Recognition of HClO in Live Cells with Separate ... - ACS Publications

Article pubs.acs.org/IECR

Recognition of HClO in Live Cells with Separate Signals Using a Ratiometric Fluorescent Sensor with Fast Response Jiangli Fan,*,† Huiying Mu,† Hao Zhu,† Jianjun Du,† Na Jiang,† Jingyun Wang,‡ and Xiaojun Peng† †

State Key Laboratory of Fine Chemicals, and ‡School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116023, China

Downloaded by UNIV OF NEBRASKA-LINCOLN on September 3, 2015 | http://pubs.acs.org Publication Date (Web): September 1, 2015 | doi: 10.1021/acs.iecr.5b01904

S Supporting Information *

ABSTRACT: Hypochlorous acid (HClO), one of the reactive oxygen species (ROS), is a key microbicidal agent which is used for natural defense; however, it is also involved in several human diseases. Although several efforts have been made to develop HClO-selective fluorescent sensors, most of them display delayed response time and the ratiometric sensors are rare. In the current work, we used a 3-pyrrole BODIPY dye as a new ratiometric fluorescent sensor (BRClO) for HClO. BRClO exhibited a 177-fold fluorescence ratio (F505 nm/F585 nm) enhancement in the presence of HClO over other ROS with fast response time (completed within 1 s). Confocal fluorescence imaging with BRClO showed separated signals in the presence of exogenous HClO in live cells. In addition, BRClO could be easily prepared as HClO test strips to detect HClO in aqueous solution and natural tap water.

■

by measuring the ratio of fluorescence intensities at two different wavelengths.21 In this work, we introduce a pyrrole group to the BODIPY skeleton at the 3-position, forming a π-extended BODIPYbased ratiometric sensor for HClO (BRClO) with the absorption and emission maximum at 559 and 585 nm, respectively. When BRClO was oxidized to the corresponding oxynitride product (BORClO) by HClO, the aromaticity of pyrrole was destroyed and its π extension for BODIPY core was blocked, which resulted in the blue shift of emission wavelength with a 177-fold enhancement in the emission ratio (F505 nm/ F585 nm). The oxidation reaction is selective toward HClO over other ROS. Importantly, BRClO can respond to HClO in an extremely short time (1 s) which is superior to the most reported fluorescent HClO sensors. The properties of BRClO enable its use in detecting HClO changes in the presence of exogenous HClO in live cells with clearly separated signals: BRClO stained the cytoplasm while BORClO was found to be prone to accumulate in the plasma membrane.

INTRODUCTION

Reactive oxygen species are emerging as critical signaling molecules1,2 and play a crucial role in various physiological and pathological processes. Among the various ROS, hypochlorous acid (HClO)/hypochlorite (ClO−), generated from H2O2 and Cl− by myeloperoxidase (MPO),3,4 is a potent antimicrobial agent for the immune system.5 However, as a result of the highly reactive and diffusible nature of HClO/ClO−,6 its uncontrolled production within phagocytes is involved in a variety of human diseases such as cardiovascular disease and inflammatory disease.7−10 Therefore, monitoring cellular HClO/ClO− concentration is significant for biological research, as well as clinical diagnoses. Fluorescence imaging technology, highlighted for its high spatial and temporal resolution, is regarded as a promising method for monitoring biological species in living cells.11−21 The designed strategies for HClO sensors are based on specific reactions between recognition groups and HClO that give highly fluorescent products.1,22−46 These HClO-reactive groups include p-methoxyphenol,33 dibenzoyl hydrazide,23 rhodaminehydroxamic acid,34 selenide,29 and so on. These specific reactions can efficiently differentiate HClO from other ROS. However, most of the reported HClO sensors display delayed response time,23−31 thus are not satisfactory for real-time monitoring of the fluctuation of HClO in its cellular site of action. In our previous work,42 2,4-dimethylpyrrole was found as a specific recognition site for HClO. It shows ultrasensitivity, fast response (within 1 s), and high selectivity toward HClO at the meso position of BODIPY fluorophore with an “enhanced PET” effect. However, many factors are known to influence the emission intensity, such as the illumination intensity and optical path length, which are prone to be disturbance in quantitative detection. A ratiometric approach can eliminate the effects of these factors to realize quantitative detection more effectively © XXXX American Chemical Society

