SERS driven cross-platform based multiplex pathogen detection

We demonstrate a cross-platform approach to simultaneously detect three different pathogens using Raman and UV–vis absorption spectroscopy. Gold (Au), silver (Ag), and Ag–Au core–shell nanoparticles were functionalized with anti-Salmonella typhimurium aptamers, anti-Staphylococcus aureus and anti-Escherichia coli O157:H7 antibodies respectively and labeled with unique Raman reporter molecules. A microfiltration step was used to consolidate a highly selective and specific detection platform, with total detection time under 45 min for both species (E. coli O157:H7 vs. S. typhimurium) and strain (E. coli O157:H7 vs. E. coli K12) level sensing at a limit of a detection ranging between 102 and 103 CFU/ml. This simple yet robust multiplex detection platform has the potential to be developed into a rapid and portable pathogen sensor for ultrasensitive detection in liquid samples.