Disposable and Low-cost Free Chlorine Sensor Based on Pencil Drawn Paper Electrode

Abstract

This is the first alternative analysis of pencil drawn paper electrode for free available chlorine (FAC) detection. It is one of the new technologies for fabricating simple, low lost, portable and disposable analytical device for many application areas including clinical diagnosis, food quality control and environmental monitoring. In this work a complete analysis of physical and electrochemical properties of pencil graphite electrode (POE) and pencil drawn paper electrode (PDPE) has been performed to detect FAC in surface water. Cyclic voltammetry (CV) and amperometry were used to study the electro-catalytic properties. Excellent catalytic activity has been obtained for free chlorine detection using both POE and PDPE with a sensitivity of 121 ± 5.38 .iAmMcm 2 and 36 ± 3.65 pAmM4cm 2 respectively and a linearity range up to 12 mM and 7 mM for both platforms respectively. Also limit of detection POE and PDPE has been found to be 59.5 and 88.9 p.M respectively. There is no response obtained for common interfering ions in surface water such as NO3 , SO 2 , C0 32 , Cl'and HCO3 . Both the sensors were evaluated for their storage stability and response time and thereby can be applied as a low-cost electrochemical sensor for determining FAC in surface water. The unique properties of this sensor allow the passive liquid transport and compatibility with chemical/biochemical are the main advantage of using this sensing platform. In addition, this sensor could better meet the current objectives of a viable low cost and portable device in addition to offering high sensitivity, selectivity and multiple analyte discrimination.