A novel approach to detect barium in gunshot residue using a handheld device: a forensic application
Abstract
The present manuscript describes an innovative handheld device for the rapid detection of barium (Ba2+) in Gunshot Residue (GSR) based on the use of gold nanomaterials capped with sodium malonate. The method depends on a shift in the Light Scattering Plasmon Resonance (LSPR) peak of malonate capped gold nanoparticles (AuNPs) from 526 nm to 610.5 nm, due to the carboxylate ion aggregation between the metal and the nanoparticles leading to a change in the color. Qualitative detection was realized by the change in the color, while for quantitative analysis a handheld device has been fabricated in-house. The results were then correlated with those of standard known methods such as UV-Vis Spectroscopy and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). The results showed better correlation between the fabricated device and standard methods with R2 = 0.98. It shows a linearity range from 0.01 mg mLâ1 to 5 mg mLâ1 with a Limit of Detection (LOD) of 0.2 mg mLâ1. Furthermore, GSR samples were collected from cloth piece set at different range of shooting (i.e. 1 ft to 16.40 ft) using different ammunition to detect the presence of Ba2+ with the help of the developed device and results were found similar to those of the known methods. The hand-held device was found to be unaffected by other interfering agents (i.e. Pb2+, Sb3+, Ca2+, Cu2+, Hg2+, Mg2+, As3+, Cr3+, etc.). The results demonstrated here shows high selectivity, sensitivity and rapid method for Ba2+ detection in GSR, showing its greater potentiality in future.
- This article is part of the themed collection: Analytical Methods HOT Articles 2021