在本篇研究中，我們基於螢光半導體高分子奈米顆粒(semiconducting polymer dots, Pdots)有良好的光穩定性、寬廣的吸收波段、高能量傳遞與低生物毒性、易作表面修飾等優點來設計偵測探針。利用FRET (Förster resonance energy transfer)能量傳遞機制，結合以Heptamethine cyanine作為主體放射近紅外光染劑的螢光探針，利用螢光比例法對偵測物來定量，分別發展於檢測細胞中的酸鹼值以及對穀胱甘肽的定量。

(一) 發展以半導體高分子奈米顆粒結合Heptamethine cyanine 近紅外光染劑作為螢光探針，偵測細胞中的酸鹼值：
細胞內的酸鹼值對於細胞的新陳代謝有著很重要的關聯，一般來說幾乎所有蛋白質都是依據pH值去維持它們的結構以及功能性。除此之外pH值也在細胞增殖、細胞凋亡、抗藥性、吞噬作用、胞吞作用以及信號傳輸中扮演著非常重要的角色，此外，在肌肉或其他興奮性組織（例如腦以及神經）中的一種高能磷酸化合物，是高能磷酸基的暫時貯存形式。最近也被指出細胞胞漿的酸鹼值對磷酸肌酸的修復也很重要。因此細胞內的酸鹼值是非常嚴格的，細胞內的pH值只要有一點不正常就代表一些身體上的問題產生，例如像是癌症以及阿茲海默症等，偏差更大甚至可能致死。因此若能在活體內準確地了解、監控整個細胞內的酸鹼值關聯是非常重要的突破，然而傳統的pH定量方法如電化學法因為空間解析度差、NMR則因為操作困難而受到限制，因此我們必須發展更快速更便利的方式來進行偵測。其中藉由螢光偵測技術，具有高解析度、非破壞性、能夠設計各式各樣的螢光探針去達到高選擇性並且對細胞影響小，是目前應用在細胞研究中最有利的技術。
設計此螢光探針的最終目的是為了能夠做到生物應用，所以我們以Heptamethine cyanine作為染劑的選擇，結構中帶有電赫使其更容易進入細胞，利用本身結構帶有的長共軛鏈，修飾上具推電子能力的官能基piperazine，利用它在酸性環境下會受到質子化，降低推電子基能力並延伸共軛鏈使吸收紅移的現象。因此在本研究中我們利用Pdots易作表面修飾的特色，在高分子端設計出COOH官能基、以及在近紅外光染劑部分則是修飾出NH2官能基，將合成出來的高分子利用奈米再沉澱法製作成Pdots後，以水相修飾的方式將近紅外光染劑修飾上去，利用FRET能量傳遞機制，對偵測物酸鹼值以螢光比例法作分析定量。
關鍵字：螢光高分子奈米顆粒、近紅外光染劑、酸鹼螢光探針、螢光共振能量轉移、螢光訊號比例
(二) 發展一基於半導體高分子奈米顆粒結合Heptamethine cyanine 近紅外光染劑作為螢光探針，檢測穀胱甘肽的含量
GSH是細胞內最豐富的生物硫醇，濃度範圍在1~15 mmol /L。GSH會參與許多病理與生物學的過程，且在維持細胞內氧化還原態的平衡中扮演了重要角色。能夠保護細胞中的成分不被活性氧(ROS)損壞，並且不同濃度的GSH也與多種細胞功能有關，包括了生物的代謝、基因調控、細胞內訊號傳遞、壓力反應、免疫反應以及抵抗癌症放射治療與化療的能力。因此，在生物化學研究和相關的疾病中，是非常需要能夠知道細胞環境與體內中GSH濃度的方法。
高效液相色譜法（HPLC, high performance liquid chromatography）、毛細管電泳、氣相色譜質譜(GC-MS, Gas chromatography–mass spectrometry)和液相層析質譜儀(LC-MS, Liquid chromatography–mass spectrometry這些分析技術已被用於生物硫醇的檢測中。可是上述的方法是費時且須昂貴的儀器。相較之下，合適的探針結合螢光技術較占優勢，因其具有非破壞性與高敏感性，並且可以提供體內生物硫醇的定位與數量之訊息。大多是基於400-600的短至中段的放射波長，像是coumarin、BODIPY、rhodamine等等，而螢光探針在體內的成像所需的波長範圍在NIR (650-900nm) 較為合適以及近紅外光放射光能夠避免生物細胞自發螢光以達到更高訊雜比，且有成像較佳與對生物樣品損害小之優點。因此在本研究中，我們嘗試設計出一對GSH有偵測性的近紅外光探針，在Heptamethine cyanine 上修飾上azobenzene官能基，作為一個光誘導電子轉移(PET, photoinduced electron transfer)機制使染劑螢光產生消光現象，並結合Semiconducting Polymer Dots以達到訊號放大的效果，在含有GSH的環境下，會對官能基進行取代反應，將原本的azobenzene官能基切斷使染劑螢光恢復，達到定量、定位的偵測效果。

In this study, we used the advantages of good light stability, broad absorption band, high energy transfer and low biotoxicity, easy surface modification, based fluorescent semiconductor polymer nanoparticles (Pdots) to design the detection probe. Using the FRET (Förster resonance energy transfer) energy transfer mechanism, combined with Heptamethine cyanine as the radiation near infrared light sensor, developed to the ratiometric method to quantify pH values and quantification of glutathione.
