A zeolitic imidazolate framework-90 enhanced ultrasensitive ATP sensing platform with HCR and CRISPR-Cas12a dual signal amplification for live bacteria detection

Bacteria are prevalent environmental pollutants. Live bacteria can proliferate and spread under appropriate conditions, presenting higher risks compared to non-viable counterparts. However, detecting live bacteria remains a challenge. Adenosine triphosphate (ATP), an energy currency in organisms, offers a reliable biomarker for the live bacteria sensing. Herein, we developed a zeolitic imidazolate framework-90 (ZIF-90) enhanced ATP sensing platform to detect live bacteria. The nanosystem which based on ZIF-90, encapsulating the DNA decorated magnetic beads (MB@S1) through self-assembly. When the S. aureus aptamers on ZIF-90 bonded to bacteria, the skeleton structure of ZIF-90 was disrupted by ATP leakage from live bacteria, leading to the release of MB@S1. Then, the MB@S1 initiated the hybridization chain reaction (HCR) and they were transduced by CRISPR-Cas12a to amplify the signal twice. The proposed ZIF-90 blocking sensing strategy (ZIF-90 strategy) exhibited remarkable sensitivity with the limit of detection (LOD) down to 0.223 pM for ATP detection, about 500 folds lower than the traditional ATP aptamer blocking sensing strategy (aptamer strategy). Furthermore, we used a smartphone for on-site analysis, realizing the quantification of live S. aureus with the LOD of 2.0 CFU/mL. Therefore, the approach possessed great application potential for public health, environment monitoring, bioanalysis and food safety.