■

RESULTS AND DISCUSSION BRClO was synthesized in a one-pot reaction according to the previously reported literature.47 Scheme 1 outlines the proposed synthetic mechanism of BRClO. First, we evaluated the spectroscopic properties of BRClO in aqueous media buffered to physiological pH (10 mM PBS, ethanol/water =1/ 9, v/v, pH 7.4). Free BRClO features one prominent absorption band centered at 559 nm (ε = 8.5 × 104 M−1 cm−1) and a corresponding emission maximum at 585 nm. Upon the addition of NaClO, the absorption intensity at 559 nm was decreased accompanied by the disappearance of the Received: May 22, 2015 Revised: July 25, 2015 Accepted: August 26, 2015

A

DOI: 10.1021/acs.iecr.5b01904 Ind. Eng. Chem. Res. XXXX, XXX, XXX−XXX

Article

Industrial & Engineering Chemistry Research


Scheme 1. Synthesis and Proposed Sensing Mechanism of BRClO

pink color of solution (Supporting Information, Figure S1). In the corresponding fluorescence spectrum, the emission of BRClO at 585 nm was gradually reduced and a new fluorescence band centered at 505 nm appeared which gradually enhanced in intensity with the increasing NaClO concentration. After 420 μM of NaClO was added, these changes were found to reach a plateau where a 22-fold fluorescence intensity (505 nm) and 177-fold ratio (F505 nm/ F585 nm) enhancement were obtained (Figure 1). In the

Figure 3. Fluorescence ratio (F505 nm/F585 nm) of BRClO (1 μM) change as a function of NaClO (0−100 μM) in PBS (0.01 M) solution (ethanol/water = 1/9, v/v, pH 7.4). λex = 480 nm.

Figure 4. Time courses of fluorescence ratio (F505 nm/F585 nm) of BRClO (1 μM) after adding 300 μM NaClO in PBS (0.01 M) solution (ethanol/water = 1/9, v/v, pH 7.4). Time range: 0−2.5 s. λex = 480 nm. Figure 1. Fluorescence spectra (a) and intensities at 505 and 585 nm (b) of BRClO (1 μM) upon the titration of NaClO (0−490 μM) in PBS (0.01 M) solution (ethanol/water = 1/9, v/v, pH 7.4). λex = 480 nm.

was conducted to investigate a suitable pH range for HClO sensing. Figure S6 showed that BRClO kept a constant minimal value at pH 4 to 9, after the addition of 400 μM NaClO, the emission intensity (505 nm) and ratio (F505 nm/F585 nm) became significantly higher. These results clearly explain that this sensor can be used in a broad pH range. To explore the sensing mechanism of BRClO, BRClO was treated with NaClO and the high resolving mass spectrum was recorded. As shown in Figure S7, one peak at m/z 287.0035 (calcd: 287.1039) appeared which could be assigned as [BORClO + H]+. On the other hand, the ratiometric fluorescence signal output of BRClO with HClO was clarified in terms of the frontier obital energy diagrams with the density functional theory (DFT) method [B3LYP/6-31G(d, p)] using the Gaussian 09 program (Figure 5). For both BRClO and

selectivity test, other ROS (H2O2, O2−, TBHP, HO·, TBO·, O2, NO·, ONOO−) did not lead to remarkable fluorescence variations of BRClO (Figure 2). To examine the sensitivity of 1

Figure 2. Fluorescence responses (F505 nm/F585 nm) of BRClO (1 μM) toward various ROS (100 μM) in PBS (0.01 M) solution (ethanol/ water =1/9, v/v, pH 7.4). λex = 480 nm.

BRClO to HOCl, titration of HOCl at low concentration was carried out. As shown in Figure 3 and Figure S2, the fluorescence ratios (F505 nm/F585 nm) and intensities (505 nm) of BRClO were linearly proportional (R2 = 0.99) to the HClO concentrations ranging from 0 to 100 μM with detection limits of 1.95 μM and 0.59 μM (3σ/k) for ratio measurement and intensity, respectively. The time-dependent (0−600 s) fluorescence ratio (F505 nm/F585 nm) and intensity (505 nm) changes of BRClO in the presence of NaClO (Figure 4 and Figures S3−S5) revealed the fast reaction kinetics (completed within 1s) and high stability of the oxidation product. Indeed, the short response time is essential for the real-time detection of HClO. In addition, a pH-dependence experiment of BRClO

Figure 5. HOMO−LUMO energy levels and interfacial plots of the orbitals for BRClO and BORClO with the calculated percentage of transition. Calculations were performed with the DFT method [B3LYP/6-31G(d, p)] using the Gaussian 09 program. B


Article


Finally, we applied BRClO in test strips. Filter papers (3 × 0.5 cm2) were immersed in an ethanol solution of BRClO (1 mM) and then dried in air to prepare test strips (Figure 7).

