Lysosomal-targeted fluorescent probe based pH regulating reactivity for tracking cysteine dynamics under oxidative stress.

The ability to detect and visualize cellular events and associated biological analytes is essential for the understanding of their physiological and pathological functions. Cysteine (Cys) plays a crucial role in biological systems and lysosomal homeostasis. This puts forward higher requirements on the performance of the probe. Herein, we rationally designed a coumarin-based probe for the reversible, specific, sensitive, and rapid detection of Cys based on pH regulating reactivity. The obtained probe (ECMA) introduces a morpholine moiety to target lysosomes, and α,ß-unsaturated-ketone with an electron-withdrawing CN group served as a reversible reaction site for Cys. Importantly, ECMA was successfully applied to the real-time monitoring of Cys dynamics in living cells. Furthermore, cell imaging clearly revealed that exogenous Cys could induce the up-regulation of lysosomal ROS, which provided a powerful tool for investigating the relationship between oxidative stress and lysosomal Cys.

[Clinical study of optimal positive end-expiratory pressure titration guided by lung stretch index in patients with acute respiratory distress syndrome].

OBJECTIVE: To investigate the clinical practicability of positive end-expiratory pressure (PEEP) titrated by lung stretch index (SI) in patients with acute respiratory distress syndrome (ARDS). METHODS: A parallel randomized controlled trial was conducted. Patients with moderate to severe ARDS who required mechanical ventilation admitted to the department of critical care medicine of General Hospital of the Yangtze River Shipping from August 2022 to February 2023 were enrolled. They were randomly divide into SI guided PEEP titration group (SI group) and pressure-volume curve (P-V curve) inspiratory low inflection point (LIP) guided PEEP titration group (LIP group). All patients were ventilated in a supine position after admission, with the head of the bed raised by 30 degree angle. The primary disease was actively treated, prone position ventilation for 12 h/d, and lung protective ventilation strategies such as controlled lung expansion were used for lung recruitment. On this basis, mechanical ventilation parameters were titrated with SI in the SI group; the LIP group titrated mechanical ventilation parameters with P-V curve inspiratory LIP+2 cmH2O (1 cmH2O≈0.098 kPa). The oxygenation index (PaO2/FiO2), and respiratory mechanics indicators such as lung dynamic compliance (Cdyn), peak airway pressure (Pip) were monitored before recruitment maneuver and after 1, 3, and 5 days of treatment. The therapeutic effect of the two groups was compared. RESULTS: There were 41 patients in the SI group and 40 patients in the LIP group. There was no significant difference in general information such as gender, age, and disease type between the two groups. The mechanical ventilation time and the length of intensive care unit (ICU) stay in the SI group were significantly shorter than those in the LIP group (days: 9.47±3.36 vs. 14.68±5.52, 22.27±4.68 vs. 27.57±9.52, both P < 0.05). Although the 28-day mortality of the SI group was lower than that of the LIP group, the difference was not statistically significant [19.5% (8/41) vs. 35.0% (14/40), P > 0.05]. On the fifth day, the PaO2/FiO2 was higher in SI group [mmHg (1 mmHg≈0.133 kPa): 225.57±47.85 vs. 198.32±31.59, P < 0.05], the Cdyn was higher in SI group (mL/cmH2O: 47.39±6.71 vs. 35.88±5.35, P < 0.01), the Pip was lower in SI group (mmHg: 35.85±5.77 vs. 43.87±6.68, P < 0.05). The Kaplan-Meier survival curve showed no statistically significant difference in the 28 days cumulative survival rate between the two groups (Log-Rank: χ 2 = 2.348, P = 0.125). CONCLUSIONS: The application of SI titration with PEEP in the treatment of ARDS patients may improve their prognosis.

Photoactivation Inducing Multifunctional Coupling of Fluorophore for Efficient Tumor Therapy In Situ.

