Binding Reaction Sites to Polysiloxanes: Unique Fluorescent Probe for

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Binding Reaction Sites to Polysiloxanes: Unique Fluorescent Probe for Reversible Detection of ClO-/GSH Pair and The in situ Imaging in Live Cells and Zebrafishes Yujing Zuo, Yu Zhang, Baoli Dong, Zhiming Gou, Tingxin Yang, and Weiying Lin Anal. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.analchem.8b05465 • Publication Date (Web): 15 Jan 2019 Downloaded from http://pubs.acs.org on January 15, 2019

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Analytical Chemistry

Binding Reaction Sites to Polysiloxanes: Unique Fluorescent Probe for Reversible Detection of ClO-/GSH Pair and The in situ Imaging in Live Cells and Zebrafishes Yujing Zuo, Yu Zhang, Baoli Dong, Zhiming Gou, Tingxin Yang, and Weiying Lin* Institute of Fluorescent Probes for Biological Imaging, School of Materials Science and Engineering, School of Chemistry and Chemical Engineering, University of Jinan, Shandong 250022, P.R. China E-mail: [email protected]. ABSTRACT: PDMS is biocompatible, economically viable, transparent, and facile to handle, and thus is suitable for the fluorescent microscopy and biological research. However, there has been no report about polysiloxane-based fluorescent probes that applied in bioimaging. In this report, a two-photon polysiloxane-based reversible luminescent probe (P1) was fabricated for the first time. P1 is a powerful tool for detecting the ClO-/GSH cycle in situ both in lived cells and in zebrafishs. This work demonstrated that the potential of polysiloxane based fluorescent probes for versatile in vivo or in vitro applications in future.

Cancer has been associated with cellular oxidation and reactive oxygen species (ROS)1-3. As one of the most important ROS, endogenous ClO- play a crucial role in circulatory system, while some diseases such as rheumatoid arthritis, cardiovascular diseases and even cancers will emerge at abnormal concentration level4-6. Glutathione (GSH), which located in live cells, play a significant role in holding the dynamic redox environment of cells and to repair or prevent oxidative damage leading to cell death or dysfunction. It is known that endogenous GSH was found to protect cells from the damage that caused by ClO- 7-11. However, although fluorescent probe rendered proper tools for the further exploration of ROS biology and have achieved great successes, distinguishing the complicated relationship between ClO- oxidation and GSH reduction remains an enormous challenge owing to the difficulty of sensing the ClO-/GSH cycle simultaneously. Therefore, the development of probes for detecting ClO-/GSH cycle is of great significance, for the bioimaging field would benefit immensely from the development of platforms for visualizing or monitoring the redox cycle between ClO- and GSH. As an ideal method, fluorescent probes have been widely used to detect the biological ClO-/GSH cycle. Therefore, several researches have been focused on the studies of the reversible process between ClO- and reductant12. Although successes have been achieved, there is still a need to fabricate novel ClO- probes with high selectivity and high sensitivity for the detection of endogenous ClO- in living biological environments. Polymers are promising for application in sensing and imaging applications. We anticipated that the novel strategy of binding locus onto polymer main chain could

increase the local concentration in the biological environment. Some conjugated polymers-based probes have been reported13; however, ClO- sensing applications have not been reported yet. As a special kind of polymers, polysiloxanes (PDMS) showed a broad transparency in the visible range, mechanical flexibility, and thermal and chemical stabilities14-17. However, due to their intrinsic properties18, polysiloxane based materials are poorly employed as photonic materials. Herein, we aimed to develop a novel kind of two-photon reversible polysiloxane-based fluorescence probe using the “grafting to” strategy for the detecting the redox process between ClO- oxidation and GSH recovery both in living cells and zebrafishs. This work demonstrated the first example of polymer-based reversible fluorescent probe. The optical properties of 1,8-naphthalimide derivatives are liable to be tuned by intramolecular charge transfer (ICT), which is one of the most frequently used mechanisms for designing fluorescent sensor19. As two-photon absorption (TPA) is more favorable than one-photon (OP) fluorescence for imaging applications in living systems, we selected the 1,8-naphthalimideas the two photon platform, in which an ClO-/GSH reversible site was then incorporated at the -4 position. The aminopropyl functionalized polysiloxane (P0) was selected as the polymer basement which inherited the superior properties of polysiloxane itself. Due to its abundant NH2 group in the side chain, P0 has the tendency to react with anhydride group in naphthalic anhydride. Herein, by combining the advantages of the ClO–