BORClO, highest occupied molecular orbital (HOMO) to lowest unoccupied molecular orbital (LUMO) transitions represented electron density redistributions from the 3-pyrrole group to the BODIPY core, indicating intramolecular charge transfer (ICT) processes between the two units. The energy gap between the HOMO and LUMO of BRClO (2.608 eV) was smaller than that of BORClO (2.727 eV), which agrees well with a blue shift in fluorescence observed upon treatment of BRClO with HClO. On the basis of the above results, the proposed reaction mechanism shown in Scheme 1 is strongly supported. With spectroscopic data establishing that BRClO can selectively respond to HClO, we then evaluated BRClO in live-cell imaging assays (Figure 6 and Figure S8). After


Figure 7. Color changes of test strips for detecting HClO in aqueous solution with different concentrations.

When exposed to the NaClO aqueous solution, the pink color of test strips vanished gradually with the increasing NaClO concentration (0.1, 1, 10, 100 μM). In addition, after immersed in tap water, the color of test strip became lighter, suggesting that BRClO can detect HClO in natural water of significantly complex composition. Unfortunately, the ratiometric fluorescence measurement of BRClO cannot work in test strips (data not shown).

■

CONCLUSIONS In summary, by introducing a pyrrole group into the 3-position of a Bodipy skeleton, we developed a HClO-specific smallmolecule fluorescent indicator that features a marked ratiometric (F505 nm/F585 nm) response, high selectivity for HClO over other ROS as well as pH independence. Importantly, the reaction of BRClO with HClO can be completed in an extremely short time (1 s) which is helpful for real-time monitoring the fluctuation of HClO in its cellular site of action. Through HRMS and computational calculation, the sensing mechanism of BRClO toward HClO was verified. The excellent sensing properties of BRClO and its biocompatibility permit imaging of intracellular HClO. It is noted that BRClO showed clearly separated signals after oxidation by HClO in live cells: red (BRClO) stayed in the cytoplasm and green (BORClO) was accumulated in the plasma membrane. Finally, BRClO was used in the form of test strips for qualitative detection of HClO in natural tap water. We believe that BRClO provides a promising chemical pool for the study of HClO science in the biological and environmental systems.

Figure 6. Confocal fluorescence imaging of without (top) and with (bottom) exogenous NaClO (100 μM) in MCF-7 cells using probe BRClO (1 μM) for 30 min at 37 °C. (a,d) green channel (490−520 nm); (b,e) red channel (560−600 nm); (c,f) overlay image of (a,b, d,e). λex = 488 nm. Scale bar = 30 μm.

incubation of MCF-7 cells with 1 μM BRClO for 30 min at 37 °C, BRClO penetrated through the cell membrane and stained the cytoplasm with clear fluorescence at the red emission channel of 560 nm-600 nm (Figure 6b). In contrast, there was no measurable signal in the green emission channel of 490 nm−520 nm (Figure 6a). By treating the cells with exogenous NaClO (100 μM), the fluorescence in the red channel (Figure 6e) stayed at the cytoplasm region with significantly decreasing intensity, but the green emission signal (Figure 6d) emerged obviously localized in the plasma membranes. As shown in Figure 6c,f, there was almost no overlap between the green and red images. This interesting phenomenon might occur because the lipophilic linear structure and charged oxynitride of BORClO contribute to its localization in the plasma membranes.48 This result indicates that BRClO is capable of detecting HClO changes in the presence of exogenous HClO in live cells with clearly “separate signals”: the background signal is in the cytoplasm; the target signal is in the plasma membrane. To evaluate cytotoxicity of sensor BRClO, we performed 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays in MCF-7 cells with 1, 5, 10, 50, and 500 μM sensor BRClO for 24 h, respectively. The result clearly showed that our proposed sensor was almost of no toxicity to cultured cells under the experimental conditions at the amount of 50 μM for 24 h (Figure S9).

