Partial ligand-exchange synthesis of Pt/ZIF with superior oxidase-mimicking activity for dual-modal colorimetric/fluorescent detection of adenosine triphosphate in bacteria and pleural effusion.

Adenosine triphosphate (ATP), as the universal energy currency of life, plays central role in biological activities, and its quantitative detection is crucial for assessing biological activity and metabolic status. In fields such as environmental monitoring, food safety, and biomedicine, it is of great significance to sensitively detect ATP for identifying microbial contamination, evaluating cell viability, and even advancing early disease diagnosis. However, specific detection of ATP in real-world samples such as bacteria and body fluids remains challenging. Herein a platinum nanoparticle/ZIF-8 composite (Pt/ZIF) was successfully synthesized via a partial ligand exchange, which exhibits excellent oxidase-mimicking activity with catalytic efficiency (Vmax/Km =7.38 × 10-4 s-1) significantly surpassing many other nanozymes. Interestingly, ATP can competitively replace 2-methylimidazole in Pt/ZIF and induce Pt/ZIF framework to collapse, resulting in great decrease in enzyme activity. Leveraging the ATP-responsive properties of Pt/ZIF, a novel dual-modal colorimetric/fluorescent sensing platform was developed. The platform exhibited excellent analytical performance with detection ranges of 1-10 μM and 10-1000 μM (colorimetric mode), 0.001-1 μM and 1-1000 μM (fluorescent mode), and low detection limits of 98.21 nM and 0.64 nM, respectively. The as-developed sensor was applied to detect ATP in Escherichia coli cultures showing good correlation with bacterial growth stages as well as clinical pleural effusion samples revealing elevated ATP levels in cancer patients and inflammation patients versus controls satisfactorily. This work provides a powerful tool for the rapid detection of ATP in complex biological samples and demonstrates broad potential application potential.