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reversible responsive fluorescent probes and the superior physical properties of polysiloxane, we rational designed and synthesized the first polysiloxane-based reversible fluorescent ClO-/GSH probe (P1) (Scheme 1). Compared with the previous report about polymer-based probe20, P1 exhibited many advantages (Table S1). The previous report illustrated a colormetric probe, which could not be used for bioimaging. Fortunately, as a fluorescent probe, P1 could be used for bioimaging due to the unique properties of fluorescent probes. Moreover, P1 was based on PDMS, which was biocompatible, economically viable, transparent, and facile to handle, and thus is suitable for the fluorescent microscopy and biological research. Our work demonstrated that the potential of polysiloxane based fluorescent probes for versatile in vivo or in vitro applications.

solutions. Those cations or salts induced negligible signal change, which indicated that P1 had good selectivity to ClO- [Figure S2]. After GSH added, and the fluorescence intensity increased gradually along with the adding of GSH. The results indicated that P1 showed excellent selectivity towards GSH in the presence of enzymes. The reaction of P1 with NaClO (5 equiv) almost finished within 200 s with t1/2 about 40 s [Figure S3], which made clear that P1 was a relative fast-response probe for the ClO- detection. The fast response of P1 to ClO- brought us the possibility to detecting ClOeffectively in situ within biotic conditions. P1 was a potential platform for development of reversible fluorescent probes; thus, we decided to further evaluate its photostability. Treatment of P1 with ceaseless irradiation of 405 nm for 8 h and induced no marked changes in the fluorescence intensity [Figure S4]. The result indicated that P1 exhibited good photostability. Furthermore, we confirmed the pH independence of its fluorescence for P1 [Figure S5]; thus, a conclusion could be drawn that P1 could sensitively and selectively detect ClO- in real time.

Scheme 1. Design and synthesis of P1, and the illustration of the oxidation reduction cycle between P1 and P1-ox. The specific synthesis route has been provided in Scheme 1. The structure of the target functionalized polysiloxane P1 was sufficiently characterized by 1HNMR, 13C-NMR analysis and GPC analysis. Moreover, the molecular weight (Mn) of P1 was about 4500 g/mol, which was higher than that of P0 (2700 g/mol), and the PDI was about 1.24 (Table S3). The increase of the molecular weight after functionalization also showed the success of the functionalization reaction. The grafting density was 10.3 % and was calculated by the integration of the 1H-NMR peaks[Figure S1]. With probe P1 in hand, we first investigated the UV absorption spectral of P1. After NaClO added (5 equiv), the absorption peak at 410 nm decreased, instead, a new peak at 350 nm emerged [Figure 1(a)]. The UV absorption change indicated the occurrence of oxidation reaction of P1. To investigate the specific selectivity of P1 towards NaClO, we evaluated the influence of other oxidants, such as Fe3+, Cu2+, H2O2, ONOO- and OH- (5 equiv). The fluorescence intensity changes of the P1 with various oxidants within 60 min were shown in Figure 1(b). The results showed that almost no changes in the fluorescence intensity upon the addition of the other oxidants, whereas ClO- could quench the fluorescence. To further study the sensibility of P1 extended to various ions, we added different cations (Cd2+, Al3+, Ag+, Ni2+, Ca2+, Co2+, Mg2+, and Sn2+) and sodium salts (SO42-, SCN, S2O32-, S2-, PO43-, OH-, NO3-, HSO3-, HCO3-) into the P1

