SO2 In Cells Research Articles

Dual-channel fluorescent probe for detecting SO2 and Hg2+, and dynamic imaging SO2 under Cd2+ in alfalfa (Medicago sativa)

BackgroundAs an antioxidant, SO2 plays a critical role in maintaining the plant's redox balance. At the same time, Hg2+ as heavy metals, will accumulate in plants through soil, often disrupting physiological processes in plants. However, few studies have been reported to examine changes in Hg2+ and SO2 in plants. Here, we developed a dual-channel fluorescent probe NYD, which can differentiate between the detection of Hg2+ and SO2. ResultsThe probe exhibits high sensitivity (LOD, 44 nM for Hg2+ and 26 nM for SO2). When Hg2+ and HSO3− deprotect and attack the double bond by nucleophilic addition, significant emission of fluorescence at 475 nm and 574 nm with blue and red fluorescence respectively. In addition, NYD has the capability to detect the levels of Hg2+ and SO2 in cells and alfalfa seedlings. Meanwhile, the findings indicated that alfalfa seedlings were exposed to Cd2+, which led to redox imbalance and increased endogenous SO2 production. SignificanceWe anticipate that this research will contribute to a better understanding of the functions of SO2 under oxidative stress induced by Cd2+.

Real time precisely tracing the fluctuations of mitochondrial SO2 in cells during ferroptosis and tissues using a mitochondrial-immobilized ratiometric fluorescent probe

Mitochondrial sulfur dioxide (SO2) plays important roles in physiological and pathological activities. Unfortunately, it is lack of a reliable tool to precisely visualize the mitochondrial SO2 and elaborate its complicated functions in various cytoactivities. Here we report a mitochondrial-immobilized fluorescent probe PM-Cl consisting of coumarin and benzyl chloride modified benzothiazole, which enables selective visualization of mitochondrial SO2via chemical immobilization. The spectral results demonstrated that probe PM-Cl could respond to SO2 with high selectivity and sensitivity. Co-localization and the fluorescence of cytolysis extraction verified the excellent mitochondrial targeting and anchoring abilities. Due to the chemical immobilization, probe PM-Cl could firmly retain into mitochondria after stimulation of carbonyl cyanide m-chlorophenyl hydrazone (CCCP) and H2O2. Significantly, a series of fluorescence images are indicative of capability for detecting the fluctuations of SO2 in mitochondria during ferroptosis. Furthermore, PM-Cl also could visualize SO2 in myocardium and muscle tissues after the stimulation of CCCP. Taken together, probe PM-Cl is a very potential molecular tool for precisely detecting mitochondrial SO2 to explore its complex functions in physiological and pathological activities.

A near-infrared AIE fluorescent probe for accurate detection of sulfur dioxide derivatives and visualization of fingerprints

In most biophysiological processes, sulfur dioxide (SO2) is an important intracellular signaling molecule that plays an important role. The change of SO2 in cells are closely related to various diseases such as neurological disorders and lung cancer, so it is necessary to develop fluorescent probes with the ability to accurately detect SO2 during physiological processes. In this work, we designed and synthesized a multifunctional fluorescent probe TIS. TIS has excellent properties such as near-infrared emission, large stokes shift, excellent SO2 detection capabilities, low detection limit, high specificity and visualization of color change before and after reaction. Simultaneously, TIS has low cytotoxicity, good biocompatibility, clear cell imaging capability and mitochondrial targeting ability. In addition, the ability of TIS to be applied to different material surfaces for latent fingerprint fluorescence imaging was also explored. TIS provides an excellent method for the accurate detection of SO2 derivatives and shows great potential applications in near-infrared cellular imaging and latent fingerprint fluorescence imaging.

