DNA-templated fluorescent silver nanoclusters for sensitive detection of pathogenic bacteria based on MNP-DNAzyme-AChE complex

The rapid and sensitive detection of bacteria is of great importance for the field of food safety, water quality and clinical diagnosis. Herein, we present a novel DNA-templated fluorescent silver nanoclusters (DNA-AgNCs) based sensing system integrated with magnetic nanoparticles (MNP)-DNAzyme-AChE complex for detection of pathogenic bacterial using Escherichia coli (E. coli) as a target bacteria. The platform takes advantage of a DNA-AgNCs based enzyme-responsive fluorescent signal element and a DNAzyme recognition element, providing an ultrasensitive detection limit of 60 cfu mL−1, and good specificity to the target bacteria. Moreover, the platform could be developed into a potentially versatile system by simply altering corresponding DNAzyme as the objects recognition probes.