3D-printed electrochemical cells with laser engraving: developing portable electroanalytical devices for forensic applications

A new electrochemical device fabricated by the combination of 3D printing manufacturing and laser-generated graphene sensors is presented. Cell and electrodes were 3D printed by the fused deposition modeling (FDM) technique employing acrylonitrile butadiene styrene filament (insulating material that composes the cell) and conductive filament (lab-made filament based on graphite dispersed into polylactic acid matrix) to obtain reference and auxiliary electrodes. Infrared-laser engraved graphene, also reported as laser-induced graphene (LIG), was produced by laser conversion of a polyimide substrate, which was assembled in the 3D- printed electrochemical cell that enables the analysis of low volumes (50-2000 mu L). XPS analysis revealed the formation of nitrogen-doped graphene multilayers that resulted in excellent electrochemical sensing properties toward the detection of atropine (ATR), a substance that was found in beverages to facilitate sexual assault and other criminal acts. Linear range between 5 and 35 mu mol L-1, detection limit of 1 mu mol L-1, and adequate precision (RSD = 4.7%, n = 10) were achieved using differential-pulse voltammetry. The method was successfully applied to beverage samples with recovery values ranging from 80 to 105%. Interference studies in the presence of species commonly found in beverages confirmed satisfactory selectivity for ATR sensing. The devices proposed are useful portable analytical tools for on- site applications in the forensic scenario.

Automated summary

A new electrochemical device is developed by combining 3D printing and laser-generated graphene sensors. The device utilizes 3D-printed cells and electrodes, as well as laser-induced graphene, to achieve excellent electrochemical sensing properties for the detection of atropine in beverages. The method shows a linear range, low detection limit, and satisfactory precision, making it a useful portable analytical tool for on-site applications in the forensic scenario.