This work focuses on the synthesis and the comprehensive characterization of polydianiline (PDANI) polymer, obtained via oxidative polymerization of dianiline, a low-toxicity and more environmentally friendly starting monomer for polyaniline (PANI) formation. Despite the structural similarity to PANI, PDANI remains underexplored, especially regarding the effect of different synthesis conditions. Here, we investigate how chloride, sulfate, and camphor sulfonate dopants, combined with green solvents such as water and DMSO, modulate the final properties of PDANI in the emeraldine salt configuration. The produced materials were extensively characterized using a multi-technique approach. FTIR, Raman, EPR, and UV-Vis spectroscopies provided insights into chemical structure, molecular order, and polaron population. Electrical conductivity was disclosed via current-voltage (I-V) measurements, while cyclic voltammetry (CV) and coulovoltammetry (QV) were employed to evaluate redox activity and charge reversibility. The resulting PDANI displays structural and functional features comparable to those of PANI synthesized under similar conditions. Notably, the nature of the dopant and acidic medium was found to crucially govern the oxidation level, molecular organization, and electrochemical performance, boosting PDANI as a tunable and sustainable alternative for applications ranging from electronics to energy storage.

Carbon is a versatile electrode material that is used in applications ranging from electrical energy storage and electrosynthesis to CO ₂ conversion, H ₂ production, and biosensing. The development of pyrolytic carbon electrodes derived from lithographically patterned photoresist structures has expanded the possibilities for creating diverse 2D and 3D electrode designs. In this paper, we present disc-shaped SU-8-derived pyrolytic carbon scaffold electrodes with an open hexagonal honeycomb lattice. The scaffolds were fabricated, using embedded 3D printing within a shear-thinning support bath composed of fused silica nanoparticles (7% w/v) in mineral oil. The rheological properties of the support bath were optimized to enable the printing of low-viscosity materials like SU-8, which would otherwise lack structural integrity in standard extrusion-based 3D printing. The SU-8 scaffolds were then pyrolyzed and characterized using SEM, Raman spectroscopy, Energy Dispersive X-ray, X-ray Photoelectron Spectrometry, and Transmission Electron Microscopy, which revealed graphene-like ‘microflowers’ on its surface. Electrochemical analysis demonstrated excellent electrochemical properties. The functionality of the scaffold electrodes was validated by differentiation of human neural stem cells into dopaminergic neurons on the scaffold surface, followed by real-time detection of dopamine exocytosis upon cell depolarization. Supplementary information for this article is available on-line.