School of Chemical and Biomedical Engineering, Nanyang Technological University, 637457, Singapore.
ACS Appl Mater Interfaces. 2013 Jun 26;5(12):5856-60. doi: 10.1021/am401528w. Epub 2013 Jun 10.
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.
我们展示了一种新颖的方法来制备基于荧光的 pH 传感器，该方法结合了 Ag 核的等离子体共振带和 pH 敏感染料（HPTS）。在 Ag 核和 HPTS 染料之间放置一层厚度可变的二氧化硅壳，以实现最大的荧光增强。当壳厚为 8nm 时，当传感器分别在 405nm 和 455nm 激发时，荧光强度分别增加了 4 倍和 9 倍。同时，荧光强度对 pH 值在 5-9 范围内具有良好的灵敏度，并且确定了在 455nm 激发时发射强度在 513nm 处与在 405nm 激发时的比率与 pH 值在 5-9 范围内的关系。相信这种 pH 传感器具有实时测定生物样品中 pH 值的潜力。
