Retraction of "Robust Chemiresistive Sensor for Continuous Monitoring of Free Chlorine using Graphene-Like Carbon".

Abstract

Free chlorine is widely used in industry as a bleaching and oxidizing agent. Its concentration is tightly monitored to avoid environmental contamination and deleterious human health effects. Here, we demonstrate a solid state chemiresistive sensor using graphene like carbon (GLC) to detect free chlorine in water. A 15-20 nm thick GLC layer on a PET substrate was modified with a redox-active aniline oligomer (phenyl-capped aniline tetramer, PCAT) to increase sensitivity, improve selectivity and impart fouling resistance. Both the bare GLC sensor and the PCAT-modified GLC sensor can detect free chlorine continuously and unlike previous chemiresistive sensors, do not require a reset. The PCAT-modified sensor showed a linear response with a slope of 13.89 (mg/L)-1 to free chlorine concentrations between 0.2 to 0.8 mg/L which is relevant for free chlorine monitoring for drinking water and waste water applications. The PCAT-modified GLC sensors were found to be selective and showed less than 0.5% change in curr...