Figure 1. (a). UV spectral of P1 and P1 treated with NaClO (4 equiv), (b) fluorescence intensity response of P1 (10 μM) to different species in aqueous solution (25 mM PBS buffer, pH=7.4, containing 10 % ethanol). Excited by 405 nm, (c). fluorescence spectra of P1 (10 μM) with NaClO (0–5 equiv) in aqueous solution (25 mM PBS buffer, pH=7.4, containing 10 % ethanol). Excited by 405 nm, (d) the linear relationship between the fluorescence quenching and the concentration of NaClO, insert: the digital photographs of P1 treated with NaClO with concentrations varied. Moreover, the fluorescence intensity decreased gradually upon ClO- added [Figure 1(c)]. The fluorescence intensity was linearly proportional (R = 0.9930) to the NaClO concentration in the range of 0–4 equiv. [Figure 1(d)]. According to the IUPAC recommendations, the detection limit was calculated with the formula: LOD = 3σ/k, where σ was the standard deviation for the fluorescence intensity of the solution and k represented the slope of the equation. The calculated detection limit of P1 was about 0.92 μ Μ. P1 exhibited higher LOD compared with those ClO- probe4, 5. The


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fluorescence changes of P1 toward NaClO suggested that the sulfur group of the probe was oxidized by ClO- and then formed sulfoxide which prevented the ICT effect from the sulfur atom to the carbanyl group with the naphthalimides. The mechanism for the ClO- detection is different from that in the previous report. Peng et. al. ultilized an imidazole oxidation reaction, which gives lower background fluorescence and higher signal-to-noise ratio. Guo et. al. proposed a N-chlorination hydrolysis mechanism for ClO-. P1 proceeded a sulfur oxidation reaction. Due to the difference of the mechanism, P1 could not achieve the same level of sensitivity and the kinetics as reported small molecule probes. The fluorescence changes of P1 toward NaClO suggested that the sulfur group of the probe was oxidized by ClO- and then formed sulfoxide which prevented the ICT effect from the sulfur atom to the carbanyl group with the naphthalimides. To confirm the principle clearly, a model reaction was designed (Scheme S1). N1 has been oxidized to N1-O by excess NaClO. As shown in the inserted photo of N1 and N1-O, the color change from light yellow N1 to color-less N1-O could be easily observed by naked eyes. 1H-NMR analysis showed that (Figure S6), after oxidation, the chemical shift of the proton in O=S-CH3 shifted to the low field due to the “deshielding effect”. The shift illustrated the success of the oxidation. The product was then subjected to ESI-MS analysis (Figure S7). According to the classic report, N1 exhibit a MS peak at m/z=243, corresponding to [N1]+ (calc. for [N1]+ m/z = 243.0223). After incubation of N1 with NaClO, a new peak at m/z = 260.8156 was found, which can be assigned to product [N1-O]+ generated from the oxidation of sulfur by ClO(calc. for [N1-O]+, m/z = 260.8150). Thus, the experiment confirmed the proposed reaction mechanism outlined in Scheme 1. (b)500

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Analytical Chemistry

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Fluorescence intensity was recorded at 495 nm, (d) reversibility cycles of P1 (10 μM) with NaClO and GSH. The oxidative stress induced by ClO- can be counterbalanced by GSH due to its ability to scavenge ROS in vivo, the reversibility of P1 towards GSH was then investigated via reversible reaction of the probe reaction between NaClO and GSH. P1 was firstly oxidized by 4 equiv. of NaClO and then treated with GSH. As shown in Figure 2(a), the fluorescence of P1 vanished in the presence of ClO-, and the fluorescence intensity increased gradually along with the adding of GSH. The fluorescence intensity with the same equivalent as that of NaClO. These experimental results revealed that P1 is capable of monitoring NaClO reversibly in the presence of GSH. The selectivity of P1 to the reductants was tested within 60 min [Figures 2(b)]. The results suggested that GSH could quickly return the luminescence intensity to the original level compared with the other reductants. The selectivity of P1 in the presence of enzymes have been measured. HeLa cell lysate has been used as a mixture of enzyme pool. P1 was firstly oxidized by 4 equiv. of ClO- and then treated with HeLa cell lysate (containing about 10,000 HeLa cells). As shown in Figure S8 (a) and (b), the fluorescence of P1 vanished in the presence of ClO-. However, after HeLa cell lysate treated for 60 min, the fluorescent intensity could recover about 10.8 %. The recovery may be attributed to the existence of GSH in HeLa cells. When the solution was treated again with NaClO, the fluorescence of the probe recovered to the starting point again and the reversible cycles can be repeated five more times [Figure 2(d)]. The P1 signal before and after treated with ClO-, GSH has been tested by UV spectra. As shown in Figure S9, after NaClO added, the absorption peak at 410 nm decreased, instead, a peak at 350 nm emerged. The However, after GSH added (5 equiv), the peak at 410 nm re-generated with the diminishing of the peak at 350 nm. UV absorption change showed the occurrence of oxidation and the reduction reaction of P1. Polysiloxane based materials is famous for their biocompatibility. To further extend the applications of P1 to bioimaging field, the cytotoxicity of P1 towards HeLa cells was then discussed [Figure S10]. Live HeLa cells were incubated with various concentrations ranged from 0 to 30 μM of P1 for 24 h, and then the cell viability was determined by the standard MTT method. The results indicated that the cell viability was 91 % at 30 μM. The cytotoxicity of P1 exhibited negligible cytotoxicity to cells.

