Preparation of CeO2QDs-g-C3N4/C composites and electrochemical determination of aflatoxin B1

The presence of Aflatoxin B1 (AFB1) in food represents a significant threat to human health, leading to the development of cancer. The key factor for effective trace detection technology lies in the utilization of sensor materials that exhibit excellent selectivity and high sensitivity properties. In this study, a successfully synthesis of g-C₃N₄/C with a high specific surface area uses melamine and houttuynia cordata stem as starting materials. A CeO₂QDs-g-C₃N₄/C composite was prepared by hydrothermally anchoring cerium oxide quantum dots (CeO₂QDs) onto the surface of g-C₃N₄/C, the high redox efficiency of CeO₂QDs and the small size limitation effect significantly improve the sensing performance. The composite was characterized by XRD, XPS, SEM, TEM, and N₂ adsorption-desorption. The results revealed that, the CeO₂QDs-g-C₃N₄/C composite sensor material exhibited significant advantages with a large specific surface area, a well-defined micropore structure, and abundant reactive sites. In addition, electrochemical activity tests are conducted using EIS, CV, and DPV for the purpose of electrochemical investigations. The CeO₂QDs-g-C₃N₄/C/GCE exhibits exceptional electrocatalytic activity against AFB1, with a wide linear response range of 100–1300 pg ml^-1, an impressively low detection limit (LOD) of 6.61 fg ml^-1 (S/N = 3), and a sensitivity of 0.985 pg μM ml^-1μA^-1. Furthermore, the stability, repeatability, and interference experimental response errors all remain below 5 %. It is also noteworthy that, the sensor material demonstrates excellent practicality in AFB1 assays conducted on real samples, which serves to illustrate its immense potential for applications in food safety evaluation.