Ratiometric fluorescence and visual sensing of ATP based on gold nanocluster-encapsulated metal-organic framework with a smartphone

Adenosine triphosphate (ATP) plays an important role in various biological processes and the ATP level is closely associated with many diseases. Herein, we designed a novel dual-emissive fluorescence nanoplatform for ATP sensing based on red emissive europium metal-organic framework (Eu-MOF) and blue emissive gold nanoclusters (AuNCs). The presence of ATP causes the decomposition of Eu-MOF owing to strong affinity of Eu³⁺ with ATP. As a result, the red emission of Eu-MOF decreases while the blue emission of AuNCs remains unchanged. The distinct red/blue emission intensity change enables the establishment of a ratiometric fluorescent and visual sensor of ATP. Moreover, a fluorescent paper-based sensor was fabricated with the ratiometric ATP probes, which enabled easy-to-use and visual detection of ATP in serum samples with a smartphone.