Controlled electrochemical synthesis of new rare earth metal lutetium hexacyanoferrate on reduced graphene oxide and its application as a salicylic acid sensor

Abstract

The hexangular star building-like lutetium hexacyanoferrate (LuHCF) structure with an average size of ca. 8.0 ± 0.5 μm was synthesized using a simple, one-step electrochemical method, and it was highly dispersed on to a reduced graphene oxide (RGO) modified glassy carbon electrode (GCE) support for the first time. The size and shape of the as-synthesized LuHCF micro stars were controlled by the deposition time. The LuHCF/RGO samples were characterized by a variety of analytical and spectroscopy techniques, viz. scanning electron microscopy (SEM), infra-red spectroscopy (IR), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). In addition, LuHCF/RGO/GCE was adopted for the novel electrochemical detection of salicylic acid (SA) using cyclic voltammetry (CV) and amperometry methods. The charge transfer resistant value of LuHCF/RGO/GCE was smaller than LuHCF and bare GCE, which exhibit a remarkable electrocatalytic performance towards SA. Notably, the SA sensor was found to exhibit a lower detection limit and high sensitivity of ca. 0.49 μM and 77.2 μA mM⁻¹ cm⁻², respectively. The reported SA sensor possesses an excellent real time application with commercially purchased aspirin tablets and salic ointment (which contains salicylic acid). The excellent analytical parameters of the reported sensor, surpasses the previously reported modified electrodes, rendering practical industrial applications.