Photoactivatable molecules, with high-precision spatialtemporal control, have largely promoted bioimaging and phototherapy applications of fluorescent dyes. Here, the first photoactivatable sensor (BI) is described that can be triggered by broad excitation light (405-660 nm), which further undergoes intersystem crossing and H-atom transfer processes to forming superoxide anion radicals (O2 -• ) and carbon radicals. Particularly, the photoinduced gain of carbon-centered radicals (BI•) allows for radical-radical coupling to afford the combined crosslink product (BI─BI), which would be oxidized in the presence of O2 -• to produce an extended conjugate system with near infrared emission (820 nm). Besides, the photochemically generated product (Cy─BI) possesses ultra-high photothermal conversion efficiency up to 90.9%, which optimized phototherapy potential. What's more, Western Blot assay reveals that both BI and the photoproduct Cy─BI can efficiently inhibit the expression of CHK1, and the irradiation of BI and Cy─BI further induces apoptosis and ultimately enhances the phototherapeutic effects. Thus, the combination of cell cycle block inducing apoptosis, photodynamic therapy and photothermal therapy treatments significantly suppress solid tumor in vivo antitumor efficacy explorations. This is a novel finding in developing photoactivatable molecules, as well as the broad applicability of photoimaging and phototherapy in tumor-related areas.

Development of Human Serum Albumin Fluorescent Probes in Detection, Imaging, and Disease Therapy.

Human serum albumin (HSA) acts as a repository and transporter of substances in the blood. An abnormal concentration may indicate the occurrence of liver- and kidney-related diseases, which has attracted people to investigate the precise quantification of HSA in body fluids. Fluorescent probes can combine with HSA covalently or noncovalently to quantify HSA in urine and plasma. Moreover, probes combined with HSA can improve its photophysical properties; probe-HSA has been applied in real-time monitoring and photothermal and photodynamic therapy in vivo. This Review will introduce fluorescent probes for quantitative HSA according to the three reaction mechanisms of spatial structure, enzymatic reaction, and self-assembly and systematically introduce the application of probes combined with HSA in disease imaging and phototherapy. It will help develop multifunctional applications for HSA probes and provide assistance in the early diagnosis and treatment of diseases.

An ICT-switched fluorescent probe for visualizing lipid and HClO in lipid droplets during ferroptosis.

Herein, we have designed and synthesized a fluorescent probe, LDs-ClO, which can detect hypochlorous acid and lipid accumulation simultaneously in lipid droplets of live RAW 264.7 cells. Cell ferroptosis was discovered to lead to an increase in HClO levels, and to possibly further stimulate accumulation of lipid. We expect the results of this work with LDs-ClO to promote the study of physiological and pathological processes related to lipid droplets and hypochlorite.

A summary of calixarene-based fluorescent sensors developed during the past five years.

Calixarenes are "chalice like" phenol-based macrocycles that are one of the most fascinating studied scaffolds in supramolecular chemistry. Their preorganized nonpolar cavities and ion binding sites, and their well-defined conformations all lay important foundations for forming host-guest complexes. Conjugation of calixarene scaffolds with various fluorophores at either upper or lower rims has led to the development of smart fluorescent probes for inorganic molecules or ions, aliphatic or aromatic compounds, biomolecules, temperature and hypoxia, even multi-component traditional Chinese medicine (TCM). Moreover, significant advancements have been made for biological applications. This review critically summarizes the recent advances made in these areas.

A Fluorescent Probe for Investigating the Role of Biothiols in Signaling Pathways Associated with Cerebral Ischemia-Reperfusion Injury.

Cerebral ischemia-reperfusion injury (CIRI) is intimately associated with the redox regulation of biothiol, a crucial antioxidant marker that precludes the onset of ROS. We designed a novel fluorescent probe, DCI-Ac-Py, showing various physicochemical properties, such as high selectivity, exceptional signal-to-noise ratio, near-infrared (NIR) optical window, and blood-brain barrier (BBB) penetrability, for detecting biothiols in the brain. The picolinate serves as a specific recognition group that is rapidly activated by biothiol and undergoes nucleophilic substitution with the adjacent acrylic ester to yield the desired NIR probe. Additionally, the probe's lipid solubility is improved through the inclusion of halogen atoms, which aids in penetrating the BBB. Using DCI-Ac-Py, we investigated changes of biothiols in vivo in the brains of mice during CIRI. We found that biothiol-mediated NF-kB classical (P65-related) and nonclassical (RelB-related) pathways contribute to abundant ROS production induced by CIRI and that biothiols are involved in redox regulation. These findings provide new insights into the study of CIRI and shed light on the physiological and pathological mechanisms of biothiols in the brain.

Serum levels of 25-OH vitamin D levels predict cognitive impairments among acute coronary syndrome patients.

