Title: Titanium nano-columns on graphene monolayer or Cu electrode for electrochemical dopamine detection

Abstract

Titanium nano-columns/graphene monolayer-Cu electrode, was prepared using an advanced, glancing angle deposition by magnetron sputtering, physical vapor deposition (PVD) method and investigated for electrochemical dopamine detection. The nano-columns were grown, on a commercial single-layer graphene on copper foil substrate, almost vertical and at some points parallel to the atomic flux. The morphology and the surface were investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. The results shown that the average height of the nanocolumns is ~170 nm; while there are some spots on the electrode of inhomogeneous growth of nanocolumns. The electrochemical detection of dopamine with the as-prepared electrode was investigated using the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. According to the DPV results the low detection limit was 10 μΜ dopamine in neutral environment (PBS), at 36.6oC, while according to the calibration curve the current response-concentration presents an excellent linear relation (Figure 1 inset) and 200 μΑ/mM high sensitivity.