Colloidal synthesis of perovskite-type lanthanum aluminate incorporated graphene oxide composites: Electrochemical detection of nitrite in meat extract and drinking water

A novel electrochemical method has been developed for determination of nitrite using La-based perovskite-type lanthanum aluminate nanorod-incorporated graphene oxide nanosheets (LaAlO₃@GO). Morphological and structural analyses of the prepared perovskite-type electrocatalyst, with and without a glassy carbon electrode (GCE) surface, were performed using various techniques, including transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry, Raman spectroscopy, and electrochemical impedance spectroscopy. Under optimal conditions, the LaAlO₃@GO composite-modified GCE (LaAlO₃@GO/GCE) exhibited excellent electrocatalytic performance toward the electrooxidation of nitrite (pH = 7.0), with a significant increase in anodic peak currents compared with the bare GCE. Using amperometry, the fabricated sensor exhibited a wide nitrite determination range from 0.01 to 1540.5 µM, with a detection limit of 0.0041 µM. Notably, the proposed LaAlO₃@GO/GCE electrode demonstrated a good nitrite detection performance in different meat and water samples. In addition, the LaAlO₃@GO/GCE electrode displayed excellent selectivity, repeatability, reproducibility, storage, and operational stability toward nitrite detection.