■

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.iecr.5b01904. Synthesis, additional spectroscopic, time courses, MS spectra, pH titration, MTT results, confocal ratio image, 1 H NMR and 13C NMR spectra (PDF)

■

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. Notes

The authors declare no competing financial interest. C


Article


■

(18) Guo, Z.; Zhu, W.; Tian, H. Hydrophilic Copolymer Bearing Dicyanomethylene-4H-pyran Moiety As Fluorescent Film Sensor for Cu2+ and Pyrophosphate Anion. Macromolecules 2010, 43, 739−744. (19) Shen, L.; Lu, X.; Tian, H.; Zhu, W. A Long Wavelength Fluorescent Hydrophilic Copolymer Based on Naphthalenediimide as pH Sensor with Broad Linear Response Range. Macromolecules 2011, 44, 5612−5618. (20) Qu, Y.; Hua, J.; Tian, H. Colorimetric and Ratiometric Red Fluorescent Chemosensor for Fluoride Ion Based on Diketopyrrolopyrrole. Org. Lett. 2010, 12, 3320−3323. (21) Du, J.; Fan, J.; Peng, X.; Li, H.; Sun, S. The quinoline derivative of ratiometric and sensitive fluorescent zinc probe based on deprotonation. Sens. Actuators, B 2010, 144, 337−341. (22) Chen, X.; Tian, X.; Shin, I.; Yoon, J. Fluorescent and luminescent probes for detection of reactive oxygen and nitrogen species. Chem. Soc. Rev. 2011, 40, 4783−4804. (23) Chen, X.; Wang, X.; Wang, S.; Shi, W.; Wang, K.; Ma, H. A Highly Selective and Sensitive Fluorescence Probe for the Hypochlorite Anion. Chem. - Eur. J. 2008, 14, 4719−4724. (24) Panizzi, P.; Nahrendorf, M.; Wildgruber, M.; Waterman, P.; Figueiredo, J.-L.; Aikawa, E.; McCarthy, J.; Weissleder, R.; Hilderbrand, S. A. Oxazine Conjugated Nanoparticle Detects in Vivo Hypochlorous Acid and Peroxynitrite Generation. J. Am. Chem. Soc. 2009, 131, 15739−15744. (25) Yuan, L.; Lin, W.; Song, J.; Yang, Y. Development of an ICTbased ratiometric fluorescent hypochlorite probe suitable for living cell imaging. Chem. Commun. 2011, 47, 12691−12693. (26) Kim, T.-I.; Park, S.; Choi, Y.; Kim, Y. A BODIPY-Based Probe for the Selective Detection of Hypochlorous Acid in Living Cells. Chem. - Asian J. 2011, 6, 1358−1361. (27) Zhou, Y.; Li, J.-Y.; Chu, K.-H.; Liu, K.; Yao, C.; Li, J.-Y. Fluorescence turn-on detection of hypochlorous acid via HOClpromoted dihydrofluorescein-ether oxidation and its application in vivo. Chem. Commun. 2012, 48, 4677−4679. (28) Yuan, L.; Lin, W.; Xie, Y.; Chen, B.; Song, J. Fluorescent Detection of Hypochlorous Acid from Turn-On to FRET-Based Ratiometry by a HOCl-Mediated Cyclization Reaction. Chem. - Eur. J. 2012, 18, 2700−2706. (29) Lou, Z.; Li, P.; Pan, Q.; Han, K. A reversible fluorescent probe for detecting hypochloric acid in living cells and animals: utilizing a novel strategy for effectively modulating the fluorescence of selenide and selenoxide. Chem. Commun. 2013, 49, 2445−2447. (30) Lou, Z.; Li, P.; Song, P.; Han, K. Ratiometric fluorescence imaging of cellular hypochlorous acid based on heptamethine cyanine dyes. Analyst 2013, 138, 6291−6295. (31) Liu, F.; Wu, T.; Cao, J.; Zhang, H.; Hu, M.; Sun, S.; Song, F.; Fan, J.; Wang, J.; Peng, X. A novel fluorescent sensor for detection of highly reactive oxygen species, and for imaging such endogenous hROS in the mitochondria of living cells. Analyst 2013, 138, 775−778. (32) Shepherd, J.; Hilderbrand, S. A.; Waterman, P.; Heinecke, J. W.; Weissleder, R.; Libby, P. A Fluorescent Probe for the Detection of Myeloperoxidase Activity in Atherosclerosis-Associated Macrophages. Chem. Biol. 2007, 14, 1221−1231. (33) Sun, Z.-N.; Liu, F.-Q.; Chen, Y.; Tam, P. K. H.; Yang, D. A Highly Specific BODIPY-Based Fluorescent Probe for the Detection of Hypochlorous Acid. Org. Lett. 2008, 10, 2171−2174. (34) Yang, Y.-K.; Cho, H. J.; Lee, J.; Shin, I.; Tae, J. A Rhodamine− Hydroxamic Acid-Based Fluorescent Probe for Hypochlorous Acid and Its Applications to Biological Imagings. Org. Lett. 2009, 11, 859− 861. (35) Koide, Y.; Urano, Y.; Hanaoka, K.; Terai, T.; Nagano, T. Development of an Si-Rhodamine-Based Far-Red to Near-Infrared Fluorescence Probe Selective for Hypochlorous Acid and Its Applications for Biological Imaging. J. Am. Chem. Soc. 2011, 133, 5680−5682. (36) Chen, G.; Song, F.; Wang, J.; Yang, Z.; Sun, S.; Fan, J.; Qiang, X.; Wang, X.; Dou, B.; Peng, X. FRET spectral unmixing: a ratiometric fluorescent nanoprobe for hypochlorite. Chem. Commun. 2012, 48, 2949−2951.

