Sensitive and environmental friendly sensor on porphyrin functionalized chitosan fiber membrane for Hg2+
Yafei Ma, Xinman Liu, Zhiping Fu, Lifen Zhang, Yuexin Guo, Hui Wang, Zhiqian Jia
Abstract
Mercury is the most toxic and harmful heavy metal pollutant, and it is essential to detect and remove mercury from beverages. Inducing the porphyrin molecules into the chitosan structure, a novel membrane sensor tetrakis(4-carboxyphenyl)porphyrin-grafted chitosan fiber membrane (TCPP-CS) was prepared by electrospinning method and applied to recognize Hg 2+ contaminant selectively. Compared with other common metal ions (Pb 2+ , Cu 2+ , Fe 3+ , Cr 3+ , Mg 2+ , and Zn 2+ ), the colorimetric sensor has specific color development and sensitivity to Hg 2+ and the detection limit of the sensor reaches 1 × 10 −5 mol·L −1 . The response time of the membrane is 5 s, and it can be specifically colored in various pH environments convenient for practical application. Hg 2+ resulted in a visual color change of the fiber membrane from brown to yellow-green, indicating a potential interaction between the porphyrin-functionalized chitosan fiber membrane and Hg 2+ ions, and the wavelength shift of the UV–visible spectrum can be observed. It has the advantages of simplicity, rapidity, high selectivity, and high sensitivity, providing a new method for removing and detecting heavy metals in traditional Chinese medicine and drinks.