Engineering a SERS Sensing Nanoplatform with Self-Sterilization for Undifferentiated and Rapid Detection of Bacteria

The development of a convenient, sensitive, rapid and self-sterilizing biosensor for microbial detection is important for the prevention and control of foodborne diseases. Herein, we designed a surface-enhanced Raman scattering (SERS) sensing nanoplatform based on a capture-enrichment-enhancement strategy to detect bacteria. The gold-Azo@silver-cetyltrimethylammonium bromide (Au-Azo@Ag-CTAB) SERS nanotags were obtained by optimizing the synthesis process conditions. The results showed that the modification of CTAB enabled the nanotags to bind to different bacteria electrostatically. This SERS sensing nanoplatform was demonstrated to be fast (15 min), accurate and sensitive (limit of detection (LOD): 300 and 400 CFU/mL for E. coli and S. aureus, respectively). Of note, the excellent endogenous antibacterial activity of CTAB allowed the complete inactivation of bacteria after the assay process, thus effectively avoiding secondary contamination.

Automated summary

The development of a convenient, sensitive, rapid, and self-sterilizing biosensor for microbial detection is of great importance for preventing and controlling foodborne diseases. In this study, a surface-enhanced Raman scattering (SERS) sensing nanoplatform was designed based on a capture-enrichment-enhancement strategy to detect bacteria. The SERS nanotags of gold-Azo@silver-cetyltrimethylammonium bromide (Au-Azo@Ag-CTAB) were obtained by optimizing the synthesis process conditions. The modified CTAB enabled the nanotags to electrostatically bind to different bacteria, allowing for fast (15 min), accurate, and sensitive detection (limit of detection: 300 and 400 CFU/mL for E. coli and S. aureus, respectively). Additionally, the endogenous antibacterial activity of CTAB ensured complete bacteria inactivation after the assay process, effectively avoiding secondary contamination.