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Figure 2. (a) Fluorescence spectra increasing of NaClO treated P1 (10 μM) toward GSH with various concentrations (25 mM PBS buffer, pH=7.4, containing 10 % ethanol), (b) fluorescence intensity response of NaClO treated P1 (10 μM) towards various kind of thiols in aqueous solution (25 mM PBS buffer, pH=7.4, containing 10 % ethanol). Excited by 405 nm, (c) Process of the fluorescence enhancement of probe P1 (10 μM) in the presence of 5 equiv. ClO- and 5 equiv. GSH.



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conditions. We speculated that the novel “grafting to” method enhanced the sensitivity of the probe in cells, for the “grafting to” method could magnify the local concentration of the probes from the molecular level. Merged

Green channel

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Figure 4. Imaging of endogenous OCl- in RAW 264.7 cells stained with the probe P1. (a) Merged image of RAW 264.7 macrophages cells stained with P1; (b) from the green channel; (c) brightfield image; Imaging of endogenous OCl- in RAW 264.7 cells stained with PMA and LPS stained with P1. (d) Merged image of RAW 264.7 macrophages cells stained with P1; (e) from the green channel; (f) brightfield image.

Figure 3. (a) Fluorescent images of HeLa cells stained with 30 μM of P1 and NaClO with different incubation times. Incubation time from 0 to 76 s. Shooting using the time-lapse movie mode with an interval of 4 s. λex = 405 nm; bar = 20 μm, (b) relative fluorescence intensity changes of the photos of cells in the green channel as a function of the time series. We further examined whether P1 functions in living cells. The utility of probe P1 for fluorescence imaging in living cells was investigated (Figure S11). Staining of HeLa cells with only P1 for 20 min provided significant fluorescence in green channel. To investigate the kinetics of oxidation of P1 in lived cells, fluorescent images of HeLa were obtained with different treating times of NaClO. After the incubation with P1 for 20 min, HeLa cells showed strong green emission. With the NaClO (30 uM) added, the green emission gradually decreased and difficult to observe within 40 s [Figure 3(a)]. Notably, due to endogenous GSH existed in cancer cells, the fluorescence renewed within 40 s. Furthermore, relative fluorescence intensity of these graphs was selected as a parameter to quantize the fluorescence change [Figure 3(b)]. The change in fluorescence intensity was consistent with the color change observed by the naked eye. The result in lived cells was consistent with the optical property tested in solutions. The viability of the reversible redox reaction within the HeLa cells was confirmed via the experiment. P1 showed excellent sensitivity in biotic

The detection of endogenous ClO- of P1 was tested in the murine live macrophage cell line RAW 264.7. At first, RAW 264.7 cells were incubated with P1 for 30 min and then washed by PBS buffer to remove the free P1. The RAW 264.7 cells stained with P1 showed strong fluorescence in the green channel with excitation at 405 nm (Figure 4). In contrast, a significant decrease in the green channel was observed in the RAW264.7 macrophage cells stimulated by both phorbol myristate acetate (PMA) and lipopolysaccharides (LPS). The decrease of the fluorescence signal is mainly due to the reaction between P1 and endogenous ClO-. The results showed that P1 is capable of fluorescence imaging of endogenously produced ClO- in RAW 264.7 macrophage cells. According to the cell images obtained under confocal microscope, the distribution and the morphology of the intracellular signals were not consisted with any organelles including mitochondria, lysosome, ER, Golgi aparatus, and nucleus. Considering that the probe P1 contained no organelle-targeting groups, the polymers should not accumulate in subcellular structures. P1 should be distributed in the cytoplasma. To further analyze the subcellular distribution of P1, HeLa cells were costained with probes that specific to various organelles, such as ER, mitochondria, and lysosomes. P1 showed a cytoplasm distribution [Figure S12]. The colocation coefficient between P1 and MitoTracker Red was 0.54, the result was 0.70 between P1 and lysosomes, while the data was 0.59 between P1 and ER. The results indicated that P1 did not colocalize with any of the organelle specific markers within the cytoplasm.


