Forensic discrimination of authentic and counterfeit smartphones using ATR-FTIR spectroscopy combined with chemometric analysis.

[Display omitted] • Identification of counterfeit smartphones by conjoint ATR-FTIR and PLS-DA was proposed. • Infrared spectra from authentic and counterfeit smartphone glass screens are slightly different. • Chemometric analysis was useful to show latent information. • The multivariate model showed 100% accuracy for the discrimination of samples. • The proposed methodology is fast, cost-effective, easy, and non-destructive. Smartphone is a worldwide valuable and prevalent tool. The growing illegal fake device market is a harmful activity that needs to be fought. The lack of suitable identification methods for daily routine is one of the main obstacles in the fight against counterfeiters. In this study, the association between Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy and Partial Least Squares-Discriminant Analysis (PLS-DA) was for the first time applied to distinguish authentic and counterfeit smartphone glass screens. The sample set used to build models included the four leading brands in the Brazilian smartphone market. Principal components analysis (PCA) allowed reasonable discrimination between the two classes along the second principal component. On the other hand, the PLS-DA model showed perfect classification rates, since the sensitivity, specificity, and accuracy were equal to 100% for the validation set. Therefore, the combination of ATR-FTIR spectroscopy and PLS-DA provided a simple, low-cost, nondestructive, direct, fast, and environmentally friendly way to detect counterfeit smartphone screens in a forensic context. [ABSTRACT FROM AUTHOR]