(i) Heptamethine cyanine Based Semiconducting Polymer Dots for Detection of Cellular pH.
The intracellular pH is very important for cell metabolism, and almost all proteins are based on pH values to maintain their structure and functionality. In addition, pH also plays a very important role in cell proliferation, apoptosis, drug resistance, phagocytosis, endocytosis and signaling.
In addition, it has recently been shown that the cytosolic acidity of cells creatine repair is also important. So the intracellular pH is very strict, as long as there is a little abnormal on behalf of some physical problems, such as cancer and Alzheimer's disease, the greater the deviation may even cause death. Therefore, if we can accurately understand and monitoring the entire cell pH in vivo is a very important breakthrough. However, the traditional pH quantitative methods such as electrochemical method because of poor spatial resolution, NMR is limited because of operational difficulties, So we have to develop a faster and more convenient way to detect. Which by fluorescence detection technology, with high resolution, non-destructive, able to design to achieve high selectivity, is currently used in cell research.
The ultimate goal of this fluorescent probe is to be able to achieve biological applications, so we use Heptamethine cyanine as a choice of dye, the use of its own structure with a long conjugate chain, modified with a electron-donating functional group based piperazine . The use of it in the acidic environment will be protonated, reducing the ability to donate electrons and extend the conjugate chain to absorb redshift phenomenon. Therefore, in this study, we use the advantage of Pdots easy - to - make the surface modification characteristics, in the polymer side we design of COOH functional groups, and in the near-infrared dye part is modified with NH2 functional groups. The FRET energy transfer mechanism was used to calibrate the pH value of the detective substance.
Keywords : Semiconducting polymer dots、Near-infrared dyes、pH sensing、FRET、Fluorescence ratiometric analysis
( ii )Heptamethine cyanine Based Semiconducting Polymer Dots for cellular Quantification of Glutathione
GSH is the most abundant bio-mercaptan in cells, the concentration range of 1~15 mmol / L. GSH is involved in many pathology and biology processes and plays an important role in maintaining the balance of intracellular redox states. ROS(reactive oxygen species), and different concentrations of GSH are also associated with a variety of cellular functions, including biological metabolism, gene regulation, intracellular signaling, stress response, immune response, and resistance to cancer、radiation treatment and chemotherapy. Therefore, in biochemical research and related diseases, so there is a great need to be able to know the cellular environment and the GSH concentration in vivo.
High performance liquid chromatography (HPLC), capillary electrophoresis, gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LCMS, Liquid chromatography-mass spectrometry) Has been used in the detection of bio-mercaptan, but the above method is time-consuming and too expensive. In contrast, the appropriate probe combined with fluorescent technology is more dominant because of its non-destructive and high sensitivity, and can provide the location of the bio-mercaptan in the number and the location. Mostly based on 400nm-600nm of the radiation wavelength, such as coumarin, BODIPY, rhodamine, etc.. And fluorescent probe in vivo imaging wavelength range required in the NIR (650-900nm) is more appropriate and near infrared Light-emitting light can avoid spontaneous fluorescence of biological cells, in order to achieve a higher signal to noise ratio, and the advantages of small damage to biological samples. Therefore, in this study, we try to design a GSH detectable near-infrared light probe, modified on the Heptamethine cyanine with azobenzene functional group, as a light induced electron transfer (PET, photoinduced electron transfer) mechanism to dye quenching phenomenon. Using Semiconducting Polymer Dots to achieve the effect of signal amplification. In the presence of GSH environment, will replace the functional group, the original azobenzene cut off the dye and fluorescence recovery for quantitative analysis.

