A microfluidic chip enables fast analysis of water microplastics by optical spectroscopy

Abstract

Microplastics contaminating drinking water is a growing issue that has been the focus of a few recent studies, where a major bottleneck is the time-consuming analysis. In this work, a micro-optofluidic platform is proposed for fast quantification of microplastic particles, the identification of their chemical nature and size, especially in the 1–100 µm size range. Micro-reservoirs ahead of micro-filters are designed to accumulate all trapped solid particles in an ultra-compact area, which enables fast imaging and optical spectroscopy to determine the plastic nature and type. Furthermore, passive size sorting is implemented for splitting the particles according to their size range in different reservoirs. Besides, flow cytometry is used as a reference method for retrieving the size distribution of samples, where chemical nature information is lost. The proof of concept of the micro-optofluidic platform is validated using model samples where standard plastic particles of different size and chemical nature are mixed.

Advanced microplastic monitoring using Raman spectroscopy with a combination of nanostructure-based substrates

“…C-b A microscope picture of microfluidic chip reservoir containing a mixture of 20 µm PS particles and 6 µm PMMA particles, corresponding with Raman spectra. C-c A microscope picture of microfluidic chip reservoir containing 10 µm PMMA particles, corresponding with Raman spectroscopy of a single 10 µm PMMA particle [ 101 ]. Adapted with permission from Ref.…”

“…A reference method with flow cytometry was used to retrieve the distributed sizes of the MNP samples, but data on the chemical nature was therefore lost. To validate the potential application of this micro‑optofluidic platform, model samples containing standard MNP particles of different sizes and chemical natures were mixed and successfully checked [ 101 ].…”

“…Furthermore, due to their excellent enhancement of resonance Raman scattering spectroscopy, many researchers have been interested in developing the plasmonic nanomaterials-based SERS sensing method. In particular, also successfully developed for MNP detection are the plasmonic nanostructure-based SERS technique [ 88 – 91 ] with supporting silver nanoparticles (AgNPs) [ 92 ], gold nanoparticle (AuNP) substrates [ 93 ], gold nanostars [ 94 ], commercialized Klarite substrates [ 95 ], AuNP-decorated sponges [ 96 ], silver-coated gold nanostars [ 97 ], a single gold nanopore fabricated at the tip of a glass nanopipette [ 98 ], SiO 2 self-assembly sputtered with Ag films [ 99 ], Ag nanowire arrays on regenerated cellulose (RC) films [ 100 ], and microfluidic chips [ 101 ].…”

Microfluidic-based in vitro thrombosis model for studying microplastics toxicity

“…[16][17][18][19][20][21][22][23][24][25] However, there is still a gap in the study of the effects of MPs on the highly interacting vascular system. Optofluidic techniques 2,[26][27][28][29][30] enable precise optical manipulation of cells, particles [31][32][33][34][35][36][37][38][39] and reconfigurable tissue functionalization, [40][41][42][43] and so can be exploited to study the interaction of MPs with blood vessels.…”

Photonic Microfluidic Technologies for Phytoplankton Research

“…For this reason, they allow the precise control and manipulation of fluids, typically in a passive way. Microfluidic LOC technology represents a potential technical solution for environmental monitoring, for example, identification and classification of particles in water [ 16 , 17 ] like phytoplankton. Its main advantages are miniaturisation, portability, reduced reagent/sample consumption and automation and cost reduction.…”