Bacteria imprinted electrochemical sensor based on bimetallic silver-gold sea urchin-like hollow nanoparticles for ultrasensitive detection of Listeria monocytogenes

Food safety problems caused by foodborne pathogens pose a serious threat to human health and its sensitive detection is an urgent issue. Herein, a polydopamine film-based electrochemical biosensor was constructed for ultrasensitive detection of Listeria monocytogenes ( L. monocytogenes ). Bimetallic silver-gold sea urchin-like hollow nanoparticles (BUHNPs) were first synthesized and loaded on the surface of a glassy carbon electrode, and then aptamers (apt) were modified on the BUHNPs , followed by depositing of dopamine to form polydopamine of bacterial imprinted polymers (PDA BIPs) film, and finally three-dimensional molecularly imprinted films with cavities were achieved after template elution. The presence of L. monocytogenes resulted in a change in the current signal, indicating that the bacteria had entered the cavity. The biosensor was able to detect L.monocytogenes at 10 1 -10 6 CFU·mL −1 with a detection limit of 1.0 CFU·mL −1 . The sensor can achieve rapid detection within 7 min, and the synergistic effect of BIP and aptamer enhances the recognition of the target, showing a great potential for the detection of L. monocytogenes in real food samples.