一种新型比率荧光毛细管pH传感器的制备及性能

Preparation of a Novel Ratiometric Fluorescent Capillary-based pH Sensor

实时便捷的pH检测对于环境监测和医学诊断等领域具有重要应用价值。本文通过溶胶-凝胶法制备了一种比率荧光毛细管pH传感器。该传感器以2.8-羟基芘-1,3,6-三磺酸三钠盐(8-hydroxy-pyrene-1,3,6-tri-sulfonate,HPTS)作为pH敏感的荧光探针,利用HPTS与十六烷基三甲基溴化铵(hexadecyl trimethyl ammonium bromide,CTAB)结合形成HPTS-IP离子对,然后将离子对分散于溶胶-凝胶中,并将其固定于毛细管内壁即制得比率荧光毛细管pH传感器。该传感器利用HPTS在双激发带下的发射强度比值实现比率荧光检测,当pH从5.0上升至8.0时,HPTS的荧光强度比率随pH值增加逐渐增强,pKa值为6.95,通过分析HPTS的比率荧光强度变化可间接监测pH波动。该传感器具有较好的pH敏感性、稳定性和可逆性,且可快速、灵活、便捷地进行实际操作,在环境保护和生物医学领域的pH监测分析方面拥有良好的应用前景。

Real-time and convenient pH detection plays an important role in environmental monitoring,medical di-agnosis and other fields.In this paper,a ratiometric fluorescent capillary-based pH sensor was prepared by sol-gel method.The sodium 8-hydroxy-pyrene-1,3,6-trisulfonate(HPTS)acts as a pH sensitive fluorescent probe,and combines with hexadecyl trimethyl ammonium bromide(CTAB)to form HPTS-IP ion pairs.Then the ion pairs were dispersed in the sol-gel,and further fixed in the inner wall of capillary to obtain the ratiometric fluorescent capillary pH sensor.Based on the dual excitation bands of HPTS,the referenced excitation ratiometric sensor is realized.When the pH value rises from 5 to 8,the fluorescence intensity ratio of HPTS gradually increases with the increase of pH,with a pKa value of 6.95.By analyzing the changes in fluorescence intensity ratio of HPTS,pH can be indirect-ly detected.This sensor has high pH sensitivity,good stability,and excellent reversibility,which can be applied quickly,flexibly,and conveniently in practical operations.All in all,it is promising in pH monitoring at environ-mental protection and biomedical fields.