Detection of Neurotransmitters by Three-Dimensional Laser-Scribed Graphene Grass Electrodes

Carbon nanomaterials possess superb properties and have contributed considerably to the advancement of integrated point-of-care (POC) chemical and biological sensing devices. Graphene has been widely researched as a signal transducing and sensing material. Here, a grass-like laser scribed graphene (LSG) was synthesized by direct laser induction on common polyimide plastics. The resulting LSG grass was employed as a disposable electrochemical sensor for the detection of three neurotransmitters, dopamine (DA), epinephrine (EP) and norepinephrine (NE), and in the presence of uric acid (UA) and ascorbic acid (AA) as potential interferants, using differential pulse voltammetry (DPV) and cyclic voltammetry (CV). The LSG grass sensor achieved a sensitivity of 0.243, 0.067 and 0.110 µA µM–1 for DA, EP and NE, respectively, while the limits of detection were 0.43, 1.1 and 1.3 µM, respectively. The selectivity of LSG grass was excellent for competing biomarkers with high structural similarity (EP versus NE, and EP ...