Tetraphenylethylene fluorophore based AIE-fluorescent probe for detection of ATP in mitochondria

A tetraphenylethylene fluorophore based on D-π-A structure was employed to design and synthesize the TPE-Py-FP probe for selective detection of ATP. TPE-Py-FP had the advantages of large Stokes shift, great hydrophilicity and good selectivity. Especially, the pyridine portion and quaternary ammonium structure of TPE-Py-FP had positively charged sites, which could be used as recognition groups to interact with the negatively charged triphosphate structure of ATP. Then the fluorescence emission of TPE-Py-FP at 580 nm showed a “turn-on” response after adding ATP. Moreover, this probe could rapidly respond to ATP over a wide linear range of 10–120 μM and the limit of detection (LOD) was 2.76 μM. The zeta potential and dynamic light scattering experiments revealed that the detection mechanism was mainly the electrostatic adsorption interaction between the dual positively charged sites of TPE-Py-FP and the negatively charged triphosphate structure of ATP. Additionally, TPE-Py-FP could localize in mitochondria specifically with a Pearson's coefficient of 0.81, and show great utility in monitoring the fluctuation of mitochondrial ATP level.