Practical SERS method for assessment of the washing durability of textiles containing silver nanoparticles

Authors: Nam, Sunghyun; ERNST, NICHOLAS - Tulane University; CHAVEZ, SONIA - University Of Connecticut; Hillyer, Matthew; Condon, Brian; GIBB, BRUCE - Tulane University; SUN, LUYI - University Of Connecticut; GUO, HULYUAN - University Of Massachusetts, Amherst; HE, LILI - University Of Massachusetts, Amherst

Submitted to: Analytical Methods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2020
Publication Date: 3/5/2020
Citation: Nam, S., Ernst, N., Chavez, S.E., Hillyer, M.B., Condon, B.D., Gibb, B.D., Sun, L., Guo, H., He, L. 2020. Practical SERS method for assessment of the washing durability of textiles containing silver nanoparticles. Analytical Methods. 12(9):1186-1196. https://doi.org/10.1039/C9AY02545F.
DOI: https://doi.org/10.1039/C9AY02545F

Interpretive Summary: We developed a simple yet effective SERS method to identify and quantify Ag NPs in washing solutions for the assessment of washing durability of textile products containing Ag NPs. The particle assembly formed by the “coffee ring” effect exhibited remarkable surface-enhancement ability in Raman signal of the indicator molecule of ferbam. The sensitivity and reproducibility of the resulting SERS response were greater than those from the complexation of ferbam with individual Ag NPs. This enhancement was attributed to the SERS active “hot spots” located in the junction between aggregated NPs on the coffee ring. The SERS intensities from the coffee rings formed by Ag NPs in DI water and detergent solution exhibited linear relationships with the concentration of Ag NPs. Using these calibration curves, the amounts of Ag NPs leached from Ag NP-treated cotton fabrics into washing solutions were quantified. The determined concentrations agreed with those determined by ICP-MS, supporting the practicality of the SERS method. As demonstrated in this study, surface-treated Ag NPs are easily detached from the textiles during washing. The proposed method is expected to allow fast and reliable assessment of the wash durability and facilitate the production of safe and leach-resistant Ag NP-functionalized textile products.

Technical Abstract: The popular use of silver nanoparticles (Ag NPs) in the production of commercial odor-control and antibacterial textile products has raised questions on their wash durability. The poor durability not only deteriorates product performance but also results in an unknown leaching of Ag NPs into sewer and water treatment systems. Therefore, it is necessary to have a facile and fast method to detect Ag NPs in washing solutions for the assessment of wash durability. In this study, we have developed a practical surface-enhanced Raman spectroscopy (SERS) method to measure the concentrations of Ag NPs in water and a detergent solution. To improve the sensitivity and reproducibility of SERS signals from the complexation of an indicator molecule (ferric dimethyl-dithiocarbamate, in this study) with NPs, the “coffee ring” effect was utilized. The SERS active “hot spots” in the aggregated NPs along the coffee ring effectively intensified the signature SERS response even with NPs of about 10 nm in diameter and a concentration as low as 0.01 mg/L. The linear relationships between SERS intensity and Ag NP concentration (R2 > 0.99) successfully quantified the amounts of Ag NPs released from Ag NP-treated cotton fabrics into washing solutions, which agreed with the results obtained by ICP-MS.