Gold nanostructures electrodeposited on graphene oxide-modified indium tin oxide glass as a surface-enhanced Raman scattering-active substrate for ultrasensitive detection of dopamine neurotransmitter

Dopamine (DA) is a neurotransmitter closely relate to the dysfunction and the deficiency of the dopaminergic system. Surface-enhanced Raman scattering (SERS) is a promising analytical tool that can identify the DA levels in biological fluid containing various components. In this study, we fabricated a SERS-active substrate by electrodepositing Au nanoparticles (NPs) on the indium tin oxide (ITO) glass modified with graphene oxide. The morphology of the Au NPs was optimized by adjusting the concentration of the Au precursor and electrodeposition parameters (such as cycle numbers, two-step potentials, and depositing times). The optimized substrate could detect dopamine in standard DA down to similar to 10(-10)M and successfully determine the plasma DA (10(-8)-10(-9) M) in human blood samples. (C) 2018 The Japan Society of Applied Physics