Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) , Kolkata, Mohanpur, West Bengal 741246, India.
ACS Appl Mater Interfaces. 2015 Nov 25;7(46):25702-8. doi: 10.1021/acsami.5b06730. Epub 2015 Nov 11.
We report a green synthetic approach to the synthesis of water dispersible Ce(3+)/Tb(3+)-doped SrF2 nanocrystals, carried out using environment friendly microwave irradiation with water as solvent. The nanocrystals display strong green emission due to energy transfer from Ce(3+) to Tb(3+) ions. This strong green emission from Tb(3+) ions is selectively quenched upon addition of Cu(2+) ions, thus making the nanocrystals a potential Cu(2+) ions sensing material. There is barely any interference by other metal ions on the detection of Cu(2+) ions and the detection limit is as low as 2 nM. This sensing ability is highly reversible by the addition of ethylenediaminetetraacetic acid (EDTA) with the recovery of almost 90% of the original luminescence. The luminescence quenching and recovery cycle was repeated multiple times without much effect on the sensitivity. The study was extended to real world water samples and obtained similar results. In addition to the sensing, we strongly predict the small size and high luminescence of the Ce(3+)/Tb(3+)-doped SrF2 nanocrystals can be used for bioimaging applications.
我们报告了一种绿色合成方法，用于使用环境友好的微波辐射，以水为溶剂，合成可分散在水中的 Ce(3+)/Tb(3+)-掺杂 SrF2 纳米晶体。纳米晶体由于 Ce(3+)离子向 Tb(3+)离子的能量转移而显示出强烈的绿色发射。当加入 Cu(2+)离子时，Tb(3+)离子的这种强烈的绿色发射会被选择性猝灭，从而使纳米晶体成为一种潜在的 Cu(2+)离子传感材料。其他金属离子对 Cu(2+)离子的检测几乎没有干扰，检测限低至 2 nM。通过加入乙二胺四乙酸（EDTA），这种传感能力具有高度的可逆性，原始发光强度几乎恢复了 90%。该发光猝灭和恢复循环重复多次，对灵敏度几乎没有影响。该研究扩展到实际水样，并得到了类似的结果。除了传感，我们还强烈预测 Ce(3+)/Tb(3+)-掺杂 SrF2 纳米晶体的小尺寸和高发光性可用于生物成像应用。
