【ACS Appl. Mater. Interfaces】Fluorescent pH Sensor Based on Ag@SiO2 Core–Shell Nanoparticle
writer：Bai Zhenhua; Chen Rui; Si Peng; Huang Youju; Sun Handong; Kim Dong-Hwan*
keywords：Core–Shell Nanoparticle
source：期刊
specific source：ACS Appl. Mater. Interfaces 2013, 5, 5856?5860
Issue time：2013年
We have demonstrated a novel method for the preparation of a fluorescence-based pH sensor by combining the plasmon resonance band of Ag core and pH sensitive dye (HPTS). A thickness-variable silica shell is placed between Ag core and HPTS dye to achieve the maximum fluorescence enhancement. At the shell thickness of 8 nm, the fluorescence intensity increases 4 and 9 times when the sensor is excited at 405 and 455 nm, respectively. At the same time, the fluorescence intensity shows a good sensitivity toward pH value in the range of 5?9, and the ratio of emission intensity at 513 nm excited at 455 nm to that excited at 405 nm versus the pH value in the range of 5?9 is determined. It is believed that the present pH sensor has the potential for determining pH real time in the biological sample.