MoS2 based digital response platform for aptamer based fluorescent detection of pathogens

The authors describe a method for detecting the pathogen S. typhimurium with a ‘yes-or-no’ kind of response. A fluorescein-tagged aptamer (Apt-FAM) probe was used for the specific recognition of pathogens, and molybdenum(IV) disulfide nanosheets (MoS 2 -Ns) were used as a primary binder of free (unbound) ssDNA that quenches its fluorescence. If, however, target pathogens are present, Apt-FAM probe binds to it and fluorescence is restored. The method displays a detection limit of 10 CFU·mL −1 , is selective over E. coli and P. vulgaris , and therefore represents a promising on-site screening tool for microbes. Graphical abstract Molybdenum disulfide nanosheets (MoS 2 -Ns) act as primary binder of free fluorophore labelled ssDNA aptamer and quenches its fluorescence. If target pathogens are present aptamer binds to it instead of MoS 2 -Ns and fluorescence is restored.