論文審定書 i
謝誌 ii
中文摘要 iii
Abstract vi
目錄 ix
圖目錄 xiii
表目錄 xvii
化學結構縮寫表 xviii
第一部分 緒論 1
第一章 前言 1
1-1 介紹螢光探針 2
1-2 Pdots歷史發展 3
1-3 Pdots製備方式 8
1-4 螢光共振能量轉移(FRET) 9
1-5 Pdots的應用 11
第二章 研究動機 19
第二部分 以半導體高分子奈米顆粒結合Heptamethine cyanine 近紅外光染劑作為螢光探針，偵測細胞中的酸鹼值 20
第一章 前言 20
第二章 實驗部分 21
2-1 實驗藥品 21
2-2 實驗儀器以及裝置 22
2-3 合成部分以及設計 25
2-4 Pdots水相修飾實驗 37
2-5 細胞毒性以及胞吞實驗 39
第三章 結果與討論 41
3-1 探討有機染劑在不同pH值下的光譜 41
3-2 有機染劑酸鹼重複性 42
3-3 有機染劑pKa值估算 43
3-4 FRET 效率比較 44
3-5 半導體高分子奈米顆粒的尺寸 45
3-6 水相反應的鑑定 46
3-7 酸鹼探針最佳化時間以及校正曲線 47
3-8 MTT 細胞毒性測試以及細胞胞吞實驗 50
第四章 結論 52
第三部分 發展一基於半導體高分子奈米顆粒結合Heptamethine cyanine 近紅外光染劑作為螢光探針，偵測穀胱甘肽的含量 53
第一章 前言 53
第二章 實驗 54
2-1 實驗藥品 54
2-2 實驗儀器 55
2-3 合成部分 57
第三章 結果與討論 62
3-1有機染劑單體的光譜討論 62
3-2有機染劑單體對硫醇的反應性 64
第四章 結論 65
第四部份 參考資料 66
附圖 73
第一部分 73
1H NMR of 1,2,3,3-tetramethyl-3H-indolium iodide，1a 73
1H NMR of 2-(2-[2-Chloro-3-([1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene]ethylidene)-1-cyclohexen-1-yl]ethenyl)-1,3,3-trimethylindolium iodide，1b 74
1H NMR of 3,5-dibromo-5-(2-bromoethoxy)benzene，2a 75
1H NMR of 1-(2-(3,5-dibromophenoxy)ethyl)piperazine，2b 76
1H NMR of 2-((E)-2-((E)-2-(4-(2-(3,5-dibromophenoxy)ethyl)piperazin-1-yl)-3-(2-((E)-1,3,3-trimethylindolin-2-ylidene)ethylidene)cyclohex-1-en-1-yl)vinyl)-1,3,3-trimethyl-3H-indol-1-ium iodide，2c 77
1H NMR of tert-butyl (4-hydroxyphenethyl)carbamate，3a 78
1H NMR of tert-butyl (4-(3-bromopropoxy)phenethyl)carbamate，3b 79
1H NMR of tert-butyl (4-(3-(piperazin-1-yl)propoxy)phenethyl)carbamate，3c 80
1H NMR of 2-((E)-2-((E)-2-(4-(3-(4-(2-((tert-butoxycarbonyl)amino)ethyl)phenoxy)propyl)piperazin-1-yl)-3-(2-((E)-1,3,3-trimethylindolin-2-ylidene)ethylidene)cyclohex-1-en-1-yl)vinyl)-1,3,3-trimethyl-3H-indol-1-ium iodide，3d 81
1H NMR of 2-((E)-2-((E)-2-(4-(3-(4-(2-aminoethyl)phenoxy)propyl)piperazin-1-yl)-3-(2-((E)-1,3,3-trimethylindolin-2-ylidene)ethylidene)cyclohex-1-en-1-yl)vinyl)-1,3,3-trimethyl-3H-indol-1-ium iodide，3e 82
Mass of tert-butyl (4-(3-bromopropoxy)phenethyl)carbamate，3b 83
Mass of tert-butyl (4-(3-(piperazin-1-yl)propoxy)phenethyl)carbamate，3c 84
Mass of 2-((E)-2-((E)-2-(4-(3-(4-(2-((tert-butoxycarbonyl)amino)ethyl)phenoxy)propyl)piperazin-1-yl)-3-(2-((E)-1,3,3-trimethylindolin-2-ylidene)ethylidene)cyclohex-1-en-1-yl)vinyl)-1,3,3-trimethyl-3H-indol-1-ium iodide，3d 85
Mass of 2-((E)-2-((E)-2-(4-(3-(4-(2-aminoethyl)phenoxy)propyl)piperazin-1-yl)-3-(2-((E)-1,3,3-trimethylindolin-2-ylidene)ethylidene)cyclohex-1-en-1-yl)vinyl)-1,3,3-trimethyl-3H-indol-1-ium iodide，3e 86
第二部分 87
1H NMR of 2,5-dioxopyrrolidin-1-yl 3,5-dibromobenzoate，4a 87
