摘要
设计合成了一种引入多个氯原子取代的耐光漂白的碳菁型pH荧光探针(CyCl4),在500 nm波长光的激发下,该探针具有530和596 nm两个波长的荧光峰,其中的596 nm荧光峰在pH 8.5环境中具有最高的荧光信号值,在pH<8.1和>9.8的条件下则荧光很弱,通过密度泛函方法计算这三种荧光状态分别对应的三种构象结构A,B和C,而结构B中的两个磺酸基构成分子内氢键而具有共面性几何构型,共轭程度最好,因而其荧光发射能力最强.测量了该探针的荧光量子产率、瞬态荧光光谱和耐光漂白性能,其耐光漂白性能强于一般染料型荧光探针.最后将该探针应用于前列腺癌活细胞荧光成像,并发现其在细胞膜表面的聚集现象.
The pH-dependence fluorescence monitoring probes are of great significance and play many critical roles in studying of cells, enzymes, and tissue activities, including proliferation, apoptosis, multidrug resistance, ion transportation, endocytosis, and muscle contraction etc. Here a carbocyanine type anti-photobleaching pH fluorescence probe was synthe sized in which four chlorine atoms were substituted. The probe had two fluorescent peaks at the wavelengths of 530 nm and 596 nm respectively under the irradiation at the excited wavelength of 500 nm. The fluorescent emission at 596 nm indicated a large stokes shift of 96 nm and the strongest value at the pH value of 8.5, and the fluorescent emission was very weak at the pH values of 〈8.1 or 〉9.8. Then three conflgurational structures as A, B and C were proposed accordingly, which were further confirmed through calculation by the density functional theory in the Gaussian 03 soft package. The coplanarity of the structure B was found which was contributed by the intramolecular hydrogen bond between two sulfonic acid groups. The coplanarity thus led to the higher conjugation system in the molecule structure and the stronger fluorescence emission. The fluorescence quantum yield was measured as 0.35 by the relative measuring method and the transient fluorescence spectra were determined as well. In the photobleaching test, the probe showed a good anti-photobleaching performance with the sta- ble time of more than 70 min, which was much better than the traditional organic probes. The anti-photobleaching perform ance was good enough to ensure the wide application in biology imaging. The fluorescence images of PANC-1 cells stained by the probe （1 μmol/L） incubated in PBS buffer solution were obtained by the inverted fluorescence microscope. The probe was found aggregated onto the cell-membrane during cell differentiation and proliferation processes.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2013年第10期1435-1440,共6页
Acta Chimica Sinica
基金
国家自然科学基金(No.21074033)资助~~
关键词
碳菁染料
光漂白
PH荧光探针
细胞成像
carbocyanine dyes
photobleaching
pH fluorescence probe
cell imaging
