Colorimetric and fluorescent chemosensor for highly selective and sensitive relay detection of Cu 2+ and H 2 PO 4 - in aqueous media.

In this manuscript, a new colorimetric and fluorescent chemosensor (T) was designed and synthesized, it could successively detect Cu2+ and H2 PO4 - in DMSO/H2 O (v/v=9:1, pH=7.2) buffer solution with high selectivity and sensitivity. When added Cu2+ ions into the solution of T, it showed a color changes from yellow to colorless, meanwhile, the green fluorescence of sensor T quenched. This recognition behavior was not affected in the presence of other cations, including Hg2+ , Ag+ , Ca2+ , Co2+ , Ni2+ , Cd2+ , Pb2+ , Zn2+ , Cr3+ , and Mg2+ ions. More interestingly, the Cu2+ ions contain sensor T solution could recover the color and fluorescence upon the addition of H2 PO4 - anions in the same medium. And other surveyed anions (including F- , Cl- , Br- , I- , AcO- , HSO4 - , ClO4 - , CN- and SCN- ) had nearly no influence on the recognition behavior. The detection limits of T to Cu2+ and T-Cu2+ to H2 PO4 - were evaluated to be 1.609×10-8 M and 0.994×10-7 M, respectively. In addition, the sensor T also could be served as a recyclable component and the logic gate output was also defined in sensing materials. The test strips based on sensor T were fabricated, which acted as a convenient and efficient Cu2+ and H2 PO4 - test kits.