Evolution of novel rGO/ZrHCF composite and utility in electrocatalysis towards nanomolar detection of sodium nitrite and ferulic acid

Abstract

Novel composite of reduced graphene oxide/zirconium hexacyanoferrate (rGO/ZrHCF) was fabricated via electrochemical deposition and used as a sensor for detecting sodium nitrite and ferulic acid. The sensor was thoroughly characterized using scanning electron microscope, DRS-UV, attenuated total reflection IR spectroscopy as well as atomic force microscopy. The rGO/ZrHCF exhibited cube-like morphology of ZrHCF on multilayered rGO sheets. Electrochemical characterization was carried out using cyclic voltammetry and square wave voltammetry for the detection of ferulic acid and sodium nitrite. Ferulic acid and sodium nitrite are used as food additives and the overdose of either of them can result in various physiological ailments and necessitates their detection. The proposed sensor could detect both sodium nitrite and ferulic acid at nanomolar levels exhibiting linearity in the range of 1.14 to 13.77 nM and 3.23 to 41.98 nM, respectively. The corresponding limit of detection was 0.38 nM and 1.39 nM. The rGO/ZrHCF-modified electrode was checked for real sample analysis by carrying out determination of sodium nitrite and ferulic acid in water and milk samples and the recovery percentages were found to be in between 96.15 and 99.80. The sensor exhibited long-term stability and reproducibility.