<p>Elevated hypochlorous acid (HOCl) levels are closely associated with the onset and progression of inflammatory joint diseases, highlighting the need for imaging probes capable of rapid and accurate HOCl detection in complex biological environments. However, most small-molecule organic fluorescent probes suffer from small Stokes shifts (&lt;100 nm) and severe spectral overlap with excitation light and tissue autofluorescence, which limits their performance <i>in vivo</i>. Here we report an Ir(III) complex-based luminescent probe, Ir-COOH, featuring a large Stokes shift. In aqueous media, Ir-COOH shows an absorption maximum at <i>ca.</i> 540 nm and an emission maximum at <i>ca.</i> 710 nm, corresponding to a Stokes shift of <i>ca.</i> 170 nm, thereby minimizing self-absorption and background interference. Ir-COOH responds to HOCl with fast signal turn-off, high sensitivity (limit of detection: 148.61 nmol/L), excellent selectivity over other reactive species, and good stability across physiologically relevant pH values. Cell experiments indicate low cytotoxicity, and HOCl can be visualized in paraformaldehyde-fixed ATDC5 <i>via</i> luminescence quenching. Moreover, Ir-COOH enables <i>in vivo</i> imaging of endogenous HOCl in a λ-carrageenan-induced mouse arthritis model, providing a sensitive tool for studying HOCl-associated inflammatory arthritis.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

A Large-Stokes-shift Iridium(III) Complex-based Hypochlorous Acid Probe for In vivo Imaging of Inflammatory Arthritis

  • Xinru Hu,
  • Wanxin Liu,
  • Xiaoqiang Wang,
  • Shuxin Peng,
  • Bolin Ji,
  • Peng Wei,
  • Zhijun Guo

摘要

Elevated hypochlorous acid (HOCl) levels are closely associated with the onset and progression of inflammatory joint diseases, highlighting the need for imaging probes capable of rapid and accurate HOCl detection in complex biological environments. However, most small-molecule organic fluorescent probes suffer from small Stokes shifts (<100 nm) and severe spectral overlap with excitation light and tissue autofluorescence, which limits their performance in vivo. Here we report an Ir(III) complex-based luminescent probe, Ir-COOH, featuring a large Stokes shift. In aqueous media, Ir-COOH shows an absorption maximum at ca. 540 nm and an emission maximum at ca. 710 nm, corresponding to a Stokes shift of ca. 170 nm, thereby minimizing self-absorption and background interference. Ir-COOH responds to HOCl with fast signal turn-off, high sensitivity (limit of detection: 148.61 nmol/L), excellent selectivity over other reactive species, and good stability across physiologically relevant pH values. Cell experiments indicate low cytotoxicity, and HOCl can be visualized in paraformaldehyde-fixed ATDC5 via luminescence quenching. Moreover, Ir-COOH enables in vivo imaging of endogenous HOCl in a λ-carrageenan-induced mouse arthritis model, providing a sensitive tool for studying HOCl-associated inflammatory arthritis.