Na-X@nZVI/Ni loaded schiff base as florescent probe for sequential recognition of Mg²⁺ and HPO₄ ^2- in DMSO

Schiff base functionalized aminated Na-X@ nZVI/Ni P3 is used as florescent probe for detecting metal cations and anions in various solvents. In all the solvent of THF, DMF and DMSO, the probe P3 can detect Mg<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup>. Under these three conditions, the linear ranges are 1.0 μM - 21 μM, 0.5 μM - 22 μM and 0.45 μM - 14.5 μM, respectively. And their respective LODs are 1.62 nM, 1.92 nM and 1.34 nM. Furthermore, the probe P3 can sequentially recognize Mg<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup> and HPO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub><sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2-</sup> in DMSO. The concentration of HPO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub><sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2-</sup> presents piecewise linear relationship with the mixture of P3 and Mg<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2+</sup>. In the two ranges of 1.0 μM - 34 μM and 79 μM - 165 μM, the respective LODs of HPO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub><sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2-</sup> are 7.68 nM and 49.9 nM. The probe P3 shows relative high sensitivity, and the LODs for the identified ions are as low as the order of magnitude nM. Meanwhile, the probe P3 bears the characteristic of quick response, and the response time is within 1 min. Identification mechanisms of probe P3 for various cations and HPO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub><sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2-</sup> are also studied.