system of zebrafish larva via dermal uptake route, which only occurred in a short 48 h-window post-hatch. NPs widely distributed in roots, shoots and leaves of Brassica rapa seedlings germinating and growing in the NP-containing hydroponic culture. Different depths of one root showed varied adsorption capabilities towards NPs with fulvic acid, lipid and sodium dodecyl sulfate eco-coronas. This work provided an ideal tool for reliable bio-NP interaction study for a variety of organisms, which could promote the research of NPs.

Automated summary

A novel near-infrared surface-enhanced Raman scattering labeled nanoplastic model was proposed, showing high sensitivity, deep tissue detection, multiplex labeling ability, and anti-interference properties. The nanoparticles demonstrated the ability to enter the blood circulation system of zebrafish and distribute widely in the roots, shoots, and leaves of Brassica rapa seedlings. This work provides a reliable tool for studying bio-nanoplastics interactions and could advance nanoplastic research.