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Analytical Chemistry Corresponding Author * Weiying Lin

[email protected]

ACKNOWLEDGMENT This work was financially supported by NSFC (21472067, 21672083, 21877048), Natural Science Foundation of Shandong Province (ZR2018BB022), Taishan Scholar Foundation (TS201511041), and the startup fund of University of Jinan (309-10004, 1009428).

Supporting Information

Figure 5. (a) Fluorescent images and the corresponding in situ emission spectra of zebrafish stained with 30 μM of P1 and NaClO with different incubation times. Incubation time from 0 to 12 min. λex = 405 nm; bar = 20 μm, (b) relative fluorescence intensity changes of the photos of cells in the green channel as a function of the time series. P1 was used to detect the oxidation/reduction cycle in lived zebrafish under microscope. As shown in Figure 5(a), after treated with P1 for 30 min, the zebrafish exhibit intense fluorescence in green channel. Figure 5(b) illustrated the relative intensity of the color pictures in Figure 5(a). However, after treated with NaClO, the fluorescence vanished gradually within 5 min, and then recovered in 8 min. These bioimaging experimental results in HeLa and Raw 264.7 cells and in zebrafishs demonstrated that P1 was an efficient probe for detecting ClO-/GSH cycle in bioconditions in situ. The application of P1 in the reversible bioimaging field demonstrated that P1 has potential application in distinguishing the complicated relationship between ClO- oxidation and GSH reduction in the future. Polysiloxane-based materials possess two-photon absorption properties. Together with efficient intramolecular charge transfer (ICT) of 1,8-naphthalimide, which encouraged us to evaluate two-photon excitation properties of P1 in vivo. Loaded with P1, HeLa cells were analyzed by a two-photon fluorescent microscope (Figure S13). Similar to single-photon images (Figure 3), we observed intracellular localization of P1. Besides, after NaClO added, the fluorescence intensity decreased gradually as time went on within 30 s. In summary, we have rational designed and fabricated a novel polysiloxane-based reversible fluorescence probe P1. P1 could selectively detect NaClO/GSH redox cycle both in the solution and in bioconditions. As a unique polysiloxane-based probe, P1 shows two-photon luminescence, which is the first example of polysiloxane-based probe that exhibit twophoton luminescence. Confocal microscopy imaging in HeLa cell lines and in zebrafishes showed that the probe has excellent living cell permeability, which can monitor intracellular ClO-/GSH redox cycle continuously. We expect that the design strategy described herein could be extended to construct more polymer-based fluorescent probes showing enhanced sensitivity.

AUTHOR INFORMATION

The Supporting Information is available free of charge on the ACS Publications website. Experimental, 1H-NMR of P1, and the absorption or the emission spectra of the P1 treated with ClO-/GSH, photostability, cell viability, et. al.

