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.