1H NMR of tert-butyl (2-aminoethyl)carbamate，4b 88
1H NMR of tert-butyl (2-(3,5-dibromobenzamido)ethyl)carbamate，4c 89
1H NMR of 2-(3,5-dibromobenzamido)ethan-1-aminium 2,2,2-trifluoroacetate，4d 90
1H NMR of (E)-4-((4-hydroxyphenyl)diazenyl)benzoic acid，4e 91
1H NMR of 2,5-dioxopyrrolidin-1-yl (E)-4-((4-hydroxyphenyl)diazenyl)benzoate，4f 92
1H NMR of (E)-N-(2-((3,5-dibromophenyl)amino)ethyl)-4-((4-hydroxyphenyl)diazenyl)benzamide，4g 93
1H NMR of 2-((1E)-2-((3E)-2-(4-((4-((2-(3,5-dibromobenzamido)ethyl)carbamoyl)phenyl)diazenyl)phenoxy)-3-(2-((E)-1,3,3-trimethylindolin-2-ylidene)ethylidene)cyclohex-1-en-1-yl)vinyl)-1,3,3-trimethyl-3H-indol-1-ium，4h 94
Mass of 2-((1E)-2-((3E)-2-(4-((4-((2-(3,5-dibromobenzamido)ethyl)carbamoyl)phenyl)diazenyl)phenoxy)-3-(2-((E)-1,3,3-trimethylindolin-2-ylidene)ethylidene)cyclohex-1-en-1-yl)vinyl)-1,3,3-trimethyl-3H-indol-1-ium，4h 95

1. Massey, M.; Wu, M.; Conroy, E. M.; Algar, W. R., Mind your P's and Q's: the coming of age of semiconducting polymer dots and semiconductor quantum dots in biological applications. Curr Opin Biotechnol 2015, 34, 30-40.
2. Sahoo, H., Förster resonance energy transfer – A spectroscopic nanoruler: Principle and applications. Journal of Photochemistry and Photobiology C: Photochemistry Reviews 2011, 12 (1), 20-30.
3. Whitten, S. T.; Garcia-Moreno, E. B.; Hilser, V. J., Local conformational fluctuations can modulate the coupling between proton binding and global structural transitions in proteins. Proc Natl Acad Sci U S A 2005, 102 (12), 4282-7.
4. Pérez-Sala, D.; Collado-Escobar, D.; Mollinedo, F., Intracellular alkalinization suppresses lovastatin-induced apoptosis in HL-60 cells through the inactivation of a pH-dependent endonuclease. J Biol Chem. 1995, 270 (11), 6235-42.
5. Lagadic-Gossmann, D.; Huc, L.; Lecureur, V., Alterations of intracellular pH homeostasis in apoptosis: origins and roles. Cell Death Differ 2004, 11 (9), 953-61.
6. Miksa, M.; Komura, H.; Wu, R.; Shah, K. G.; Wang, P., A novel method to determine the engulfment of apoptotic cells by macrophages using pHrodo succinimidyl ester. J Immunol Methods 2009, 342 (1-2), 71-7.
7. Lakadamyali, M.; Rust, M. J.; Babcock, H. P.; Zhuang, X., Visualizing infection of individual influenza viruses. Proceedings of the National Academy of Sciences 2003, 100 (16), 9280-9285.
8. Yao, S.; Schafer-Hales, K. J.; Belfield, K. D., A new water-soluble near-neutral ratiometric fluorescent pH indicator. Organic letters 2007, 9 (26), 5645-5648.
