Liu Yin, Li Jie, Parakhonskiy Bogdan V, Hoogenboom Richard, Skirtach Andre, De Neve Stefaan
Department of Environment, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium.
Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent Belgium.
J Hazard Mater. 2024 Jan 15;462:132785. doi: 10.1016/j.jhazmat.2023.132785. Epub 2023 Oct 14.
Studying microplastics and nanoplastics (MNP) in environmental matrices is extremely challenging, and recent developments in labelling techniques may hold much promise to further our knowledge in this field. Here, we reviewed MNP labelling techniques and applications to provide the first systematic and in-depth insight into MNP labelling. We classified all labelling techniques for MNP into four main types (fluorescent, metal, stable isotope and radioisotope) and discussed per type the synthesis methods, detection methods, influencing factors, and the current and future applications and challenges. Direct labelling of environmental MNP with fluorescent dyes and metals enables simple visualisation and selective detection of MNP to improve detection efficiency. However, it is still an open question how to avoid co-labelling of non-plastic (i.e. non-target, matrix) materials. Labelling of MNP that are intentionally added in the environment may allow semi-automatic detection of MNP particles with high accuracy and sensitivity during studies on e.g. transport and degradation. The detection limit of labelled MNP largely depends on particle size and the type of matrix. Fluorescent labelling allows efficient detection of microplastics, whereas metal labelling is preferred for nanoplastics research due to a potentially higher sensitivity. A major challenge for fluorescent and metal labelling is to develop techniques that do not alter the inherent MNP properties or only do so minimally, in particular the surface properties. Stable and radioactive isotope labelling (C and C, but also N, H) of the polymer itself allows to preserve inherent MNP properties, but have been largely ignored. Overall, labelling of MNP holds great promise for advancing our fundamental understanding of the behaviour of plastics, notably the smallest fractions, in the environment.
研究环境基质中的微塑料和纳米塑料（MNP）极具挑战性，而标记技术的最新进展有望在该领域增进我们的了解。在此，我们回顾了MNP标记技术及其应用，以便首次对MNP标记进行系统且深入的洞察。我们将所有MNP标记技术分为四种主要类型（荧光、金属、稳定同位素和放射性同位素），并针对每种类型讨论了合成方法、检测方法、影响因素以及当前和未来的应用与挑战。用荧光染料和金属对环境中的MNP进行直接标记，能够实现MNP的简单可视化和选择性检测，从而提高检测效率。然而，如何避免对非塑料（即非目标、基质）材料进行共标记仍是一个悬而未决的问题。对环境中故意添加的MNP进行标记，可能有助于在例如运输和降解研究期间以高精度和灵敏度半自动检测MNP颗粒。标记后的MNP的检测限很大程度上取决于颗粒大小和基质类型。荧光标记能够高效检测微塑料，而金属标记由于潜在的更高灵敏度，更适合用于纳米塑料研究。荧光和金属标记面临的一个主要挑战是开发不会改变或仅最小程度改变MNP固有特性，特别是表面特性的技术。聚合物本身的稳定和放射性同位素标记（碳-13和碳-14，还有氮-15、氢-3）能够保留MNP的固有特性，但在很大程度上被忽视了。总体而言，MNP标记对于推进我们对环境中塑料，尤其是最小颗粒部分行为的基本理解具有巨大潜力。
