A new near-infrared (NIR)-emitting aza-boron-dipyrromethene dye with two electron-donating amino groups at 1- and 7- positions has been prepared via several steps of reactions. This probe showed a NIR absorption at 748 nm with an obvious shoulder peak at 634 nm in CH₃CN/H₂O. Interestingly, a NIR fluorescence emission at 843 nm was observed with a large Stokes shift of 95 nm. This novel NIR-emitting aza-boron-dipyrromethene dye was further investigated as a Hg²⁺-sensing fluorescent probe, which selectively bound to Hg²⁺, showing a blue-shifted and sharp absorption band at 695 nm with the disappearance of the shoulder peak at 634 nm. Correspondingly, the color change could be easily seen from blue to green. Interestingly, the emission exhibited an absolutely “turn-on” peak at 725 nm with a significant blue shift by 118 nm (from 843 to 725 nm), due to the efficient inhibition of the intramolecular-charge-transfer process arising from two amino groups. This probe was finally introduced to Hela cells, showing a “OFF-ON” NIR emission upon exposure to Hg²⁺. The overall results confirmed that this novel NIR-emitting aza-boron-dipyrromethene fluorescent probe with a large Stokes shift could serve as a colorimetric and fluorescent “turn-on” sensor for Hg²⁺ in both solutions and living cells.

通过几个反应步骤，制备了一种新的发射近红外（NIR）的氮杂硼-二吡咯亚甲基染料，该染料在1和7位具有两个供电子氨基。该探针在CH ₃ CN / H ₂ O中显示748 nm的NIR吸收，并在634 nm处出现明显的肩峰。有趣的是，观察到843 nm的NIR荧光发射，斯托克斯位移为95 nm。进一步研究了这种新型的发射NIR的氮杂硼-二吡咯亚甲基染料作为Hg ²⁺传感荧光探针，该探针与Hg ²⁺选择性结合，在695 nm处显示蓝移且尖锐的吸收带，而在634 nm处的肩峰消失。相应地，从蓝色到绿色可以容易地看到颜色变化。有趣的是，由于有效抑制了两个氨基引起的分子内电荷转移过程，因此发射在725 nm处显示了一个绝对的“开启”峰，并发生了118 nm的明显蓝移（从843到725 nm）。 。最终将该探针引入Hela细胞，暴露于Hg ²⁺时显示“ OFF-ON” NIR发射。总体结果证实，这种新型的具有大Stokes位移的发射NIR的氮杂硼-二吡咯亚甲基荧光探针可作为溶液和活细胞中Hg ²⁺的比色和荧光“开启”传感器。