Role of Race/Ethnicity, Sex, and Age in Surface-Enhanced Raman Spectroscopy- and Infrared Spectroscopy-Based Analysis of Artificial Colorants on Hair

Abstract

Forensic microscopy has been used in forensic hair analysis to determine the racial origin of hair samples. However, this technique is subjective and often inconclusive. Although, to a large extent, this problem can be solved with the use of DNA analysis, which is capable of identifying the genetic code, biological sex, and racial origin from a strand of hair, this PCR-based analysis of hair is time-and labor-consuming. Infrared (IR) spectroscopy and surface-enhanced Raman spectroscopy (SERS) are emerging analytical techniques that can be used to advance forensic analysis of hair by enabling confirmatory identification of hair colorants.Having said that, it remains unclear whether the race/ethnicity, sex, and age of individuals should be considered upon IR spectroscopyand SERS-based analysis of hair. Our results showed that both techniques enabled robust and reliable analyses of hair of different races/ethnicities, sexes, and age groups colored using four different permanent and semipermanent colorants. We also found that SERS could be used to identify the race/ethnicity, sex, and age of the individuals via spectroscopic analysis of colored hair, whereas IR spectroscopy was capable of accurately revealing this important anthropological information only from uncolored hair. These results outlined some advantages and limitations of both vibrational techniques in the forensic examination of hair samples.

Trichoscopic findings in children and adults with alopecia areata: A comparative study

“…This specific finding provided a hopeful perspective for pediatric AA cases, contrasting with the absence of correlation between other dermoscopic features and clinical signs, challenging the universally diagnostic utility of trichoscopy in AA. 6,9,10 The study's findings on the occurrence of broken hairs and empty follicular openings in children, while statistically insignificant, aligned with observations from other research focusing on AA in darker skinned patients, indicating potential racial or skin type differences in AA presentation. 11 The observed higher prevalence of pigtail hairs in adults, despite not being statistically significant, reflected the nuanced variability of AA across different age groups.…”

“…Considering a comparison test for the ratio in two independent samples with a significance level of 0.05, 80% power, and a one-to-one ratio with an expected ratio of 0.4 in the first group and 0.65 in the second group, following a study, 6 the minimum required sample size was determined to be 124.…”

“…5 In particular, the use of advanced imaging modalities, such as Raman spectroscopy, has raised trichoscopy to a new level of diagnostic accuracy and added another tier of information on the pathogenesis of this disease. 6 However, the application of these advancements in the backdrop of the AA scenario, especially across different agewise sets of patients, still largely remains unexplored.…”

Using surface-enhanced Raman spectroscopy to probe artificial dye degradation on hair buried in multiple soils for up to eight weeks

“…Previously reported study by our group showed that SERS could be used to distinguish hair from different races/ethnicities, age groups, and sexes 15 . Therefore, the reported results should be valid only for young female individuals of Caucasian race.…”

Non-Destructive Identification of Dyes on Fabric Using Near-Infrared Raman Spectroscopy

“…RS has previously been used to identify urine, sweat, semen, blood, hair colorants, and gunshot residue [14][15][16][17][18][19]. It should be noted that RS is a non-destructive and non-invasive technique [20][21][22]. Therefore, it can be used to identify the origin of highly vulnerable historical fabrics that have dyes or pigments [9].…”