Turn-off fluorescence of organic fluorophore, 2-[4-(2H-Naphtho[1,2-d][1,2,3]triazol-2-yl)-phenyl]carboxylic acid (NTPC), with metal ions (Fe3+, Cu2+, Pb2+) was converted into turn-on fluorescent sensor for biologically important Zn2+, Cu2+ and Fe3+ metal ions in aqueous solution at ppb level by exploiting strong fluorescence quenching phenomena of metal nanoparticles when organic fluorophores assembled in the vicinity of metallic surface. Amino acid attached phenolic ligands (L) were used as reducing as well as functional capping agents in the synthesis of silver nanoparticles (AgNPs). The hydrogen bonding functionality of L facilitated the assembling of NTPC in the vicinity of metallic surfaces that leads to complete quenching of NTPC fluorescence. The strong and selective coordination of L with metal ions (Zn2+, Cu2+ and Fe3+) separates the NTPC from the AgNPs surface that turn-on the NTPC fluorescence. HR-TEM and absorption studies confirm the metal coordination with L and separation of NTPC from the AgNPs surface. Mn2+ showed selective red shifting of NTPC fluorescence after 12 h with all sample. Effects of different amino acid attached phenolic ligands were explored in the metal ion sensitivity and selectivity. This approach demonstrates the multifunctional utility of metal NPs in the development of turn-on fluorescence sensor for paramagnetic heavy metal ions in aqueous solution.
有机荧光团 2-[4-(2H-
萘并[1,2-d][1,2,3]三唑-2-基)-苯基]
甲酸 (NTPC) 与
金属离子的关闭荧光当有机荧光团聚集在
金属表面附近时,利用
金属纳米颗粒的强荧光猝灭现象,将(Fe3+、Cu2+、Pb2+)转化为开启荧光传感器,检测
水溶液中 ppb 级的具有
生物学意义的 Zn2+、Cu2+ 和 Fe3+
金属离子。
氨基酸连接的
酚配体 (L) 在
银纳米颗粒 (AgNP) 的合成中用作还原剂和功能性封端剂。 L 的氢键功能促进了 NTPC 在
金属表面附近的组装,从而导致 NTPC 荧光完全猝灭。 L 与
金属离子(Zn2+、Cu2+ 和 Fe3+)的强选择性配位将 NTPC 与 AgNP 表面分开,从而开启 NTPC 荧光。 HR-
TEM 和吸收研究证实了
金属与 L 的配位以及 NTPC 从 AgNPs 表面的分离。 12 小时后,所有样品的 Mn2+ 显示出 NTPC 荧光的选择性红移。探讨了不同
氨基酸连接的
酚配体对
金属离子敏感性和选择性的影响。这种方法证明了
金属纳米粒子在开发
水溶液中顺磁性重
金属离子的开启荧光传感器中的多功能用途。