Infrared spectroscopy and forensic entomology: Can this union work? A literature review

Abstract

For more than two decades, infrared spectroscopy techniques combined with multivariate analysis have been efficiently applied in several entomological fields, such as Taxonomy and Toxicology. However, little is known about its use and applicability in Forensic entomology (FE) field, with vibrational techniques such as Near-infrared spectroscopy (NIRS) and Medium-infrared spectroscopy (MIRS) underutilized in forensic sciences. Thus, this work describes the potential of NIRS, MIRS, and other spectroscopic methodologies, for entomological analysis in FE, as well as discusses its future uses for criminal or civil investigations. After a thorough research on scientific journals database, a total of 33 publications were found in scientific journals, with direct or indirect application to FE, including experimental applications of NIRS and MIRS in taxonomic discrimination of species, larval age prediction, detection of toxic substances in insects from environments or crime scenes, and detection of internal or external infestations by live or dead insects in stored products. Besides, NIRS and MIRS combined with multivariate analysis were efficient, inexpensive, fast, and nondestructive analytical tools. However, more than 51% of the spectroscopic publications are concentrated in the stored products field, and so we discuss the need for expansion and more direct application in other FE areas. We hope the number of articles continues to increase, and as NIRS and MIRS technology progress, they advance in forensic research and routine use.

Pupal Age Estimation of Sarcophaga peregrina (Diptera: Sarcophagidae) at Different Constant Temperatures Utilizing ATR-FTIR Spectroscopy and Cuticular Hydrocarbons

“…Insect metamorphosis is a complex process that includes a series of specific developmental events and programmed cell death to remodel the insect architecture through cell proliferation and differentiation, and many biochemical composition changes occur during this process [ 39 ]. ATR-FTIR may be used to evaluate the variations in biochemical composition in insect metamorphosis development based on the absorbance properties of spectroscopy since many functional groups within the biochemical composition have corresponding absorption peaks in the FTIR spectrum [ 40 ]. FTIR spectroscopy techniques have been used in some entomological fields, such as the taxonomic discrimination of species [ 41 ], larval age prediction [ 42 ], toxic substances identification and discrimination in necrophagous flies in entomotoxicology [ 43 ], and the detection of the infestations of insects in stored products.…”

Innovative Vibrational Spectroscopy Research for Forensic Application

“…However, there has been research into the collaboration of forensic entomology with vibrational spectroscopy. 278 This review article has discussed the application of NIR and MIR spectroscopies for species discrimination and larval age prediction, which are used for PMI calculations. In the same vein, to identify and estimate the taxonomic relationship between flies and their forensic potential, original research by de Andrade Silva et al used NIR spectroscopy paired with PCA and HCA.…”

“…Entomology is commonly used to determine the PMI for the initial stages of decomposition. However, there has been research into the collaboration of forensic entomology with vibrational spectroscopy . This review article has discussed the application of NIR and MIR spectroscopies for species discrimination and larval age prediction, which are used for PMI calculations.…”

Non-resonant MOEMS mirror for laser cavity-length tuning

“…It is a widely used method, 1 e.g., in health care and bioscience, 2-4 pharmaceutical industry, 5 food analysis, 6,7 environmental monitoring 8 or forensic entomology. 9 Among other efforts, intensive research is being conducted to develop broadband light sources with high spectral power density and resolution in order to further improve the sensitivity and signal quality of spectroscopy systems. Tunable MIR quantum cascade lasers (QCLs) are the first choice to meet these requirements.…”