Research Institute of Applied Catalysis, School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China.
Research Institute of Applied Catalysis, School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China.
Anal Chim Acta. 2019 Nov 8;1080:196-205. doi: 10.1016/j.aca.2019.07.023. Epub 2019 Jul 12.
Since inorganic phosphate ion (PO) plays very important roles in environment or living organisms, developing a selective and sensitive detection method for PO is highly desired. Owing to the superior optical properties, graphene quantum dots (GQDs) have been developed as a promising emitting material in fluorescence analysis. Herein, we reported the first example of negatively charged molybdate-mediated nitrogen doped graphene quantum dots (MoO-mediated N-GQDs) as a fluorescence "off-on" probe for POvia "anion ion-mediated" strategy. The N-GQDs was firstly modified with MoO through a complex bonding system containing ionic and hydrogen bonds. The formation of N-GQDs/MoO complex leaded to photoluminescence (PL) quenching of N-GQDs. In the presence of PO, strong affinity between PO and MoO produced ammonium phosphomolybdate, which destroyed the pre-formed N-GQDs/MoO structure and detached MoO from N-GQDs surface. Thus, the PL of N-GQDS was in turn switched on. Under optimal conditions, this probe exhibited a good linear relationship between PL response and PO concentration in the range from 7.0 to 30.0 μM with a limit of detection of 50 nM. Also this probe with high selectivity and sensitivity has been successfully used to sense PO in natural water, biological fluid, and living cells.
由于无机磷酸离子 (PO) 在环境或生物体内起着非常重要的作用，因此开发一种对 PO 具有选择性和灵敏度的检测方法是非常需要的。由于具有优异的光学性能，石墨烯量子点 (GQDs) 已被开发为荧光分析中一种有前途的发光材料。在此，我们首次报道了带负电荷的钼酸盐介导氮掺杂石墨烯量子点 (MoO 介导的 N-GQDs) 通过“阴离子离子介导”策略作为 PO 的荧光“关-开”探针的实例。N-GQDs 首先通过含有离子键和氢键的复杂键合系统与 MoO 进行修饰。N-GQDs/MoO 配合物的形成导致 N-GQDs 的光致发光 (PL) 猝灭。在 PO 的存在下，PO 和 MoO 之间的强亲和力产生了磷钼酸铵，从而破坏了预先形成的 N-GQDs/MoO 结构并将 MoO 从 N-GQDs 表面脱离。因此，N-GQDS 的 PL 随之打开。在最佳条件下，该探针在 7.0 至 30.0 μM 的范围内，PL 响应与 PO 浓度之间呈现出良好的线性关系，检测限为 50 nM。该探针还具有高选择性和灵敏度，已成功用于检测天然水、生物体液和活细胞中的 PO。