9. Pancera, S. M.; Gliemann, H.; Schimmel, T.; Petri, D. F., Effect of pH on the adsorption and activity of creatine phosphokinase. The Journal of Physical Chemistry B 2006, 110 (6), 2674-2680.
10. Lee, M. H.; Han, J. H.; Lee, J. H.; Park, N.; Kumar, R.; Kang, C.; Kim, J. S., Two‐Color Probe to Monitor a Wide Range of pH Values in Cells. Angewandte Chemie International Edition 2013, 52 (24), 6206-6209.
11. Dennis, A. M.; Rhee, W. J.; Sotto, D.; Dublin, S. N.; Bao, G., Quantum dot–fluorescent protein FRET probes for sensing intracellular pH. ACS nano 2012, 6 (4), 2917-2924.
12. Myochin, T.; Kiyose, K.; Hanaoka, K.; Kojima, H.; Terai, T.; Nagano, T., Rational design of ratiometric near-infrared fluorescent pH probes with various pKa values, based on aminocyanine. J Am Chem Soc 2011, 133 (10), 3401-9.
13. Hassan, S. S.; Rechnitz, G., Determination of glutathione and glutathione reductase with a silver sulfide membrane electrode. Analytical Chemistry 1982, 54 (12), 1972-1976.
14. Forman, H. J.; Zhang, H.; Rinna, A., Glutathione: overview of its protective roles, measurement, and biosynthesis. Molecular aspects of medicine 2009, 30 (1), 1-12.
15. Dalton, T. P.; Shertzer, H. G.; Puga, A., Regulation of gene expression by reactive oxygen. Annual review of pharmacology and toxicology 1999, 39 (1), 67-101.
16. Anderson, M. E., Determination of glutathione and glutathione disulfide in biological samples. Methods in enzymology 1985, 113, 548-555.
17. Estrela, J. M.; Ortega, A.; Obrador, E., Glutathione in cancer biology and therapy. Critical reviews in clinical laboratory sciences 2006, 43 (2), 143-181.
18. Chen, X.; Zhou, Y.; Peng, X.; Yoon, J., Fluorescent and colorimetric probes for detection of thiols. Chemical Society Reviews 2010, 39 (6), 2120-2135.
19. Jung, H. S.; Chen, X.; Kim, J. S.; Yoon, J., Recent progress in luminescent and colorimetric chemosensors for detection of thiols. Chemical Society Reviews 2013, 42 (14), 6019-6031.
20. Jiang, X.; Yu, Y.; Chen, J.; Zhao, M.; Chen, H.; Song, X.; Matzuk, A. J.; Carroll, S. L.; Tan, X.; Sizovs, A., Quantitative imaging of glutathione in live cells using a reversible reaction-based ratiometric fluorescent probe. ACS chemical biology 2015, 10 (3), 864-874.
21. Zhang, Y.; Shao, X.; Wang, Y.; Pan, F.; Kang, R.; Peng, F.; Huang, Z.; Zhang, W.; Zhao, W., Dual emission channels for sensitive discrimination of Cys/Hcy and GSH in plasma and cells. Chemical Communications 2015, 51 (20), 4245-4248.
22. Tang, B.; Xing, Y.; Li, P.; Zhang, N.; Yu, F.; Yang, G., A rhodamine-based fluorescent probe containing a Se− N bond for detecting thiols and its application in living cells. Journal of the American Chemical Society 2007, 129 (38), 11666-11667.
23. Guo, Z.; Park, S.; Yoon, J.; Shin, I., Recent progress in the development of near-infrared fluorescent probes for bioimaging applications. Chemical Society Reviews 2014, 43 (1), 16-29.
24. Brenner, D. J.; Hall, E. J., Computed tomography—an increasing source of radiation exposure. New England Journal of Medicine 2007, 357 (22), 2277-2284.
25. Lim, S. Y.; Shen, W.; Gao, Z., Carbon quantum dots and their applications. Chem Soc Rev 2015, 44 (1), 362-81.
26. Wu, C.; Chiu, D. T., Highly fluorescent semiconducting polymer dots for biology and medicine. Angew Chem Int Ed Engl 2013, 52 (11), 3086-109.
27. Yu, J.; Rong, Y.; Kuo, C. T.; Zhou, X. H.; Chiu, D. T., Recent Advances in the Development of Highly Luminescent Semiconducting Polymer Dots and Nanoparticles for Biological Imaging and Medicine. Anal Chem 2017, 89 (1), 42-56.
