Electrochemical biosensor Bi2O3@Au@Apta based on Bi2O3 nanofibers for sensitive detection of ampicillin

The widespread use of antibiotics can lead to residues in the environment and food, which in turn affects health problems. The detection of antibiotic residues is urgent. In this work, an efficient and sensitive ampicillin (AMP) electrochemical ensemble sensor was prepared by electrostatic spinning synthesis of Bi2O3 nanomaterials combined with Au nanoparticles. Based on the detection results of differential pulse voltammetry (DPV), it was found that the peak current becomes smaller when the concentration of AMP is continuously increased, and shows a good linear relationship with the logarithm of AMP concentration. By optimizing the experimental conditions, the detection range of Bi2O3@Au@Apta sensor was from 1 nM to 10 mM with a detection limit of 0.88 nM, and the R2 was as high as 0.9914, with good selectivity, reproducibility and stability. When other interfering substances such as antibiotics and amino acids were added, AMP detection was almost unaffected and the sensor remained highly stable over 7 days. In addition, the Bi2O3@Au@Apta based electrochemical sensor can be used to determine AMP in real samples (tap water and milk).