A neoteric smartphone-assisted colorimetric and fluorometric dual-mode probe based on anthraquinone derived Schiff base for wide-range pH and Cu2+/S2-determination in bioimaging

The fluctuation of ion content has an important effect on human health and ecological environment. Herein, a novel colorimetric and fluorescent dual mode probe ( DMHB ) has been designed via the imine bond bridging of anthraquinone derivative dye and salicyl hydrazide. The DMHB displays significance wide-range pH dependent spectral behavior (pKa 5.07), which is based on proton dissociation reaction on phenol hydroxyl group. By combining with smartphone, DMHB can be utilized as an outstanding visual sensor for the on-site detection of H+. Furthermore, DMHB demonstrates a particular response to Cu2+ and S 2- accompanied by a naked-eye color and fluorescence change. Importantly, DMHB allowed for accurate quantification of wide-range pH, combined with smartphones, to build a sensing platform for the detection of pH for biomedical and environmental analysis. Hence, DMHB not only provides a powerful tool for effectively differentiating tumor cells from normal cells, but also provides valuable insights for the development of imaging H+ fluctuations and Cu2+/S2- in different bioorganisms, thereby showcasing the exceptional capabilities of probe in environmental and bioimaging.