Biocompatible and biodegradable electrode platforms were developed using laser-scribed poly(lactic acid)/graphene oxide (PLA/GO) composites, prepared via an innovative waterborne dispersion method. Laser treatment enabled the formation of graphene/graphite-like structures. By varying the fluence of the laser used, it was possible to modulate the physico-chemical properties of the conductive traces obtained, finally leading to materials characterized by tunable sheet resistance, chemical structure, and morphology. Thanks to the low charge transfer resistance and the peculiar electrocatalytic and antifouling properties observed, the platforms were applied as electrochemical sensors for the detection of various biomarkers in biological fluids, namely ascorbic and uric acid, nicotinamide adenine dinucleotide (NADH) and catecholamine-based neurotransmitters, outperforming commercial carbon screen-printed electrodes. Contextually, laser-scribed electrodes were used to demonstrate the effectiveness of a novel approach for selectively stimulating Ca signaling in astrocytes. The results here reported open the possibility to apply laser-scribed PLA/GO as innovative eco-sustainable solutions for simultaneous treatment of pathological conditions and monitoring of the resulting neurotransmitter expression in in vitro and in vivo models.