Dual-functional carboxymethyl chitosan-coated silver nanoparticles for bacterial detection integrated with spectral...

Area of Science:

• Nanomaterials Science
• Food Safety
• Microbiology

Background:

• Advancing food safety requires effective microbial detection and sterilization methods.
• Current methods may lack sensitivity or dual functionality.
• Nanomaterials offer potential for integrated solutions.

Purpose of the Study:

• To develop a dual-functional nanomaterial for simultaneous microbial detection and sterilization.
• To synthesize and characterize carboxymethyl chitosan coated with spherical silver nanoparticles (CMCS@Ag NPs).
• To evaluate the performance of CMCS@Ag NPs in detecting and inhibiting common foodborne pathogens.

Main Methods:

• Synthesis of CMCS@Ag NPs.
• Surface-enhanced Raman spectroscopy (SERS) with deuterium isotope labeling for bacterial detection.
• Algorithm-based spectral preprocessing (air-PLS + MAS) and Principal Component Analysis (PCA) for microbial discrimination.
• Antibacterial assays to assess sterilization efficacy.

Main Results:

• CMCS@Ag NPs demonstrated enhanced SERS signal stability for detecting E. coli, S. aureus, and S. putrefaciens.
• Achieved a detection sensitivity of 0.64 CFU/mL for E. coli.
• Optimized spectral preprocessing (air-PLS + MAS) and PCA enabled successful discrimination of the three bacterial strains.
• CMCS@Ag NPs exhibited potent antibacterial activity, reducing bacterial viability by 99% within 45 minutes.

Conclusions:

• CMCS@Ag NPs represent a versatile nanomaterial for simultaneous pathogen detection and inhibition.
• This strategy significantly advances food safety applications.
• The developed nanomaterial shows promise for real-time monitoring and control of microbial contamination.