Ultrafast and selective detection of dopamine by DC sputtered highly oriented CuO thin films: Effect of electroactive interfering agents and temperature

In this work, it has been aimed to synthesize a chip-based sensing platform that can detect dopamine precisely in a non-enzymatic way in presence of a series of electroactive interfering agents. Copper oxide (CuO), a p-type material with good surface attributes has been chosen to fabricate the sensing platform through DC sputtering technique on ITO (indium doped tin oxide) coated glass substrates. Detailed electrochemical investigations have been carried out through cyclic voltammetry and chronoamperometry. Excellent sensitivity (5.41 µAµM-1cm−2) and low limit of detection (LoD) of 0.46 µM have been revealed for the fabricated electrode towards dopamine, in comparison to serotonin and other interfering agents. This refers to good selectivity of the electrode towards dopamine. [Display omitted] •Selective and ultrafast detection of the neurotransmitter dopamine.•Highly oriented nanostructured copper oxide.•Novel platform for dopamine sensing through hole mediation.•Effect of temperature and a series of electroactive interfering agents.•Nonenzymatic/electrochemical process. Dopamine and serotonin are two neurotransmitters that play critical role in human physiology. In this work, it has been aimed to synthesize a chip-based sensing platform that can detect dopamine precisely in a non-enzymatic way in presence of a series of electroactive interfering agents. Copper oxide (CuO), a p-type material with excellent surface and electrochemical properties, has been deposited through direct current (DC) sputtering technique on indium doped tin oxide (ITO) coated glass substrates as the sensing platform. The structure, phase purity and other essential properties of the modified electrode were established through x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and ultraviolet – visible (UV–Vis) spectroscopy. Detailed electrochemical investigations with the modified electrode have also been carried out using cyclic voltammetry (CV), chronoamperometry (i – t) and electrochemical impedance spectroscopy (EIS) that revealed ultrafast response (10 ms), excellent sensitivity (5.41 µAµM-1cm−2) and low limit of detection (LoD) of 0.46 µM for the electrode towards dopamine. The electrode exhibited sensitivity of 0.37 µAµM-1cm−2 with average LoD of 19.2 µM towards serotonin, which is inferior to dopamine. The threshold response potential was also quite different for dopamin