BACKGROUND: The cognitive impairment after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS) has become a crucial clinical concern that cannot be ignored. However, studies on the early warning factors of cognitive impairment after PCI are still insufficient. METHODS: This study reviewed the postoperative cognitive function of 284 patients who underwent PCI in our hospital from June 2019 to June 2022. During the 21-day follow-up, all participants included in the analysis were divided into the cognitive impairment (CI) group (n = 82) and the noncognitive impairment (NCI) group (n = 186) according to their Montreal cognitive assessment (MoCA) scale. Participants' serum 25(OH)D3 levels on admission and serum neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP) and S100ß levels were measured 21 days after surgery. RESULTS: Age more than 65 years, hypertension, operation time longer than 60 min, left ventricular ejection fraction less than 50% and serum 25(OH)D3 less than 31.41 ng/ml were the risk factors for cognitive dysfunction in ACS patients 21 days after PCI. Serum levels of 25(OH)D3, NSE, S100ß and GFAP were significantly higher in patients with cognitive impairment than in patients without cognitive impairment. CONCLUSION: Postoperative serum NSE, S100ß and GFAP levels were significantly negatively correlated with serum 25(OH)D3 levels at admission. The serum 25(OH)D3 level is a risk factor and predictor of cognitive impairment in patients with ACS after PCI.

A nucleophilic addition-elimination based ratiometric fluorescent probe for monitoring N2H4 in biological systems and actual samples.

Hydrazine (N2H4) is an important reagent in the field of fine chemical engineering. However, its accumulation in the environment and food chain could pose a great threat to food safety and human health. Therefore, designing a fluorescent probe with good cell penetration and high selectivity and sensitivity to detect N2H4 in actual samples and in vivo is a meaningful project. Herein, due to the nucleophilicity of hydrazine, we utilized naphthalimide as the fluorescence chromophore and pyrone as the recognition site to achieve the ratiometric detection of hydrazine by ring opening. In addition, we introduced the ester to improve the lipid solubility of the probe, which allowed the probe to better penetrate the cell membrane to realize the fluorescent imaging of probes in cells. Meanwhile, to our delight, the probe showed high selectivity and sensitivity to N2H4 in the test system, so we further applied the probe in water samples and food, in vitro and in vivo.

A near-infrared fluorescent probe for in situ imaging of SO2 flux in drug-induced liver injury.

Sulfur dioxide (SO2) has been widely applied as an important additive in various foods and drugs due to its antioxidant, antiseptic and bleaching properties. SO2 in living organisms plays a key biological role as an antioxidant in a variety of life activities. However, abnormal levels of SO2 in both food and living organisms could cause harm and even serious illness, such as diseases related to the respiratory and cardiovascular systems and cancers. Therefore, it is of great practical significance to accurately determine the level of SO2 in food and organisms. In this work, we synthesized a novel near-infrared ratiometric fluorescent probe (NTO) using xanthene and benzopyran as the matrix for the detection of SO2. NTO demonstrates a rapid response (within 8 s), high selectivity, excellent sensitivity (LOD = 3.64 µM) and a long emission wavelength (800 nm), which could be applied to SO2 monitoring in a complex environment. NTO showed a high recovery (90%-110%) of SO2 in food samples such as beer and rock sugar. The results of HeLa cell experiments indicate that NTO has excellent fluorescence labeling ability for SO2 in endoexogenous-sulfide metabolism. In addition, we applied it to mice with acetaminophen (APAP)-induced acute liver injury and observed changes in SO2 during liver injury. Based on these results, we believe that this will provide a convenient visual tool for the detection of the SO2 content in food safety and biomedicine.

Relationships between blood bone metabolic biomarkers and anemia in patients with chronic kidney disease.

