With these results in hand, we further checked the traceability of NPDM to monitor Al 3+ in live HeLa cells (Fig. ). Firstly, the Hela cells treated with NPDM alone showed no fluorescence signal in the green channel, while Hela cells were pre-incubated with NPDM and co-cultured with ascending Al 3+ , and the increasing green fluorescence signals were observed (Fig. ). Thus, the above cell imaging results showed that NPDM could monitor Al 3+ in living cells with favourable cell penetrability and sufficient sensitivity. To further verify the recyclability of NPDM in living biosamples, another fluorescence-imaging experiments were carried in HeLa cells (Fig. ). As the cells were treated with only NPDM, there were no any fluorescence signal in the green channel. When HeLa cells were further treated with 2 equivalent Al 3+ , the bright green fluorescence was observed. Furthermore, addition of the 4 equivalent F -quenched the green fluorescence. Attractively, followed by addition of the excessive Al 3+ (appr. 80 μM) restored the intense green fluorescence (Fig. ). The alterations of intracellular fluorescence was in good accordance with the phenomena in solution. The above phenomena showed that tweezers NPDM can act as a reliable tool to sequentially monitor Al 3+ and F -level in live cells, revealing reversible imaging property of tweezers NPDM in living cells.