Carbon Monoxide In Living Cells Research Articles

A Nuclear-Localized Naphthalimide-Based Fluorescent Light-Up Probe for Selective Detection of Carbon Monoxide in Living Cells.

A nuclear-localized fluorescent light-up probe, NucFP-NO2, was designed and synthesized that can detect CO selectively in an aqueous buffer (pH 7.4, 37 °C) through the CO-mediated transformation of the nitro group into an amino-functionalized moiety. This probe triggered a more than 55-fold "turn-on" fluorescence response to CO without using any metal ions, e.g., Pd, Rh, Fe, etc. The enhanced response is highly selective over a variety of relevant reactive oxygen, nitrogen, and sulfur species and also various biologically important cationic, anionic, and neutral species. The detection limit of this probe for CO is as low as 0.18 μM with a linear range of 0-70 μM. Also, this fluorogenic probe is an efficient candidate for monitoring intracellular CO in living cells (RAW 264.7, A549 cells), and the fluorescence signals predominantly localize in the nuclear region.

Self-Assembled Fluorescent Nanoprobe Based on Forster Resonance Energy Transfer for Carbon Monoxide in Living Cells and Animals via Ligand Exchange.

Carbon monoxide (CO) is recognized as a biologically essential gaseous neurotransmitter that modulates many physiological processes in living subjects. Currently reported fluorescent probes for CO imaging in cells basically utilize palladium related chemistry which requires complicated synthetic work. Herein we provide a new strategy to construct a fluorescent nanoprobe, NanoCO-1, based on the Forster resonance energy transfer (FRET) mechanism by entrapping the existing dirhodium complex as the energy acceptor and the CO recognition part, and a commonly used nitrobenzoxadiazole (NBD) dye as energy donor into a micelle formed by self-assembly. The exchange of ligands in the dirhodium complex by CO in the nanoprobe disrupts the FRET and leads to the turn-on of fluorescence. The merits of NanoCO-1 including good biocompatibility, selectivity, photostability, and low cytotoxity, render this nanoprobe ability to track CO in living cells, zebrafish embryo, and larvae. Our straightforward approach can be extended to establish the CO fluorescent probes based on adsorption of CO on a variety of metal derivatives.

Bioluminescence Imaging of Carbon Monoxide in Living Cells and Nude Mice Based on Pd0-Mediated Tsuji-Trost Reaction.

Carbon monoxide (CO) is highly toxic and lethal to humans and animals because of its strong affinity for hemoglobin, while this "silent killer" is constantly generated in the body as a cell-signaling molecule of the gasotransmitter family in various pathological and physiological conditions. Up to now, designing fluorescent probes for real-time imaging of CO in living species is a continuous challenge due to background interference, light scattering, and photoactivation/photobleaching. Herein, a novel type of bioluminescence probe (allyl-luciferin) was synthesized and exploited to realize CO imaging with high signal-to-noise ratios. Based on Pd0-mediated Tsuji-Trost reaction, allyl-luciferin specifically reacted with CO to yield D-luciferin and thus generate a turn-on bioluminescence response, exhibiting high selectivity against bioactive small molecules such as reactive nitrogen, oxygen, and sulfur species. Furthermore, the new probe can be easily employed to detect exogenous CO in Huh7 cells and MDA-MB-231 cells, and CO production was enhanced greatly in these living cells after pretreatment with [Ru(CO)3Cl-(glycinate)] (CORM-3). Through the use of PdCl2-containing liposomes to improve poor membrane permeability of PdCl2, endogenous CO stimulated by heme was also seen clearly. In addition, the probe was successfully used to monitor exogenous and endogenous CO in nude mice. Overall, our data proved that the allyl-luciferin is a promising tool for exogenous and endogenous CO detection and imaging within living species. This is the first demonstration of bioluminescence imaging obtained by a probe for CO. We anticipate that the good imaging properties of allyl-luciferin presented in this study will provide a potentially powerful approach for illuminating CO functions in the future.

Highly selective detection of carbon monoxide in living cells by palladacycle carbonylation-based surface enhanced Raman spectroscopy nanosensors.

A novel nanosensor was explored for the highly selective detection of intracellular carbon monoxide (CO) by surface enhanced Raman spectroscopy (SERS) on the basis of palladacycle carbonylation. By assembling new synthesized palladacycles (PC) on the surface of gold nanoparticles (AuNPs), SERS nanosensors (AuNP/PC) were prepared with good SERS activity and reactivity with CO. When the AuNP/PC nanosensors were incubated with a CO-containing system, carbonylation of the PC assembled on AuNPs was initiated, and the corresponding SERS spectra of AuNP/PC changed significantly, which allowed the carbonylation reaction to be directly observed in situ. Upon SERS observation of CO-dependent carbonylation, this SERS nanosensor was used for the detection of CO under physiological conditions. Moreover, benefiting from the specificity of the reaction coupled with the fingerprinting feature of SERS, the developed nanosensor demonstrated high selectivity over other biologically relevant species. In vivo studies further indicated that CO in normal human liver cells and HeLa cells at concentrations as low as 0.5 μM were successfully detected with the proposed SERS strategy, demonstrating its great promise for the analytical requirements in studies of physiopathological events involved with CO.

A Reaction-Based Fluorescent Probe for Selective Imaging of Carbon Monoxide in Living Cells Using a Palladium-Mediated Carbonylation

Carbon monoxide is a member of the gasotransmitter family, which also includes NO and H(2)S, and has been implicated in a variety of pathological and physiological conditions. Whereas exogenous therapeutic additions of CO to tissues and whole animals have been well-studied, the real-time spatial and temporal tracking of CO at the cellular level remains an open challenge. Here we report a new type of turn-on fluorescent probe for selective CO detection based on palladium-mediated carbonylation reactivity. CO Probe 1 (COP-1) is capable of detecting CO both in aqueous buffer and in live cells with high selectivity over a range of biologically relevant reactive small molecules, providing a potentially powerful approach for interrogating its chemistry in biological systems.