In this work, a complete study is carried out for the optimised, direct and catalyst-free growth of vertically-stacked graphene-based structures targeting at improved performance drug monitoring. The nanostructures, ultimately forming a honeycomb network on the substrate, are fabricated by the implementation and comparison of seven combinations of growth conditions on both Si and SiO2 substrates. Pivotal features characterising the nanostructures i.e. layer thickness, sheet resistance, surface morphology and sensing performance are considered for verifying the quality and properties of the resulted graphene-based electrodes. The graphene-based sensing platform demonstrating optimum structural and electrochemical performance is finally implemented for drug screening showing high efficiency for the detection of a chemotherapeutic compound at low concentrations.