Determination of 2,4,6-trinitrotoluene using a 3D-printed flexible graphenepolylactic acid/poly caprolactone treated by blue-laser irradiation

In electroanalysis, the 3D-printed is employed in fabrication of electrodes, electrochemical cells and microfluidics systems [1]. 3D-printed electrodes typically require surface activation procedures, and the laser ablation method presents advantages, such as low cost, speed, and elimination of chemicals [2]. Therefore, this study aims the modification of graphene/polylactic acid/poly caprolactone electrode (GP/PLA/PCL) using blue-laser treatment for the improved detection of the explosive 2,4,6-trinitrotoluene (TNT). The GP/PLA/PCL electrodes were printed according to a previous work [3]. The blue-laser treatment was made using optimized conditions of laser power and speed of 280 mW and 30 mm s^-1, respectively. The GP/PLA/PCL electrodes were characterized by FT-IR spectroscopy, scanning electronic microscopy (SEM) and Raman spectroscopy. The initial studies show better analytical response for treated electrode with ΔEp = 128 mV compared to non-treated electrode (ΔEp = 437 mV) in 1.0 mmol L^-1 [Fe(CN)₆]^3-/4- in 0.1 mol L^-1 KCl solution. The analytical response for TNT also was compared between modified and non-modified electrodes, and the blue-laser treatment increase response for analyte. The TNT presents three reduction peaks at -0.31; -0.49 and -0.68 mV (vs. Ag|AgCl|KCl_(sat.)) using the modified electrode. The pH study indicates that the best conditions for TNT analysis in acidic medium. Therefore, 0.01 mol L^-1 HCl solution was used like electrolyte supporting for TNT determination.

Acknowledgments. CAPES, Fapemig, CNPq.

References.

[1] Veloso, W.B.; Ataide, V. N.; et. al., Microchimica Acta, 193, 63 (2023).

[2] Dettlaff, A.; Rycewicz, M.; et al., Microchimica Acta, 189, 270 (2022).

[3] Grazioli, C.; Svigelj, R.; et al. Electroanalysis, 35, 9 (2023).