28. Lim, S. Y.; Shen, W.; Gao, Z., Carbon quantum dots and their applications. Chemical Society Reviews 2015, 44 (1), 362-381.
29. Wu, C.; Szymanski, C.; McNeill, J., Preparation and Encapsulation of Highly Fluorescent Conjugated Polymer Nanoparticles. Langmuir 2006, 22, 2956-2960.
30. Wu, C. B., B.; Szymanski, C.; Christensen, K.; McNeill, J. ACS Nano 2008, 2, 2415, Multicolor Conjugated Polymer Dots for Biological Fluorescence Imaging. ACS Nano 2008, 2, 2415-2423.
31. Wu, C.; Schneider, T.; Zeigler, M.; Yu, J.; Schiro, P. G.; Burnham, D. R.; McNeill, J. D.; Chiu, D. T., Bioconjugation of Ultrabright Semiconducting Polymer Dots for Specific Cellular Targeting. Journal of the American Chemical Society 2010, 132, 15410-15417.
32. Wu, C.; Hansen, S. J.; Hou, Q.; Yu, J.; Zeigler, M.; Jin, Y.; Burnham, D. R.; McNeill, J. D.; Olson, J. M.; Chiu, D. T., Design of Highly Emissive Polymer Dot Bioconjugates for In Vivo Tumor Targeting. Angewandte Chemie International Edition 2011, 50 (15), 3430-3434.
33. Ye, F.; Wu, C.; Jin, Y.; Chan, Y.-H.; Zhang, X.; Chiu, D. T., Ratiometric Temperature Sensing with Semiconducting Polymer Dots. Journal of the American Chemical Society 2011, 133 (21), 8146-8149.
34. Chan, Y. H.; Wu, C.; Ye, F.; Jin, Y.; Smith, P. B.; Chiu, D. T., Development of ultrabright semiconducting polymer dots for ratiometric pH sensing. Anal Chem 2011, 83 (4), 1448-55.
35. Childress, E. S.; Roberts, C. A.; Sherwood, D. Y.; LeGuyader, C. L.; Harbron, E. J., Ratiometric fluorescence detection of mercury ions in water by conjugated polymer nanoparticles. Anal Chem 2012, 84 (3), 1235-9.
36. Wu, P. J.; Chen, J. L.; Chen, C. P.; Chan, Y. H., Photoactivated ratiometric copper(II) ion sensing with semiconducting polymer dots. Chem Commun (Camb) 2013, 49 (9), 898-900.
37. Huang, Y.-C.; Chen, C.-P.; Wu, P.-J.; Kuo, S.-Y.; Chan, Y.-H., Coumarin dye-embedded semiconducting polymer dots for ratiometric sensing of fluoride ions in aqueous solution and bio-imaging in cells. J. Mater. Chem. B 2014, 2 (37), 6188-6191.
38. Kuo, S. Y.; Li, H. H.; Wu, P. J.; Chen, C. P.; Huang, Y. C.; Chan, Y. H., Dual colorimetric and fluorescent sensor based on semiconducting polymer dots for ratiometric detection of lead ions in living cells. Anal Chem 2015, 87 (9), 4765-71.
39. Xu, W.; Lu, S.; Xu, M.; Jiang, Y.; Wang, Y.; Chen, X., Simultaneous imaging of intracellular pH and O2using functionalized semiconducting polymer dots. J. Mater. Chem. B 2016, 4 (2), 292-298.
40. Chan, Y.-H.; Wu, P.-J., Semiconducting Polymer Nanoparticles as Fluorescent Probes for Biological Imaging and Sensing. Particle & Particle Systems Characterization 2015, 32 (1), 11-28.
41. Hong, G.; Antaris, A. L.; Dai, H., Near-infrared fluorophores for biomedical imaging. Nature Biomedical Engineering 2017, 1 (1), 0010.
42. Xu, Y.; Liu, Y.; Qian, X., Novel cyanine dyes as fluorescent pH sensors: PET, ICT mechanism or resonance effect? Journal of Photochemistry and Photobiology A: Chemistry 2007, 190 (1), 1-8.
43. 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), 7018-25.
44. JE, W.; RP, H.; FG, P., Spectral and photophysical studies of benzo[c]xanthene dyes: dual emission pH sensors. Anal Biochem. 1991, 194 (2), 330-344.