Construction of NIR and Ratiometric Fluorescent Probe for Monitoring Carbon Monoxide under Oxidative Stress in Zebrafish

Abstract

Carbon monoxide (CO), as a crucial gasotransmitter, is endogenously produced by the degradation of heme and plays a critical role in regulating various physiological and pathophysiological processes such as oxidative stress. Thus, an effective fluorescent probe for investigating the relationships between CO and oxidative stress in vivo is necessary. In this paper, a ratiometric near-infrared (NIR) fluorescent probe (CP-CO) based on a coumarin-benzopyran fluorophore for imaging CO is developed. CP-CO itself displays strong coumarin emission due to its spironolactone structure. After the probe is reacted with CO and PdCl 2 , a notable enhancement of emission intensity at 690 nm can be found, which results in an obvious red shift of emission (200 nm). Moreover, CP-CO exhibits high sensitivity toward CO and produces a high enhancement ratio (203-fold). In addition, the probe is applied for ratiometric monitoring of exogenous and endogenous CO levels in HepG2 cells. Furthermore, the fluorescence imaging of CP-CO in zebrafish is performed by twophoton excitation along with excellent penetration ability. Most importantly, CP-CO can visualize the upregulation of CO under lipopolysaccharide (LPS)-induced oxidative stress in a zebrafish model, which vividly reveals its excellent ability in the elucidation of CO function in related biological events.

Activity‐Based Fluorescent Probes for Sensing and Imaging of Reactive Carbonyl Species (RCSs)

“…Jiang et al developed a coumarin-benzopyran conjugated with a twophoton fluorescent probe CPÀ CO (Figure 10). [114] Releasing of CO, followed by deallylation of the probe, exhibited a ratiometric fluorescence change. Ring-opening of spironolactone led to enhance NIR fluorescence.…”

Natural flavylium-inspired far-red to NIR-II dyes and their applications as fluorescent probes for biomedical sensing

“…The emission wavelength of flavylium-inspired fluorophores can be red-shifted to the NIR region by expanding their p-conjugation (F8-F16). [24][25][26][27][28][29][30][31][32] Among them, coumarin-hybrid flavylium fluorophores are particularly attractive because the extensive p-conjugation of the coumarin skeleton endows flavylium with NIR emission, 33 and a ratiometric fluorescence response is obtained by simultaneously measuring the fluorescence of whole flavylium fluorophores and that of the coumarin unit. Ratiometric fluorescence detection simultaneously records two or more emission bands and calculates their ratio, which can avoid experimental error caused by variability arising from interference factors, including environment conditions (e.g., pH, polarity, viscosity, and temperature), photo bleaching, and an inhomogeneous distribution of probes.…”

Targeted and activatable nanosystem for fluorescent and optoacoustic imaging of immune-mediated inflammatory diseases and therapy via inhibiting NF-κB/NLRP3 pathways

“…Moreover, targeted nanodrugs which can give out indicative signals upon activation by ROS would be an ideal theranostic system for in-situ detection of inflammation-related diseases in a non-invasive manner and for on-demand drug release in the disease site, thereby offering accurate diagnosis and precision treatment. Near infrared (NIR) fluorescence imaging technology has been established as a powerful tool for providing a high degree of sensitivity in biomedical applications due to its attractive properties such as high contrast and sensitivity, low cost, absence of ionizing radiation, ease of use, and high specificity [ [50] , [51] , [52] , [53] , [54] , [55] , [56] ]. Recently, to further improve the performance of the optical imaging, such as the elevation of penetration depth and reduction of tissue scattering, the optoacoustic imaging has emerged as a robust and promising modality for live animal imaging [ [57] , [58] , [59] , [60] , [61] , [62] , [63] ].…”