A water-stable phosphorescent probe for doxorubicin detection by phosphorescence resonance energy transfer

Phosphorescent sensing probes have attracted considerable attention due to their ability to eliminate autofluorescence interference in biological samples. However, constructing water-stable phosphorescent materials remains a significant challenge because of water-quenched phosphorescence (phos.) property. Herein, a facile one-step thermal polymerization is proposed to synthesize aluminium/4-chlorobenzoicacid phosphorescent materials (Al/PCBA-PMs). The obtained Al/PCBA-PMs have two phos. emissions at 438 nm and 515 nm, respectively, with a lifetime of 83.67 ms. Importantly, the Al/PCBA-PMs show good water-stable phosphorescent property, and the introduction of water can cause a change in phosphorescent color of Al/PCBA-PMs from blue to green, but which has only a small impact on phosphorescent intensity and lifetime. Furthermore, a system of phos. resonance energy transfer (PhRET) can be constructed where Al/PCBA-PMs act as phosphorescent donors and doxorubicin (DOX) serves as fluorescent acceptors. This PhRET system has a high efficiency of 44.25 %, which can achieve the direct and precise determination of DOX in biological samples with strong autofluorescence, with a linear range of 0 −100 μM. This work proposes a powerful strategy for constructing water-stable phosphorescent probes and develops a new type of PhRET system to achieve precise phosphorescent detection in biological samples.