A dual-channel fluorescent nanoprobe for accurate cancer diagnosis by sequential detection of adenosine triphosphate and sulfur dioxide

Cancer is one of the major diseases that seriously endanger the health of all mankind. Accurate diagnosis of early cancer is the most promising way to reduce cancer harm and improve patient survival. However, many developed fluorescent probes for cancer imaging only have the function of identifying one marker, which cannot meet the needs of accurate diagnosis. Here, a fluorescent nanoprobe (CPH@ZIF-90) utilizing ZIF-90 to encapsulate SO2-sensitive dye (CPH) is synthesized for the sequential detection of ATP and SO2. The nanoprobe first interacts with ATP to release CPH, thus increasing the fluorescence at 685 nm and realizing the near-infrared (NIR) fluorescence detection of ATP. Then, SO2 acts on the released CPH through nucleophilic addition, affecting the π-conjugated structure of CPH and resulting in enhanced fluorescence at 580 nm. CPH@ZIF-90 exhibits satisfactory sensitivity and selectivity for sequential detection of ATP and SO2. Excitedly, CPH@ZIF-90 can sequentially image the endogenous ATP and SO2 in cells, showing sensitive fluorescence changes in dual channels (red and green). Due to the NIR emission properties of CPH@ZIF-90 and its ability to enrich in tumor, it is applied to monitor ATP and SO2 in mice and distinguish normal mice from tumor mice. The ability of CPH@ZIF-90 to sequentially detect two cancer-related biomarkers makes it provide meaningful assistance in accurate early diagnosis of cancer.

A novel colorimetric and red-emitting fluorescent probe based on benzopyrylium derivatives for selective detection and imaging of SO2 derivatives in cells and zebrafish

Abnormal levels of endogenous sulfur dioxide in organisms will cause cardiovascular, respiratory and neurological diseases. Therefore, the development of an effective detecting method for real-time, quantitative detection of sulfur dioxide derivatives in organisms is of great importance in physiological and pathological aspects. In this work, a red-emitting SO2 fluorescent probe based on benzopyrylium derivatives were designed and synthesized to specifically detect SO2 derivatives by nucleophilic addition of unsaturated carbon-carbon double bonds. The probe is characterized with rapid response, “naked eye” visualization, broad detection range and high sensitivity (8.1 μM) for SO2 derivatives. In addition, it has been applied to track the dynamic, real-time, visual detection of exogenous and endogenous SO2 in cells, and imaging of exogenous SO2 derivatives in zebrafish.

A near-infrared fluorescent probe for ratiometric sensing of SO2 in cells and zebrafish.

Developing suitable molecular tools for monitoring SO2 and its derivatives in living organisms is attractive due to their importance for human health. Herein, the first near-infrared fluorescent probe Mito-HN with aggregation-induced emission enhancement (AIEE) characteristics for ratiometric sensing of SO2 derivatives in vitro, in cells, and in zebrafish was designed and synthesized. By connecting the electron-donating naphthopyran and electron-withdrawing hemicyanine via the alkenyl group, this probe displays a near-infrared fluorescence emission and notable solid-state luminescence with AIEE features. Based on the specific 1,4-addition reaction of HSO3-/SO32- with the C[double bond, length as m-dash]C double bond of Mito-HN, this probe can specifically sense HSO3- in real time with an excellent near-infrared ratiometric fluorescence effect, a low detection limit of 0.17 μM, and a fast response time of less than 30 s. Cell imaging and zebrafish imaging results demonstrate that Mito-HN can ratiometrically not only sense endogenous SO2 derivatives in mitochondria but also monitor SO2 in living organisms. We anticipate that Mito-HN could be applied for the diagnosis of SO2-related diseases in the future.

A FRET-based probe for detection of the endogenous SO2 in cells

Animidazo[1,5-a]pyridine-hemicyanine-based ratiometric fluorescent probe (IPBT-SO2) was designed for sensing sulfites. The detection mechanism is based on Förster resonance energy transfer (FRET). The probe exhibits high selectivity and sensitivity to SO32−, having a detection limit of 70 nM. Furthermore, the probe has been successfully used to image endogenous SO2 in cells.