blood, serum, urine). [1][2][3] Catecholamines, including DA, noradrenaline, levodopa, norepinephrine, serotonin are fundamental neurotransmitters governing neural communication, as well as vascular and hormone functions. [4,5] DA levels analysis in biological complex fluids, especially cerebrospinal fluid (CSF), is an intriguing challenge to perform an early diagnosis of several neural diseases and then therapeutic treatments. [6][7][8] Parkinson's, Huntington's, Alzheimer's diseases, Schizophrenia, epilepsy, and memory loss are some of the widespread neural sicknesses related to DA down-level in the CSF. [8][9][10] In healthy patients, DA CSF levels are reported to be in the 0.5× 10 −9 to 25 × 10 −9 m concentration range, [11] whilst, in Parkinson's disease affected people, DA CSF levels drop down to sub-nanomolar concentration (below 100 × 10 −12 m). [12,13] In the last years, in order to reply to the demand of ultrasensitive DA detection in biological fluids, as CSF or sera, the researchers' interest in innovative optical and spectroscopic sensing systems, especially based on surface enhanced Raman scattering (SERS) and surface plasmon resonance (SPR) methods, has been constantly rising. [14][15][16][17] In fact,