Visible-light-sensitive microrobots using H2O as fuel for highly efficient capture and precise detection of nanoplastics

• Published in: Journal of hazardous materials 2024-11, Vol.479, p.135731, Article 135731
• Main Authors: Geng, Zhiqin, Deng, Tangtang, Gu, Bohan, Qian, Xinting, Li, Rui, Duan, Linfen, Li, Junyang, Han, Weiqing, Qu, Lulu, Wei, Kajia
• Format: Article
• Language: English
• Subjects: Dynamic capture; Machine learning; Microrobots; Nanoplastics
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.135731

Nanoplastics, which are small plastic particles resulting from the decomposition of plastic waste, can accumulate and adsorb toxic chemicals in aquatic environments, leading to detrimental effects on the environment and human health. Consequently, there is an urgent demand for the development of an efficient method to accurately quantify and effectively remove nanoplastics. Here, we prepared a novel "cage-like" microrobot for effective dynamic capture and highly sensitive surface-enhanced Raman scattering detection of nanoplastics in situ. The microrobot utilizes water as fuel under visible light and achieves efficient capture of nanoplastics within 2 min on the basis of the stacking structure between layers and electrostatic action. The microrobot could be recovered by an external magnetic field, and the SERS activity was greatly enhanced through the coupling of multilayer hot spots, with a detection limit of 1.27 μg/mL. We built a simple device to demonstrate the feasibility of the microrobot strategy of capturing plastic in real wastewater and further extended this technology to single-use plastic cups in everyday life. Moreover, many different types of plastic spectra can also be quickly distinguished when combined with machine learning. This work provides new ideas for improving the dynamic capture and effective monitoring of nanoplastics. [Display omitted] •"cage-like" microrobots chase and guide the collection of nanoplastics through unique multi-layer stacking via optical drive.•Annular Fe3O4 assembly modified with Au NPs allows microrobots recovery and in-situ SERS detection.•The microrobots proved the release of plastic cup particles under adverse conditions, highlighting the environmental impact.•Machine learning algorithm realizes multi-type nanoplastic identification, providing new ideas for effective monitoring.