INTRODUCTION: Blood bone metabolic biomarkers are noninvasive indices for evaluating metabolic bone diseases. We investigated the relationships between blood bone metabolic biomarkers and anemia in chronic kidney disease (CKD) patients and analyzed the effects of parathyroidectomy (PTX) on the above indices. METHODS: In this cross-sectional study, 100 healthy controls and 239 CKD patients, including 46 secondary hyperparathyroidism (SHPT) patients with PTX, were enrolled. Moreover, a prospective study was conducted in which 28 PTX patients were followed up. The degree of anemia was classified as mild, moderate, or severe based on the tertiles of hemoglobin (Hb) levels of the anemic CKD patients, with cutoff values of 83 g/L and 102 g/L. Bone metabolic biomarkers, including calcium (Ca), phosphorus (P), intact parathyroid hormone (iPTH), fibroblast growth factor 23 (FGF23), and α-klotho, were tested. RESULTS: The mean estimated glomerular filtration rate (eGFR) in CKD patients was 25.7 ± 36.0 ml/min/1.73 m2, and 84.10% of CKD patients had anemia. The baseline Hb levels in the mild, moderate, and severe anemia subgroups were 110.86 ± 5.99 g/L, 92.71 ± 5.96 g/L, and 67.38 ± 10.56 g/L, respectively. CKD patients had higher adjusted Ca, P, alkaline phosphatase (ALP), iPTH, and FGF23 levels and lower α-klotho levels than controls. Baseline adjusted Ca, P, iPTH, and α-klotho levels were associated with Hb levels in CKD patients. Blood adjusted Ca, P, and iPTH levels were correlated with anemia severity. After PTX (median interval: 6.88 months), anemia and high blood adjusted Ca, P, iPTH, and FGF23 levels were ameliorated, while α-klotho levels were increased. CONCLUSIONS: Blood adjusted Ca, P, iPTH, and α-klotho levels were correlated with Hb levels in CKD patients. Correction of bone metabolic disorders may be a therapeutic strategy for anemia treatment.

An Activatable NIR Fluorescent Probe for NAD(P)H and Its Application to the Real-Time Monitoring of p53 Abnormalities In Vivo.

NAD(P)H is crucial for biosynthetic reactions and antioxidant functions. However, the current probes developed for detecting NAD(P)H in vivo require intratumoral injection, which limited their application for animal imaging. To address this issue, we have developed a liposoluble cationic probe, KC8, which exhibits excellent tumor-targeting ability and near-infrared (NIR) fluorescence after reaction with NAD(P)H. By using KC8, it was demonstrated for the first time that the level of NAD(P)H in the mitochondria of living colorectal cancer (CRC) cells was highly related to the abnormality of the p53. Furthermore, KC8 was successfully used to differentiate not only between tumor and normal tissue but also between tumors with p53 abnormality and normal tumors when administered intravenously. Finally, we evaluated tumor heterogeneity through two fluorescent channels after treating a tumor with 5-Fu. This study provides a new tool for real-time monitoring of the p53 abnormality of CRC cells.

Modular Synthesis of a Tridecasaccharide Motif of Bacteroides vulgatus Lipopolysaccharides against Inflammatory Bowel Diseases through an Orthogonal One-Pot Glycosylation Strategy.

Lipopolysaccharides from Bacteroides vulgatus represent interesting targets for the treatment of inflammatory bowel diseases. However, efficient access to long, branched and complex lipopolysaccharides remains challenging. Herein, we report the modular synthesis of a tridecasaccharide from Bacteroides vulgates through an orthogonal one-pot glycosylation strategy based on glycosyl ortho-(1-phenylvinyl)benzoates, which avoids the issues of thioglycoside-based one-pot synthesis. Our approach also features: 1) 5,7-O-di-tert-butylsilylene-directed glycosylation for stereoselective construction of the α-Kdo linkage; 2) hydrogen-bond-mediated aglycone delivery for the stereoselective formation of ß-mannosidic bonds; 3) remote anchimeric assistance for stereoselective assembly of the α-fucosyl linkage; 4) several orthogonal one-pot synthetic steps and strategic use of orthogonal protecting groups to streamline oligosaccharide assembly; 5) convergent [1+6+6] one-pot synthesis of the target.

Eclampsia with hypothyroidism complicated with posterior reversible encephalopathy syndrome-a case report.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a rare neurological disorder with complex physiopathological mechanisms that have not been fully understood. Early identification is of great prognostic significance, of which the symptoms and radiological abnormalities can be completely reversed. If the diagnosis and treatment are delayed, ischemia and massive infarction may be developed in some patients. Posterior reversible encephalopathy syndrome (PRES) has been reported mainly in association with postpartum eclampsia, which have been rarely reported, while the association with hypothyroidism has not been reported at home or abroad. CASE PRESENTATION: Here we report on a pregnant 29-year-old with multipara and a chief complication of hypothyroidism. She presented in the emergency department with frequent attacks of severe headache symptoms resulting from reversible cerebral vasoconstriction syndrome (RCVS), accompanied with prenatal eclampsia. PRES was determined by radiological examination. CONCLUSION: To the best of our knowledge, this is the first case of PRES complicated by hypothyroidism and prepartum eclampsia.Clinicians should be alert for the co-occurence of eclampsia, PRES, and RCVS when patients have convulsions after a typical throbbing headache. Moreover, regular monitoring of thyroid function during pregnancy should also occupy certain special attention.

