Component identification for the SERS spectra of microplastics mixture with convolutional neural network

• Published in: The Science of the total environment 2023-10, Vol.895, p.165138-165138, Article 165138
• Main Authors: Luo, Yinlong, Su, Wei, Xu, Dewen, Wang, Zhenfeng, Wu, Hong, Chen, Bingyan, Wu, Jian
• Format: Article
• Language: English
• Subjects: Convolutional neural network; discriminant analysis; environment; Machine learning; microplastics; Microplastics identification; neural networks; principal component analysis; Raman spectroscopy; spectral analysis; Surface-enhanced Raman spectroscopy
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.165138

With the increasing interest in microplastics (MPs) pollutants, relevant detection technologies are also developing. In MPs analysis, vibrational spectroscopy represented by surface-enhanced Raman spectroscopy (SERS) is widely used because they can provide unique fingerprint characteristics of chemical components. However, it is still a challenge to separate various chemical components from the SERS spectra of MPs mixture. In this study, it is innovatively proposed to combine the convolutional neural networks (CNN) model to simultaneously identify and analyze each component in the SERS spectra of six common MPs mixture. Different from the traditional method, which requires a series of spectral preprocessing such as baseline correction, smoothing and filtering, the average identification accuracy of MP components is as high as 99.54 % after the unpreprocessed spectral data is trained by CNN, which is better than other classical algorithms such as support vector machine (SVM), principal component analysis linear discriminant analysis (PCA-LDA), partial least squares discriminant analysis (PLS-DA), Random Forest (RF), and K Near Neighbor (KNN), with or without spectral preprocessing. The high accuracy shows that CNN can be used to quickly identify MPs mixture with unpreprocessed SERS spectra data. [Display omitted] •Combine CNN and SERS technology to identify components of microplastics mixture.•Prove spectral preprocessing is unnecessary in the identification with CNN model.•SERS data acquisition process is significantly simplified to reduce processing time.•The average identification accuracy of MP components is as high as 99.54 %.