Facile preparation of multilayer ultrathin films based on eriochrome black T/NiAl-layered double hydroxide nanosheet, characterization and application in amperometric detection of salicylic acid

- A new multilayer ultrathin film (UTF) containing EBT anions and exfoliated nanosheets of Ni-Al LDH was synthesized.
- The UTF was synthesized by LBL self-assembly technique and its properties were studied by electrochemical method.
- The UTF modified electrode presented a significant electrocatalytic performance towards the oxidation of salicylic acid.

A highly sensitive electrochemical sensor, EBT/LDH ultrathin film, for salicylic acid (SA) was fabricated in a facile way based on multilayer ultrathin films (UTFs) containing Eriochrome black T anions (EBT) and exfoliated Ni-Al layered double hydroxide (LDH) nanosheets via layer-by-layer self-assembly technique. The XRD pattern confirms that the products are nickel aluminum hydrotalcites, and SEM images shows continuous and uniform film surface. Electrochemical impedance spectroscopy (EIS), Current - time (i-T) and cyclic voltammetry (CV) methods were used to characterize the electrochemical behavior of the ultrathin film. The electrode modified with ultrathin film displays significantly high electrocatalytic performance for SA with sensitivity of 860 μAmM− 1 cm− 2, large concentrations ranging from 0.01 to 100 μM and with low detection limit 0.003 μM (S/N = 3). The EBT/LDH ultrathin film is shown to be a feasible electrochemical sensor for detection of SA.