Cyanine‐Dyad Molecular Probe for the Simultaneous Profiling of the Evolution of Multiple Radical Species During Bacterial Infections

Abstract

Real-time monitoring of the evolution of bacterial infection-associated multiple radical species is critical to accurately profile the pathogenesis and host-defense mechanisms. Here, we present a unique dual wavelength nearinfrared (NIR) cyanine-dyad molecular probe (HCy5-Cy7) for simultaneous monitoring of reactive oxygen and nitrogen species (RONS) variations both in vitro and in vivo. HCy5-Cy7 specifically turns on its fluorescence at 660 nm via superoxide or hydroxyl radical (O 2 C À , COH)-mediated oxidation of reduced HCy5 moiety to Cy5, while peroxynitrite or hypochlorous species (ONOO À , ClO À )-induced Cy7 structural degradation causes the emission turn-off at 800 nm. Such multispectral but reverse signal responses allow multiplex manifestation of in situ oxidative and nitrosative stress events during the pathogenic and defensive processes in both bacteriainfected macrophage cells and living mice. Most importantly, this study may also provide new perspectives for understanding the bacterial pathogenesis and advancing the precision medicine against infectious diseases.

HClO‐Activated Near‐Infrared Fluorogenic Aza‐BODIPY‐Bisferrocene Triad with High Turn‐on Ratio for In Vivo Biosensing

“…[ 9 ] Although near‐infrared (NIR; 700–1700 nm) fluorescence has been validated for high contrast imaging in complex tissue environment, [ 10 ] NIR fluorescent probes that specifically response toward ClO – with high turn‐on ratio remain rare. [ 11 ] A substantial challenge manifest in this issue is the regulation of fluorescence “off” state, because a low and stable basal fluorescence (Fl off ) is critical to ensure high selective turn‐on ratio (Fl on /Fl off ). This is of particular concern when fluorescence boundary (Fl on ) and chemical stability of NIR fluorophores are set lower by the reduced energy gap of frontier molecular orbital (FMO).…”

Recent Progress in Small‐Molecule Fluorescence and Photoacoustic Dual‐Modal Probes for the In‐Vivo Detection of Bioactive Molecules

“…Recently, fluorescence imaging has been developed and recognized as one of the most effective tools for studying molecular events in biological systems owing to its excellent merits in high temporal and spatial resolution [13–16] . However, its application is restricted by the depth of penetration [17] .…”

“…Recently, fluorescence imaging has been developed and recognized as one of the most effective tools for studying molecular events in biological systems owing to its excellent merits in high temporal and spatial resolution. [13][14][15][16] However, its application is restricted by the depth of penetration. [17] Fortunately, the emerging photoacoustic (PA) technology possesses in-depth tissue imaging properties that can well compensate for the deficiency of fluorescence imaging.…”

Dual-Channel Imaging of Amyloid-β Plaques and Peroxynitrite To Illuminate Their Correlations in Alzheimer’s Disease Using a Unimolecular Two-Photon Fluorescent Probe

“…30 We expected that the unimolecular probe with dual-color fluorescence responses could effectively overcome the above obstacle. 31,32 However, as far as we know, such an ideal fluorescent probe has not yet been reported. In particular, twophoton fluorescent probes are preferred for live cell and tissue imaging.…”

“…James and co-workers pioneeringly developed a unimolecular probe, which enabled simultaneous imaging of Aβ plaques and ONOO – , however through the same fluorescence channel . We expected that the unimolecular probe with dual-color fluorescence responses could effectively overcome the above obstacle. , However, as far as we know, such an ideal fluorescent probe has not yet been reported. In particular, two-photon fluorescent probes are preferred for live cell and tissue imaging. , Two-photon microscopy with near-infrared laser irradiation allows focal point excitation and offers three-dimensional images with superior spatial resolution and the merits of deep tissue penetration and limited photobleaching and photodamage.…”