Layer-by-Layer Self-Assembled Multilayer Films of Single-Walled Carbon Nanotubes and Tin Disulfide Nanoparticles with Chitosan for the Fabrication of Biosensors

In this study, multilayer films containing chitosan, tin disulfide (SnS2) nanoparticles, and single-walled carbon nanotubes were prepared on glassy carbon electrodes with the use of a layer-by-layer assembly technique. The resulting films were characterized with cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy, and ultraviolet-visible absorption spectroscopy. The results of CV and EIS indicates that the peak currents and charge-transfer resistance all had linear responses to the number of assembled layers. The multilayer-film-modified electrode showed excellent electrocatalytic properties for some species, such as dopamine hydrochloride (DA), ascorbic acid (AA), and uric acid (UA). The well-separated voltammetric signals of DA, UA, and AA could be obtained on the assembled multilayer-film-modified electrode, and the peak-to-peak potential separations were 171, 136, and 307 mV for DA-UA, DA-AA, and UA-AA on CV, respectively. These facts showed that the multilayer-film-modified electrode could be used as a new sensor for the simultaneous detection of DA and UA in the presence of AA in a real sample. In addition, the multilayer films were stable, selective, and reproducible. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 128: 647-652, 2013