Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : FITC and Ru(phen)32+ co-doped silica particles as visualized ratiometric pH indicator | Xu et al. Nanoscale Research Letters 2011 6 561 http content 6 1 561 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access FITC and Ru phen 32 co-doped silica particles as visualized ratiometric pH indicator Jianquan Xu1 Lei Sun2 Jun Li1 Jinglun Liang1 Huimao Zhang3 and Wensheng Yang1 Abstract The performance of fluorescein isothiocyanate FITC and tris 1 10-phenanathroline ruthenium ion Ru phen 32 co-doped silica particles as pH indicator was evaluated. The emission intensity ratios of the pH sensitive dye FITC and the reference dye Ru phen 32 in the particles were dependent on pH of the environment. The changes in emission intensity ratios of the two dyes under different pH could be measured under single excitation wavelength and readily visualized by naked eye under a 365-nm UV lamp. In particular such FITC and Ru phen 32 co-doped silica particles were identified to show high sensitivity to pH around the pKa of FITC making them be potential useful as visualized pH indicator for detection of intracellular pH micro-circumstance. Keywords pH indicator visualized silica particles ratiometric fluorescein ruthenium complex Background In recent years ratiometric fluorescent pH indicators had been developed for sensitive detection of pH of an analyte 1-6 . To fabricate a ratiometric pH indicator usually two dyes one pH sensitive and one reference dyes were incorporated into a silica or polymer matrix. In this approach a core shell architecture in which the reference dye was mainly located in the core and the pH-sensitive dye located primarily in the shell was preferred 2 7 . The ratios in emission intensity of the two dyes were correlated to pH of the analyte. Compared to pH indicator containing only the pH-sensitive dye 8-13 such ratiometric pH indicator was more reliable since the ratios in emission intensity were less sensitive to the fluctuations in excitation light source intensity and variations in other .
