Helium-assisted, solvent-free electro-activation of 3D printed conductive carbon-polylactide electrodes by pulsed laser ablation

The fused deposition modeling is one of the most rapidly developing 3D printing techniques, with numerous applications, also in the field of applied electrochemistry. Here, utilization of conductive polylactic acid (C-PLA) for 3D printouts is the most promising, due to its biodegradability, commercial availability, and ease of processing. To use C-PLA as an electrode material, an activation process must be performed, removing the polymer matrix and uncovering the electroactive filler. The most popular chemical or electrochemical activation routes are done in solvents. In this manuscript, we present a novel, alternative approach towards C-PLA activation with Nd:YAG (lambda = 1064 nm) laser ablation. We present and discuss the activation efficiency based on various laser source operating conditions, and the gas matrix. The XPS, contact angle, and Raman analyses were performed for evaluation of the surface chemistry and to discuss the mechanism of the activation process. The ablation process carried out in the inert gas matrix (helium) delivers a highly electroactive C-PLA electrode surface, while the resultant charge transfer process is hindered when activated in the air. This is due to thermally induced oxide layers formation. The electroanalytical performance of laser-treated C-PLA in He atmosphere was confirmed through caffeine detection, offering detection limits of 0.49 and 0.40 microM (S/N = 3) based on CV and DPV studies, respectively.