REFERENCES 1. Iic, C.; Tuveson, D. A., ROS in Cancer: The Burning Question. Trends. Mol. Med. 2017, 23 (5), 411-429. 2. Prasad, S.; Gupta, S. C.; Tyagi, A. K., Reactive oxygen species (ROS) and cancer: Role of antioxidative nutraceuticals. Cancer. Lett. 2017, 387 (16), 95-105. 3. Brenneisen, P.; Reichert, A. S., Nanotherapy and Reactive Oxygen Species (ROS) in Cancer: A Novel Perspective. Antioxidants 2018, 7 (2), 31-39. 4. 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. Soci. 2014, 136 (37), 12820-12823. 5. Zhang, H.; Liu, J.; Liu, C.; Yu, P.; Sun, M.; Yan, X.; Guo, J. P.; Guo, W., Imaging lysosomal highly reactive oxygen species and lighting up cancer cells and tumors enabled by a Sirhodamine-based near-infrared fluorescent probe. Biomaterials 2017, 133, 60-69. 6. Yang, Y.; Qiu, F.; Wang, Y.; Feng, Y.; Song, X.; Tang, X.; Zhang, G.; Liu, W., A sensitive and selective off-on fluorescent probe for HClO in 100% aqueous solution and its applications in bioimaging. Sensor. Actuat. B-Chem. 2018, 260, 832-840. 7. Prütz, W, Interactions of Hypochlorous Acid with Pyrimidine Nucleotides, and Secondary Reactions of Chlorinated Pyrimidines with GSH, NADH, and Other Substrates. Arch. Biochem. & Biophys., 1998, 349(1), 0-191. 8. Gao, X.; Li, X.; Li, L.; Zhou, J.; Ma, H., A simple fluorescent offon probe for the discrimination of cysteine from glutathione. Chem. Commun. 2015, 51 (45), 9388-9390. 9. Ahn, Y. H.; Junseok Lee, A.; Chang, Y. T., Combinatorial Rosamine Library and Application to in Vivo Glutathione Probe. J. Am. Chem. Soc. 2007, 129 (15), 4510-4511. 10. Wang, F.; Guo, Z.; Li, X.; Li, X.; Zhao, C., Development of a small molecule probe capable of discriminating cysteine, homocysteine, and glutathione with three distinct turn-on fluorescent outputs. Chem-Eur. J. 2015, 20 (36), 11471-11478. 11. Lim, S. Y.; Hong, K. H.; Kim, D. I.; Kwon, H.; Kim, H. J., Tunable heptamethine-azo dye conjugate as an NIR fluorescent probe for the selective detection of mitochondrial glutathione over cysteine and homocysteine. J. Am. Chem. Soc. 2014, 136 (19), 7018-7025. 12. Zhang, B.; Yang, X.; Zhang, R.; Liu, Y.; Ren, X.; Xian, M.; Ye,



Y.; Zhao, Y., Lysosomal-targeted two-photon fluorescent probe to sense hypochlorous acid in live cells. Anal. Chem. 2017, 89 (19), 10384-10390. 13. Ekmekci, Z.; Yilmaz, M. D.; Akkaya, E. U., A monostyrylboradiazaindacene (BODIPY) derivative as colorimetric and fluorescent probe for cyanide ions. Org. Lett. 2008, 10 (3), 461-464. 14. Fawcett, A. S.; Hughes, T. C.; Zepeda-Velazquez, L.; Brook, M. A., Phototunable Cross-Linked Polysiloxanes. Macromolecules 2015, 48 (18), 6499-6507. 15. Fawcett, A. S.; Brook, M. A., Thermoplastic Silicone Elastomers through Self-Association of Pendant Coumarin Groups. Macromolecules 2014, 47 (5), 1656-1663. 16. Chojnowski, J.; Cypryk, M., Synthesis of linear polysiloxanes. In Silicon-Containing Polymers, Springer: 2000, pp 3-41. 17. Zilberzwige-Tal, S.; Gazit, E., Go with the flow-microfluidics approaches for amyloids research. Chem-Asian. J. 2018, 13 (22), 3437-3447. 18. Dmitriev, R. I.; Borisov, S. M.; Düssmann, H.; Sun, S.; Müller, B. J.; Prehn, J.; Baklaushev, V. P.; Klimant, I.; Papkovsky, D. B., Versatile Conjugated Polymer Nanoparticles for HighResolution O2 Imaging in Cells and 3D Tissue Models. Acs. Nano. 2015, 9 (5), 5275-5288. 19. Xia, X.; Zeng, F.; Zhang, P.; Lyu, J.; Huang, Y.; Wu, S., An ICTbased ratiometric fluorescent probe for hydrazine detection and its application in living cells and in vivo. Sensor. Actuat. BChem. 2016, 227, 411-418. 20. Balamurugan, A.; Lee, H.-i., Aldoxime-Derived WaterSoluble Polymer for the Multiple Analyte Sensing: Consecutive and Selective Detection of Hg2+, Ag+, ClO–, and Cysteine in Aqueous Media. Macromolecules 2015, 48 (12), 3934-3940.


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