Two near-infrared（NIR） p H-activated heptamethine indocyanine probes with quaternary ammonium unit were designed and synthesized. The absorption and emission titrations indicate that cationic structure improves the ...Two near-infrared（NIR） p H-activated heptamethine indocyanine probes with quaternary ammonium unit were designed and synthesized. The absorption and emission titrations indicate that cationic structure improves the cyanine dye＇s aqueous solubility and these two probes exhibit highly sensitive response to p H in acid condition. Their fluorescence intensities both gradually increase about 25-fold from p H 7.60 to 3.00 with p Ka values of 4.72 and 4.45 respectively, which are suitable for studying acidic organelles in living cells. Moreover, their fluorescence intensities are linearly proportional to p H values in the range of 5.50–4.00. These results are probably attributed to the protonation of the indole nitrogen atoms, which are verified by 1H NMR spectra. Furthermore, these two probes can achieve real-time imaging of cellular p H and detection of p H in situ in living He La cells due to their excellent properties,including good reversibility, desirable photostability, high selectivity, low cytotoxicity and remarkable membrane permeability.展开更多
Four derivatives of 9,10-bis[2-（2-alkoxynaphthalen-1-yl）vinyl]anthracene（BNAs） were designed,successfully synthesized and characterized by spectrofluorometer, powder wide-angle X-ray diffraction（PXRD） and differ...Four derivatives of 9,10-bis[2-（2-alkoxynaphthalen-1-yl）vinyl]anthracene（BNAs） were designed,successfully synthesized and characterized by spectrofluorometer, powder wide-angle X-ray diffraction（PXRD） and differential scanning calorimetry experiments（DSC）, etc. It was found that these compounds exhibited aggregation-induced emission phenomenon. Moreover, these target compounds displayed reversible color change from yellow to orange upon pressing and annealing process. Interestingly, all of BNAs obviously presented red-shifted piezofluorochromic（PFC） properties and behaved mainly length dependence of alkoxy group, in which, BNA displayed the largest PFC spectral shift（DlPFC= 26 nm）. The PXRD profiles demonstrated the transformation from crystalline to amorphous state upon grinding, and the mechanism of PFC behaviors was proposed. Thus, changing the length of alkoxyl chain could be an alternative way to tune their PFC behaviors.展开更多
基金financial support from the National Natural Science Foundation of China(No.21576194)
文摘Two near-infrared（NIR） p H-activated heptamethine indocyanine probes with quaternary ammonium unit were designed and synthesized. The absorption and emission titrations indicate that cationic structure improves the cyanine dye＇s aqueous solubility and these two probes exhibit highly sensitive response to p H in acid condition. Their fluorescence intensities both gradually increase about 25-fold from p H 7.60 to 3.00 with p Ka values of 4.72 and 4.45 respectively, which are suitable for studying acidic organelles in living cells. Moreover, their fluorescence intensities are linearly proportional to p H values in the range of 5.50–4.00. These results are probably attributed to the protonation of the indole nitrogen atoms, which are verified by 1H NMR spectra. Furthermore, these two probes can achieve real-time imaging of cellular p H and detection of p H in situ in living He La cells due to their excellent properties,including good reversibility, desirable photostability, high selectivity, low cytotoxicity and remarkable membrane permeability.
基金financial support from the National Natural Science Foundation of China(No.21576194)
文摘Four derivatives of 9,10-bis[2-（2-alkoxynaphthalen-1-yl）vinyl]anthracene（BNAs） were designed,successfully synthesized and characterized by spectrofluorometer, powder wide-angle X-ray diffraction（PXRD） and differential scanning calorimetry experiments（DSC）, etc. It was found that these compounds exhibited aggregation-induced emission phenomenon. Moreover, these target compounds displayed reversible color change from yellow to orange upon pressing and annealing process. Interestingly, all of BNAs obviously presented red-shifted piezofluorochromic（PFC） properties and behaved mainly length dependence of alkoxy group, in which, BNA displayed the largest PFC spectral shift（DlPFC= 26 nm）. The PXRD profiles demonstrated the transformation from crystalline to amorphous state upon grinding, and the mechanism of PFC behaviors was proposed. Thus, changing the length of alkoxyl chain could be an alternative way to tune their PFC behaviors.
