A ruthenium(IV) disulfide based non-enzymatic sensor for selective and sensitive amperometric determination of dopamine.

An electrochemical dopamine (DA) sensor has been fabricated by modifying a glassy carbon electrode (GCE) with ruthenium disulfide (RuS2) nanoparticles (NPs). FESEM and TEM micrographs show the NPs to have an average size of ~45 nm. XRD, Raman and EDS, in turn, confirm the successful formation of cubic phased RuS2 NPs. The modified GCE displays has attractive features of merit that include (a) an ultra-low detection limit (73.8 nM), (b) fast response time (< 4 s), (c) a low oxidation potential (0.25 V vs. Ag|AgCl), (d) excellent reproducibility and stability, (e) an electrochemical sensitivity of 18.4 μA μM-1 cm-2 and 1.8 μA.μM-1.cm-2 in the linear ranges from 0.1-10 μM of DA (R2 = 0.97) and 10-80 μM of DA (R2 = 0.99), respectively. The sensor exhibits excellent specificity over potential interferents like ascorbic acid, glucose and uric acid. The superior performance of the sensor is attributed to its high electrical conductivity, large electro-active surface, and large numbers of exposed catalytically active sites resulting from the presence of unreacted sulfur atoms. Graphical abstract A ruthenium disulfide modified electrochemical sensor material was obtained by single-step hydrothermal synthesis. Sensitive and highly selective detection of dopamine is demonstrated.