Enzyme-accelerated catalytic DNA circuits enable rapid and one-pot detection of bacterial pathogens

Catalytic DNA circuits, serving as signal amplification strategies, can enable simple and accurate detection of pathogenic bacteria in complex matrices but suffer from low reaction rates and depths. Herein, we design an enzyme-accelerated catalytic hairpin assembly (EACHA) in which duplex DNA products are converted into hairpin reactants to continue participating in the next circuit reaction with the assistance of RNase H. Profiting from the high recyclability of the reactants, EACHA exhibits an approximately 37.6-fold enhancement in the rate constant and a two-order-of-magnitude improvement in sensitivity compared to conventional catalytic hairpin assembly (CHA). By integrating an allosteric probe with EACHA, a one-pot method is developed for rapid and direct detection of S. enterica Enteritidis (S. Enteritidis). This method is capable of detecting 15 CFU mL