Lanthanum‐Based Perovskite Oxides and Graphitic Carbon Nitride Composite Nanostructures for Electrochemical Ascorbic Acid Detection

Accurate determination of ascorbic acid (AA, vitamin C), an essential, water‐soluble antioxidant widely found in foods and pharmaceutical products and playing a critical role in human health, is important for clinical diagnosis, pharmaceutical analysis, and food quality control. Therefore, developing electrochemical sensing platforms with high sensitivity, rapid response, low cost, and simple operating principles is essential for the precise and selective determination of AA. In this study, LaBO 3 /g‐C 3 N 4 (B = Mn, Fe, Co) nanocomposites were synthesized via a solution combustion route followed by ultrasonic coupling with graphitic carbon nitride (g‐C 3 N 4 ), and their electrochemical performance toward AA detection was systematically investigated. Comprehensive structural and physicochemical analyses confirmed the generation of highly crystalline perovskite oxides and their successful integration with g‐C 3 N 4 . LaCoO 3 /g‐C 3 N 4 (LCO/GCN) displayed superior optoelectronic and electrochemical properties, exhibiting the highest electrocatalytic activity toward AA oxidation with good selectivity, excellent reproducibility, operational cycling stability over 100 cycles, and successful applicability to real vitamin C samples analyses.