An easily available camphor-derived ratiometric fluorescent probe with AIE feature for sequential Ga3+ and ATP sensing in a near-perfect aqueous media and its bio-imaging in living cells and mice

In this work, an easily available fluorescent probe CPD with aggregation-induced emission (AIE) feature based on natural and renewable camphor was designed and synthesized via a simple Schiff-base reaction between diaminomaleonitrile and the newly synthesized fluorophore CP-CHO. The probe CPD could selectively sense Ga3+ over other metal ions (including Al3+ and In3+) through a ratiometric strategy, which was realized for the first time. Moreover, this Ga3+-specific probe was operable in a near-perfect aqueous solution, thereby holding promise for biology-related applications. After chelation with Ga3+ , the in situ generated CPD-Ga3+ (1:1) ensemble was subsequently employed as a selective fluorescent probe for ratiometric recognition of ATP over other anions. The probe CPD also displayed ultrafast and reversible fluorescence responses toward Ga3+ and ATP with low detection limits. Furthermore, a simple test strip-based portable detecting device and a combinatorial molecular logic circuit were established for improving its practical applicability. Additionally, the desirable sensing performances of CPD for Ga3+ and CPD-Ga3+ complex for ATP were successfully reconfirmed both in living HeLa cells and in living mice.