Labeling Microplastics with Fluorescent Dyes for Detection, Recovery, and Degradation Experiments
Staining microplastics (MPs) for fluorescence detection has been widely applied in MP analyses. However, there is a lack of standardized staining procedures and conditions, with different researchers using different dye concentrations, solvents, incubation times, and staining temperatures. Moreover,...
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| Format: | Article |
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MDPI AG
2022-11-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/27/21/7415 |
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| author | Zhiqiang Gao Kendall Wontor James V. Cizdziel |
| author_facet | Zhiqiang Gao Kendall Wontor James V. Cizdziel |
| author_sort | Zhiqiang Gao |
| collection | DOAJ |
| description | Staining microplastics (MPs) for fluorescence detection has been widely applied in MP analyses. However, there is a lack of standardized staining procedures and conditions, with different researchers using different dye concentrations, solvents, incubation times, and staining temperatures. Moreover, with the limited types and morphologies of commercially available MPs, a simple and optimized approach to making fluorescent MPs is needed. In this study, 4 different textile dyes, along with Nile red dye for comparison, are used to stain 17 different polymers under various conditions to optimize the staining procedure. The MPs included both virgin and naturally weathered polymers with different sizes and shapes (e.g., fragments, fibers, foams, pellets, beads). We show that the strongest fluorescence intensity occurred with aqueous staining at 70 °C for 3 h with a dye concentration of 5 mg/mL, 55 mg/mL, and 2 µg/mL for iDye dyes, Rit dyes, and Nile red, respectively. Red fluorescent signals are stronger and thus preferred over green ones. The staining procedure did not significantly alter the surface, mass, and chemical characteristics of the particles, based on FTIR and stereomicroscopy. Stained MPs were spiked into freshwater, saltwater, a sediment slurry, and wastewater-activated sludge; even after several days, the recovered particles are still strongly fluoresced. The approach described herein for producing customized fluorescent MPs and quantifying MPs in laboratory-controlled experiments is both straightforward and simple. |
| first_indexed | 2024-03-09T18:48:01Z |
| format | Article |
| id | doaj.art-78b3cff5ac5e4c66a7a7b731bd782a0a |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-09T18:48:01Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-78b3cff5ac5e4c66a7a7b731bd782a0a2023-11-24T06:03:49ZengMDPI AGMolecules1420-30492022-11-012721741510.3390/molecules27217415Labeling Microplastics with Fluorescent Dyes for Detection, Recovery, and Degradation ExperimentsZhiqiang Gao0Kendall Wontor1James V. Cizdziel2Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677, USADepartment of Chemistry and Biochemistry, University of Mississippi, University, MS 38677, USADepartment of Chemistry and Biochemistry, University of Mississippi, University, MS 38677, USAStaining microplastics (MPs) for fluorescence detection has been widely applied in MP analyses. However, there is a lack of standardized staining procedures and conditions, with different researchers using different dye concentrations, solvents, incubation times, and staining temperatures. Moreover, with the limited types and morphologies of commercially available MPs, a simple and optimized approach to making fluorescent MPs is needed. In this study, 4 different textile dyes, along with Nile red dye for comparison, are used to stain 17 different polymers under various conditions to optimize the staining procedure. The MPs included both virgin and naturally weathered polymers with different sizes and shapes (e.g., fragments, fibers, foams, pellets, beads). We show that the strongest fluorescence intensity occurred with aqueous staining at 70 °C for 3 h with a dye concentration of 5 mg/mL, 55 mg/mL, and 2 µg/mL for iDye dyes, Rit dyes, and Nile red, respectively. Red fluorescent signals are stronger and thus preferred over green ones. The staining procedure did not significantly alter the surface, mass, and chemical characteristics of the particles, based on FTIR and stereomicroscopy. Stained MPs were spiked into freshwater, saltwater, a sediment slurry, and wastewater-activated sludge; even after several days, the recovered particles are still strongly fluoresced. The approach described herein for producing customized fluorescent MPs and quantifying MPs in laboratory-controlled experiments is both straightforward and simple.https://www.mdpi.com/1420-3049/27/21/7415microplasticsfluorescencetextile dyesNile redhydrophobicity |
| spellingShingle | Zhiqiang Gao Kendall Wontor James V. Cizdziel Labeling Microplastics with Fluorescent Dyes for Detection, Recovery, and Degradation Experiments Molecules microplastics fluorescence textile dyes Nile red hydrophobicity |
| title | Labeling Microplastics with Fluorescent Dyes for Detection, Recovery, and Degradation Experiments |
| title_full | Labeling Microplastics with Fluorescent Dyes for Detection, Recovery, and Degradation Experiments |
| title_fullStr | Labeling Microplastics with Fluorescent Dyes for Detection, Recovery, and Degradation Experiments |
| title_full_unstemmed | Labeling Microplastics with Fluorescent Dyes for Detection, Recovery, and Degradation Experiments |
| title_short | Labeling Microplastics with Fluorescent Dyes for Detection, Recovery, and Degradation Experiments |
| title_sort | labeling microplastics with fluorescent dyes for detection recovery and degradation experiments |
| topic | microplastics fluorescence textile dyes Nile red hydrophobicity |
| url | https://www.mdpi.com/1420-3049/27/21/7415 |
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