Rapid Response Fluorescence Probe Enabled In Vivo Diagnosis and Assessing Treatment Response of Hypochlorous Acid‐Mediated Rheumatoid Arthritis

Abstract

Diagnosis and early assessment of the treatment response of rheumatoid arthritis (RA) necessitates a reliable bioanalytical method for rapid, sensitive, and specific detection of the hypochlorous acid (HOCl) biomarker in inflammatory diseases. Herein, two fluorescence probes, Probe‐1 and Probe‐2 are developed for quantitative monitoring and visualization of inflammatory response–related HOCl levels in vitro and in vivo. In the presence of HOCl, fluorescence “OFF–ON” response is obtained for both the probes as a result of specific HOCl‐triggered C=N bond cleavage reaction. Probe‐1 and Probe‐2 feature rapid response (<4 s), a high degree of sensitivity and selectivity toward HOCl, which allow them to be used for quantification of HOCl in a simulated physiological condition. Using Probe‐2 as the probe, fluorescence imaging and flow cytometry analysis of HOCl levels in lysosome of inflammatory mimic cells, visualization of HOCl generation in endotoxin‐induced inflammation of adult zebrafish and RA of mice are possible. Probe‐2 exhibits high effectiveness for early assessment of the treatment response of HOCl‐mediated RA in mice with an antiarthritic drug, methotrexate (MTX). The results demonstrate that Probe‐2 is a powerful tool for future studies on diagnosis and monitoring treatment efficiency in a broad range of inflammatory diseases, including RA.

A Copper (II) Ensemble-Based Fluorescence Chemosensor and Its Application in the ‘Naked–Eye’ Detection of Biothiols in Human Urine

“…And, the fluorescence quantum yields of L-Cu 2+ upon the addition of Cys, Hcy and GSH were calculated to be Φ 3 = 0.33, Φ 4 = 0.39 and Φ 5 = 0.40, respectively. Additionally, a good linearity was found between fluorescence intensity of L-Cu 2+ at 443 nm versus the concentrations of Cys, Hcy and GSH ( Figure S9), and the detection Sensors 2020, 20, 1331 7 of 13 limits were determined to be 0.96 µM, 0.68 µM and 0.44 µM based on 3σ/slope according to reported method [68,69]. Fluorescence responses times of L-Cu 2+ towards biothiols were also discussed in Figure 5D.…”

“…Sensors 2020, 20, x 7 of 13 fluorescence intensity of L-Cu 2+ at 443 nm versus the concentrations of Cys, Hcy and GSH ( Figure S9), and the detection limits were determined to be 0.96 μM, 0.68 μM and 0.44 μM based on 3σ/slope according to reported method [68,69]. Fluorescence responses times of L-Cu 2+ towards biothiols were also discussed in Figure 5D.…”

An LC-MS/MS method for protein detection based on a mass barcode and dual-target recognition strategy

“…1b). 36,37 With the assistance of mass barcodes and sandwiched structure, a sensitive LC-MS/MS method for thrombin determination was successfully established. Under optimized conditions, this method exhibited good stability, high selectivity and excellent sensitivity with a detection limit of 0.007 nM.…”

A Redox-Switchable Colorimetric Probe for “Naked-Eye” Detection of Hypochlorous Acid and Glutathione

“…The reduction–oxidation state of the cell is primarily a consequence of the precise balance between the levels of reactive oxygen species (ROS) and antioxidant [5,6,7,8]. Among these ROS, hypochlorous acid (HOCl) is an endogenous microbicidal agent and a highly potent oxidant that is mainly generated by the catalysis of myeloperoxidase (MPO) in the presence of chloride and hydrogen peroxide under physiological conditions [9,10,11]. Owing to the strong oxidizing effect, HOCl could defend against the invasion of bacteria and regulate the life cycle of the cell [12].…”