Selective Detection of Hg²⁺ Ions with Boron Dipyrromethene‐Based Fluorescent Probes Appended with a Bis(1,2,3‐triazole)amino Receptor

Abstract

By using a copper‐promoted alkyne–azide cycloaddition reaction, two boron dipyrromethene (BODIPY) derivatives bearing a bis(1,2,3‐triazole)amino receptor at the meso position were prepared and characterized. For the analogue with two terminal triethylene glycol chains, the fluorescence emission at 509 nm responded selectively toward Hg2+ ions, which greatly increased the fluorescence quantum yield from 0.003 to 0.25 as a result of inhibition of the photoinduced electron transfer (PET) process. By introducing two additional rhodamine moieties at the termini, the resulting conjugate could also detect Hg2+ ions in a highly selective manner. Upon excitation at the BODIPY core, the fluorescence emission of rhodamine at 580 nm was observed and the intensity increased substantially upon addition of Hg2+ ions due to inhibition of the PET process followed by highly efficient fluorescence resonance energy transfer (FRET) from the BODIPY core to the rhodamine moieties. The Hg2+‐responsive fluorescence change of these two probes could be easily seen with the naked eye. The binding stoichiometry between the probes and Hg2+ ions in CH3CN was determined to be 1:2 by Job′s plot analysis and 1H NMR titration, and the binding constants were found to be (1.2±0.1)×1011 m−2 and (1.3±0.3)×1010 m−2, respectively. The overall results suggest that these two BODIPY derivatives can serve as highly selective fluorescent probes for Hg2+ ions. The rhodamine derivative makes use of a combined PET‐FRET sensing mechanism which can greatly increase the sensitivity of detection.

Photonics of Halogenated Zinc(II) and Cadmium(II) Dipyrromethene Complexes

“…It is also known that dipyrromethene complexes are used as active media for fluorescent markers and probes [10][11][12]. Moreover, derivatives of dipyrromethene complexes are potential sensors for detection of metal ions such as Pb(II), Hg(II), Pt(II) and gases in an air mixture (COCl2,CO2, COS, SO2 and SO3) [13][14][15][16][17][18]. Such sensors are used in the areas of biological and medical research.…”

“…Colorants 2022, 1 299 Hg(II), Pt(II) and gases in an air mixture (COCl 2 ,CO 2 , COS, SO 2 and SO 3 ) [13][14][15][16][17][18]. Such sensors are used in the areas of biological and medical research.…”

Research Progress in Mercury Ion Fluorescence Probes Based on Organic Small Molecules

“…+ EtOH 利于增强荧光性能 [42] , 且其含有多个 N 原子与 Hg 2 ＋ 配 位, 能作为 Hg 2 ＋ 的识别单元, 故 BODIPY-三唑组合作为 Hg 2 ＋ 检测荧光探针也有报道 [43] . 例如, Kiatisevi 课题 组 [44] 通过在邻苯二酚单元上桥接两个 BODIPY 荧光团/ 三唑结合基团单元构建了探针 5 (Eq.…”

“…当探针分子与 Hg 2 ＋ 配位后, 配合物的 ICT 过程会受到抑 制, 探针分子本身的荧光发射减弱或消失的同时出现蓝 移的荧光增强 [93] . 例如, 史文静课题组 [94] 合成了含双三 唑结构的 BODIPY 基近红外探针 15 (Eq. 10), 其多个 N 原子与两个 Hg 2 ＋ 配位后, N 原子到 BODIPY 核的 ICT 过 程被有效抑制, 荧光发生强烈的蓝移和增强, 溶液颜色 由绿色变为蓝绿色, 可裸眼检测 Hg 2 ＋ .…”

Ion recognition by 1,2,3‐triazole moieties synthesized via “click chemistry”

“…[ 252 ] Shi group synthesized bodipy‐based 1,2,3‐triazole probe (Table 3c) that exhibited substantial enhancement in fluorescence emission at 580 nm on addition of Pb 2+ ions attributing to PET inhibition. [ 253 ] Vedamalai and Wu reported bodipy‐based 1,2,3‐triazole chemosensor (Table 3c) that displayed fluorescence enhancement on addition of Hg 2+ ions along with visual changes from red to yellow. [ 254 ] Wu group presented the synthesis of a conjugated polymer sensor for fluorescent recognition of Hg 2+ by exhibiting quenching in fluorescence and disappearance of color under UV light on incremental Hg 2+ addition.…”