A Space-Dependent 'Enzyme-Substrate' Type Probe based on 'Carboxylesterase-Amide Group' for Ultrafast Fluorescent Imaging Orthotopic Hepatocellular Carcinoma.

Fast and selective fluorescence imaging for a biomarker to related-disease diagnosis remains a significant challenge due to complex physical environment. Human carboxylesterase (CE) is expected to be a potential biomarker of hepatocellular carcinoma (HCC) to improve the accuracy of diagnosis. However, existing probes for CE has slow response rate and low selectivity. Herein, the amide group is selected as CE-responsive sites based on the "substrate-hydrolysis enzymatic reaction" approach. From a series of off-on probes with leave groups in the amide unit, probe JFast is screened with the optimal combination of rapid response rate and high selectivity toward CE. JFast requires only 150 s to reach the maximum fluorescence at 676 nm in the presence of CE and free from the interference of other esterase. Computational docking simulations indicate the shortest distance between the CE and active site of JFast . Cell and in vivo imaging present that the probe can turn on the liver cancer cells and tumor region precisely. Importantly, JFast is allowed to specifically image orthotopic liver tumor rather than metastatic tumor and distinguish human primary liver cancer tissue from adjacent ones. This study provides a new tool for CE detection and promotes advancements in accurate HCC diagnosis.

Fast-Specific Fluorescent Probes to Visualize Norepinephrine Signaling Pathways and Its Flux in the Epileptic Mice Brain.

Norepinephrine (NE) is synthesized in the locus coeruleus and widely projected throughout the brain and spinal cord. It regulates various actions and consciousness linked to a variety of neurological diseases. A "hunting-shooting" strategy was proposed in this work to improve the specificity and response rate of an NE fluorescent probe: 2-(cyclohex-2-en-1-ylidene)malononitrile derivatives were chosen as a fluorophore. To create a dual-site probe, an aldehyde group was added to the ortho of the ester group (or benzene sulfonate). Because of its excellent electrophilic activity, the aldehyde group could rapidly "hunt" the amino group and then form an intramolecular five-membered ring via the nucleophilic reaction with the ß-hydroxyl group. The -NH- in the five-membered ring "shoots" the adjacent ester group, releasing the fluorophore and allowing for rapid and specific NE detection. The NE release and reuptake ″emetic″-″swallow″ transient process is captured and visualized under the action of the primary NE receptor drug. Furthermore, by introducing halogen into the fluorophore to lengthen the absorption wavelength, improve lipid solubility, and adjust the pKa appropriately, the probe successfully penetrated the blood-brain barrier (BBB). In situ synchronous probe imaging was used to detect the NE level in the brains of epileptic and normal mice, and abnormal expression of NE in the brain was discovered during epilepsy. Brain anatomy was used to examine the distribution and level changes of NE in various brain regions before and after epilepsy. This research provides useful tools and a theoretical foundation for diagnosing and treating central nervous system diseases early.

Enlarging the Stokes Shift by Weakening the π-Conjugation of Cyanines for High Signal-to-Noise Ratiometric Imaging.

The signal-to-noise ratio (SNR) is one of the key features of a fluorescent probe and one that often defines its potential utility for in vivo labeling and analyte detection applications. Here, it is reported that introducing a pyridine group into traditional cyanine-7 dyes in an asymmetric manner provides a series of tunable NIR fluorescent dyes (Cy-Mu-7) characterized by enhanced Stokes shifts (≈230 nm) compared to the parent cyanine 7 dye (<25 nm). The observed Stokes shift increase is ascribed to symmetry breaking of the Cy-Mu-7 core and a reduction in the extent of conjugation. The fluorescence signals of the Cy-Mu-7 dyes are enhanced upon confinement within the hydrophobic cavity of albumin or via spontaneous encapsulation within micelles in aqueous media. Utilizing the Cy-Mu-7, ultra-fast in vivo kidney labeling in mice is realized, and it is found that the liver injury will aggravate the burden of kidney by monitoring the fluorescence intensity ratio of kidney to liver. In addition, Cy-Mu-7 could be used as efficient chemiluminescence resonance energy transfer acceptor for the reaction between H2 O2 and bisoxalate. The potential utility of Cy-Mu-7 is illustrated via direct monitoring fluctuations in endogenous H2 O2 levels in a mouse model to mimic emergency room trauma.

