Swipe and Scan: Integration of sampling and analysis of gunshot metal residues at screen-printed electrodes

摘要

Increasing security needs require field-deployable, on-the-spot detection tools for the rapid and reliable identification of gunshot residue (GSR), and thus the collection of GSR samples is a crucial step in forensic analysis. In this work we demonstrate a novel protocol integrating GSR sampling and electroanalysis using microfabricated carbon sensor-strips. The new integrated sampling/detection methodology relies on abrasive stripping voltammetry (AbrSV) involving an initial mechanical transfer of trace amounts of surface-confined GSR from the hand of a suspect directly onto the electrode contingent of the sensor strip, which is immediately ready for electrochemical analysis. The integrated sampling/detection method holds much promise as a portable, rapid and inexpensive system to promptly identify a subject who has discharged a firearm in various forensic scenarios.