Application of Prussian Blue in Electrochemical and Optical Sensing of Free Chlorine

In this paper, an electrochemical free chlorine (FCL) sensor was formed by modifying a fluorine-doped tin oxide-coated glass slide (glass vertical bar FTO) with a layer of Prussian blue (glass vertical bar FTO vertical bar PB). The glass vertical bar FTO vertical bar PB sensor exhibited a wide linear detection range from 1.7 to 99.2 mu mol L-1 of FCL with a sensitivity of similar to 0.8 mu A cm(-2) mu mol(-1) L and showed high selectivity for FCL. However, ClO3-, ClO(4)(- )and NO3- ions have induced only a negligible amperometric response that is highly beneficial for a real-life sample analysis as these ions are commonly found in chlorine-treated water. Moreover, in this work, optical absorption measurement-based investigations of partially reduced PB were carried out as a means to characterize PB catalytic activity towards FCL and to investigate the possibility of applying PB for the optical detection of FCL.

Automated summary

In this paper, an electrochemical free chlorine sensor was developed by modifying a fluorine-doped tin oxide-coated glass slide with a layer of Prussian blue. The sensor exhibited a wide linear detection range and high selectivity for free chlorine. Additionally, optical absorption measurement-based investigations were conducted to evaluate the catalytic activity of Prussian blue and its potential for optical detection of free chlorine.