An ultra-fast UV-electrochemical sensor based on Cu-MOF for highly sensitive and selective detection of ferric ions.

A 2D Cu-MOF: {[CuL(H2O)]}n (Cu-1, H2L = 3,4-ethylene dioxythiophene-2,5-dicarboxylic acid) was synthesized using the hydrothermal method. Cu-1 showed excellent solvent stability and was used to fabricate a UV ferric ion sensor. An ultra-low limit of detection (LOD) at 14.5 fM was obtained. Furthermore, N,N-dimethylformamide (DMF) as a 'turn-off' switch was introduced into the Cu-1 framework to construct another 2D Cu-MOF: {[CuL(DMF)]}n (Cu-2) by a single crystal to single crystal (SCSC) transformation method. Cu-2 lost the ability to recognize ferric ions and the switching effect of Fe3+ recognition was realized. Cyclic voltammograms (CVs) were employed to investigate this conversion process and provided a way for explaining the interaction mechanism between Cu-1 and ferric ions. We present an approach for designing and synthesizing MOFs that are suitable for ion sensing.

Comparison of hospitalization cause and risk factors between patients undergoing hemodialysis and peritoneal dialysis.

This retrospective study was designed to compare the cause of hospitalization and influencing factors between patients undergoing hemodialysis (HD) and peritoneal dialysis (PD). Baseline data and laboratory parameters of 192 dialysis patients (92 HD patients and 100 PD patients) were compared. Quantitative parameters with normal distribution were assessed using independent t-test or analysis of variance (ANOVA). Quantitative parameters with non-normal distribution were assessed by non-parametric test. Qualitative data were statistically compared using χ2 test. The number of patients with urban employee medical insurance (88 HD patients and 60 PD patients) and rural cooperative medical care (12 HD patients and 40 PD patients) significantly differed (P < .01). The hospitalization rate of PD patients was significantly higher than that of HD counterparts. The average length of hospital stay of PD patients was 10 days, remarkably longer than 8 days of HD patients (P < .01). The primary cause of hospitalization for HD patients was infection-related complications, followed by cardiovascular, cerebrovascular complications and dialysis access disorders. The primary cause of hospitalization for PD patients was infection-related complications, followed by dialysis access disorders, cardiovascular, and gastrointestinal complications. Compared with the HD group, the levels of hemoglobin, serum albumin, alkaline phosphatase, intact parathyroid hormone were significantly decreased, whereas serum urea nitrogen, serum creatinine, phosphorus levels and cardiothoracic ratio were remarkably increased in the PD group (all P < .01). The hospitalization rate of PD patients is relatively higher, and the length of hospital stay is longer. Extensive attention and efforts should be delivered to enhance the understanding of disease and lower the risk of complications for patients.

Sulfur and nitrogen served as electron donors to rescue short wave emission or fluorescence quenching caused by nucleophilic addition.

SO2 is not only a new potential gas signaling molecule, but also an antioxidant and antioxidant metabolite, which plays an important role in biophysiological and pathological processes. However, excessive intake of it can lead to serious complications of various diseases. Indole-iodide conjugated double bonds are often used as a sensitive response site for SO2, but the fluorescence of the system is often quenched after the nucleophilic addition of SO2. In this work, we introduced sulfur and nitrogen electron donors into a fluorophore, which rescued the trend of fluorescence quenching and enabled the system to develop a ratiometric fluorescence response for more accurate detection of SO32-. In addition, this probe can target mitochondria. The probe has good selectivity, sensitivity, a fast response (200 s) and a limit of detection (LOD) of 0.17 µM. Furthermore, the probe was successfully applied to visualize both endogenous and exogenous SO32- in Hela cells and zebrafish.