Tin disulfide nanorod-graphene-ß-cyclodextrin nanocomposites for sensing dopamine in rat brains and human blood serum.

ABSTRACT

In the present work describes a facile synthesis of tin disulfide (SnS2) nanorods decorated graphene-ß-cyclodextrin (SnS2/GR-ß-CD) nanocomposite for robust and novel dopamine (DA) electrochemical biosensor applications. The DA biosensor was fabricated using the glassy carbon electrode (GCE) modified with SnS2/GR-ß-CD nanocomposite. The sonochemical and hydrothermal methods have been used for the synthesis of SnS2/GR-ß-CD. Different physicochemical methods were used to confirm the formation of the GR-ß-CD, SnS2, and SnS2/GR-ß-CD nanocomposite. The cyclicvoltammetric cathodic current response of DA was 5 folds higher than those observed at bare, ß-CD, SnS2-ß-CD, and GR-ß-CD modified GCEs. Under optimised conditions, the biosensor's DPV response current is linear to DA from the concentration of 0.01-150.76 µM. The detection limit of the biosensor was 4 nM. The SnS2/GR-ß-CD biosensor shows an excellent selectivity towards DA in the presence of common interfering species, including ascorbic acid and uric acid. Also, the as-prepared nanocomposite-modified electrode exhibited satisfactory long-term stability, sensitivity (2.49 µAµM-1 cm-2) along with reusability for detection of DA. The fabricated SnS2/GR-ß-CD biosensor was successfully used for the detection of DA in the rat brain and human blood serum samples.