ACKNOWLEDGMENTS This work was financially supported by NSF of China (21422601, 21136002, 21421005 and 21406028), National Basic Research Program of China (2013CB733702), Ministry of Education (NCET-12-0080), the General Project of Liaoning Province Department of Education (L2013024) and the Fundamental Research Funds for the Central Universities (DUT14ZD214).


■

REFERENCES

(1) Kenmoku, S.; Urano, Y.; Kojima, H.; Nagano, T. Development of a Highly Specific Rhodamine-Based Fluorescence Probe for Hypochlorous Acid and Its Application to Real-Time Imaging of Phagocytosis. J. Am. Chem. Soc. 2007, 129, 7313−7318. (2) Manke, A.; Luanpitpong, S.; Dong, C.; Wang, L.; He, X.; Battelli, L.; Derk, R.; Stueckle, T.; Porter, D.; Sager, T.; Gou, H.; Dinu, C.; Wu, N.; Mercer, R.; Rojanasakul, Y. Effect of Fiber Length on Carbon Nanotube-Induced Fibrogenesis. Int. J. Mol. Sci. 2014, 15, 7444−7461. (3) Harrison, J. E.; Schultz, J. Studies on the chlorinating activity of myeloperoxidase. J. Biol. Chem. 1976, 251, 1371−1374. (4) Winterbourn, C. C. Myeloperoxidase as an effective inhibitor of hydroxyl radical production. Implications for the oxidative reactions of neutrophils. J. Clin. Invest. 1986, 78, 545−550. (5) Lapenna, D.; Cuccurullo, F. Hypochlorous acid and its pharmacological antagonism: An update picture. Gen. Pharmacol. 1996, 27, 1145−1147. (6) Klebanoff, S. J. Myeloperoxidase: friend and foe. J. Leukocyte Biol. 2005, 77, 598−625. (7) Hammerschmidt, S.; Büchler, N.; Wahn, H. TIssue lipid peroxidation and reduced glutathione depletion in hypochloriteinduced lung injury*. Chest 2002, 121, 573−581. (8) Wu, S. M.; Pizzo, S. V. α2-Macroglobulin from Rheumatoid Arthritis Synovial Fluid: Functional Analysis Defines a Role for Oxidation in Inflammation. Arch. Biochem. Biophys. 2001, 391, 119− 126. (9) Hasegawa, T.; Malle, E.; Farhood, A.; Jaeschke, H. Generation of hypochlorite-modified proteins by neutrophils during ischemiareperfusion injury in rat liver: attenuation by ischemic preconditioning. Am. J. Physiol. Gastrointest. Liver. Physiol. 2005, 289, G760−767. (10) Sugiyama, S.; Okada, Y.; Sukhova, G. K.; Virmani, R.; Heinecke, J. W.; Libby, P. Macrophage Myeloperoxidase Regulation by Granulocyte Macrophage Colony-Stimulating Factor in Human Atherosclerosis and Implications in Acute Coronary Syndromes. Am. J. Pathol. 2001, 158, 879−891. (11) Du, J.; Hu, M.; Fan, J.; Peng, X. Fluorescent chemodosimeters using ″mild″ chemical events for the detection of small anions and cations in biological and environmental media. Chem. Soc. Rev. 2012, 41, 4511−4535. (12) Fan, J.; Hu, M.; Zhan, P.; Peng, X. Energy transfer cassettes based on organic fluorophores: construction and applications in ratiometric sensing. Chem. Soc. Rev. 2013, 42, 29−43. (13) Xu, Z.; Yoon, J.; Spring, D. R. Fluorescent chemosensors for Zn2+. Chem. Soc. Rev. 2010, 39, 1996−2006. (14) Zhu, H.; Fan, J.; Wang, B.; Peng, X. Fluorescent, MRI, and colorimetric chemical sensors for the first-row d-block metal ions. Chem. Soc. Rev. 2015, 44, 4337. (15) Wu, X.; Guo, Z.; Wu, Y.; Zhu, S.; James, T. D.; Zhu, W. NearInfrared Colorimetric and Fluorescent Cu2+ Sensors Based on Indoline−Benzothiadiazole Derivatives via Formation of Radical Cations. ACS Appl. Mater. Interfaces 2013, 5, 12215−12220. (16) Ding, Y.; Li, X.; Li, T.; Zhu, W.; Xie, Y. α-Monoacylated and α,α′- and α,β′-Diacylated Dipyrrins as Highly Sensitive Fluorescence ″Turn-on″ Zn2+ Probes. J. Org. Chem. 2013, 78, 5328−5338. (17) Chen, G.; Song, F.; Xiong, X.; Peng, X. Fluorescent Nanosensors Based on Fluorescence Resonance Energy Transfer (FRET). Ind. Eng. Chem. Res. 2013, 52, 11228−11245. D


