Department of Applied Chemistry, College of Applied Science and Institute of Natural Sciences, Kyung Hee University , Gyeonggi 446-701, Korea.
ACS Appl Mater Interfaces. 2016 May 4;8(17):10946-53. doi: 10.1021/acsami.6b03703. Epub 2016 Apr 25.
The excitation of the adsorbed vanadate group led to the red emission arising from the efficient energy transfer to Eu-doped layered gadolinium hydroxide (LGdH:Eu). This light-harvesting antenna effect allowed LGdH:Eu to detect selectively a vanadate in aqueous solution at different pHs. Because vanadate exists in various forms by extensive oligomerization and protonation reactions in aqueous solution depending on pH, it is important to detect a vanadate regardless of its form over a wide pH range. In particular, spacer molecules with long alkyl chains greatly facilitated access of a vanadate antenna into the interlayer surface of LGdH:Eu. The concomitant increase in adsorption capacity of LGdH:Eu achieved a strong antenna effect of vanadate on the red emission from Eu(3+). When a suspension containing LGdH:Eu nanosheets (1.0 g/L) was used, the vanadate concentration down to 1 × 10(-5) M could even be visually monitored, and the detection limit based on the (5)D0 → (7)F2 emission intensity could reach 4.5 × 10(-8) M.
吸附的钒酸盐基团的激发导致了来自 Eu 掺杂层状氢氧化钆 (LGdH:Eu) 的高效能量转移的红色发射。这种光收集天线效应使得 LGdH:Eu 能够在不同 pH 值的水溶液中选择性地检测钒酸盐。由于钒酸盐在水溶液中通过广泛的聚合和质子化反应以各种形式存在，因此无论其形式如何，在宽 pH 范围内检测钒酸盐都很重要。特别是具有长烷基链的间隔分子极大地促进了钒酸盐天线进入 LGdH:Eu 的层间表面。LGdH:Eu 的吸附容量的同时增加实现了钒酸盐对 Eu(3+) 的红色发射的强天线效应。当使用含有 LGdH:Eu 纳米片（1.0 g/L）的悬浮液时，甚至可以目视监测到浓度低至 1×10(-5) M 的钒酸盐，并且基于（5）D0 →（7）F2 发射强度的检测限可以达到 4.5×10(-8) M。
