A novel biosensor MDC@N-MMCNs to selective detection and elimination of foodborne bacterial pathogens

Infections caused by foodborne pathogens pose a major threat to human health. Traditional bacterial detection methods, such as plate culture and polymerase chain reaction, cannot meet the growing demand for fast and accurate detection. In contrast, colorimetric sensors have the characteristics of convenience, speed, and visualization, but their specific sensitivity is relatively poor. Therefore, it is necessary to develop a biosensor with selective identification of foodborne pathogens, high sensitivity, and early detection of foodborne pathogen contamination in food.

We have developed a broad-spectrum microbial detection biosensor platform MDC@N-MMCNs that combines antimicrobial peptides as identifying ingredients with mesoporous carbon with peroxidase-like activity to detect and eliminate foodborne pathogens rapidly. In this study, nitrogen-doped magnetic mesoporous carbon nanospheres (N-MMCNs) were prepared using ferric nitrate as the magnetic source. Musca domestica cecropin (MDC) has abundant recognition sites on the surface of bacteria, which helps to recognize and amplify the signal, and combines with N-MMCNs to form MDC@N-MMCNs. MDC@N-MMCNs have high stability, specificity, and sensitivity, with a visual detection limit as low as 10² CFU/mL. The MDC@N-MMCNs paper-based sensor enables selective and rapid detection of four foodborne pathogens via a smartphone application.

Based on these findings, we believe that MDC@N-MMCNs hold great potential for on-site bacterial infection diagnosis in resource-limited environments or point-of-care (POCT) settings, offering a simple, cost-effective solution for food safety and public health.