Article


Industrial & Engineering Chemistry Research (37) Xu, Q.; Lee, K.-A.; Lee, S.; Lee, K. M.; Lee, W.-J.; Yoon, J. A Highly Specific Fluorescent Probe for Hypochlorous Acid and Its Application in Imaging Microbe-Induced HOCl Production. J. Am. Chem. Soc. 2013, 135, 9944−9949. (38) Cheng, G.; Fan, J.; Sun, W.; Sui, K.; Jin, X.; Wang, J.; Peng, X. A highly specific BODIPY-based probe localized in mitochondria for HClO imaging. Analyst 2013, 138, 6091−6096. (39) Wu, X.; Li, Z.; Yang, L.; Han, J.; Han, S. A self-referenced nanodosimeter for reaction based ratiometric imaging of hypochlorous acid in living cells. Chem. Sci. 2013, 4, 460−467. (40) Manjare, S. T.; Kim, J.; Lee, Y.; Churchill, D. G. Facile mesoBODIPY Annulation and Selective Sensing of Hypochlorite in Water. Org. Lett. 2013, 16, 520−523. (41) Liu, S.-R.; Wu, S.-P. Hypochlorous Acid Turn-on Fluorescent Probe Based on Oxidation of Diphenyl Selenide. Org. Lett. 2013, 15, 878−881. (42) Zhu, H.; Fan, J.; Wang, J.; Mu, H.; Peng, X. An “Enhanced PET”-Based Fluorescent Probe with Ultrasensitivity for Imaging Basal and Elesclomol-Induced HClO in Cancer Cells. J. Am. Chem. Soc. 2014, 136, 12820−12823. (43) Wang, X.; Wang, X.; Feng, Y.; Zhu, M.; Yin, H.; Guo, Q.; Meng, X. A two-photon fluorescent probe for detecting endogenous hypochlorite in living cells. Dalton Trans. 2015, 44, 6613−6619. (44) Li, J.; Huo, F.; Yin, C. A selective colorimetric and fluorescent probe for the detection of ClO− and its application in bioimaging. RSC Adv. 2014, 4, 44610−44613. (45) Ma, F.; Sun, M.; Zhang, K.; Zhang, Y.; Zhu, H.; Wu, L.; Huang, D.; Wang, S. An oxidative cleavage-based ratiometric fluorescent probe for hypochlorous acid detection and imaging. RSC Adv. 2014, 4, 59961−59964. (46) Sun, M.; Yu, H.; Zhu, H.; Ma, F.; Zhang, S.; Huang, D.; Wang, S. Oxidative Cleavage-Based Near-Infrared Fluorescent Probe for Hypochlorous Acid Detection and Myeloperoxidase Activity Evaluation. Anal. Chem. 2014, 86, 671−677. (47) Zhang, M.; Hao, E.; Xu, Y.; Zhang, S.; Zhu, H.; Wang, Q.; Yu, C.; Jiao, L. One-pot efficient synthesis of pyrrolyl BODIPY dyes from pyrrole and acyl chloride. RSC Adv. 2012, 2, 11215−11218. (48) Zhang, X.; Wang, C.; Jin, L.; Han, Z.; Xiao, Y. Photostable Bipolar Fluorescent Probe for Video Tracking Plasma Membranes Related Cellular Processes. ACS Appl. Mater. Interfaces 2014, 6, 12372−12379.

E


Recognition of HClO in Live Cells with Separate ... - ACS Publications

Recommend Documents