Synthesis and Application of Benzimidazole-Carbazole-based Fluorescent Probe for Detection of Phosgene
10.19756/j.issn.0253-3820.251196
- VernacularTitle:用于光气检测的苯并咪唑-咔唑基荧光探针的合成及应用
- Author:
Guang-Mei XU
1
;
Ze-Yu SONG
;
Qin-Qin TIAN
;
Xiao-Hong ZHU
;
Jin-Chao SHEN
;
Wei HE
Author Information
1. 空军军医大学药学系,西安 710032;空军军医大学基础医学院学员一大队三队,西安 710032
- Keywords:
Fluorescent probe;
Phosgene;
Visual detection;
Smartphone
- From:
Chinese Journal of Analytical Chemistry
2025;53(10):1705-1713,中插37-中插41
- CountryChina
- Language:Chinese
-
Abstract:
Phosgene is a highly reactive chemical substance and a prevalent chemical warfare agent,and it is vitally important for rapid and accurate detection of phosgene to counteract terrorist threats and industrial accidents.In this work,a phosgene probe,designated as SX-Pho,which incorporated benzimidazole and hydroxyl groups as recognition motifs,was prepared through Suzuki coupling and Debus-Radziszewski methodologies to incorporate an electron-donating carbazole moiety.This probe exhibited a large Stokes shift(Approximately 130 nm).Upon exposure to triphosgene/triethylamine conditions(in situ phosgene generation),the fluorescence emission of probe at 470 nm underwent significant quenching,with a 20-fold reduction in intensity,while the fluorescence lifetime decreased from 3.30 ns to 3.06 ns.Concentration titration experiments demonstrated that SX-Pho achieved a lower detection limit of 57.8 nmol/L with high specificity and interference resistance.Preton nuclear magnetic resonance spectroscopy(1H NMR),high-resolution mass spectrometry,and density functional theory(DFT)calculations confirmed the cyclization reaction between hydroxyl groups,imines,and phosgene.The extent of overlap between the highest occupied molecular orbital(HOMO)and the lowest unoccupied molecular orbital(LUMO)was notably decreased,leading to the suppression of radiative transitions.The energy gap underwent a reduction of 0.43 eV,while the non-radiative transition was augmented,resulting in fluorescence quenching and achieving rapid detection of phosgene.Based on this,probe-loaded test strips were prepared.The color change under 365 nm illumination allowed visual discrimination of phosgene at concentrations below 20 μL/L.Furthermore,using a smartphone's built-in RGB application to measure the intensity of the blue(B)channel after the test strips were exposed to phosgene enabled both qualitative and quantitative detection.The detection range was 1.82-50 μL/L,with a limit of detection(LOD)of 1.814 μL/L.
