Reagent-Free Quantification of Aqueous Free Chlorine via Electrical Readout of Colorimetrically Functionalized Pencil Lines

• DOI: 10.1021/acsami.7b03968
• Publication Date: 2017-06-07T19:35:12Z
• Authors: Amirmasoud Mohtasebi; Andrew D. Broomfield; Tanzina Chowdhury; P. Ravi Selvagana...; Peter Kruse
• Keywords: Chlorate

Colorimetric methods are commonly used to quantify free chlorine in drinking water. However, these not suitable for reagent-free, continuous, and autonomous applications. Here, we demonstrate how functionalization of a pencil-drawn film with phenyl-capped aniline tetramer (PCAT) can be quantitative electric readout concentrations. The functionalized implemented simple fluidic device continuous sensing aqueous sensor is selective undergo reagent-free reset further measurements. Our superior electrochemical that it does require reference electrode. It capable quantification the range 0.1–12 ppm higher precision than colorimetric (absorptivity) methods. interactions PCAT upon exposure hypochlorite were characterized spectroscopically. A previously reported detection mechanism relied on measurement baseline shift new method demonstrated here measures initial spike size chlorine. relies fast charge built up due intermittent salt formation. has advantage being significantly faster shift, but cannot detect gradual changes concentration without use frequent pulses. stability was examined presence as function pH. While most ions present water do interfere detection, other oxidants may contribute signal. easy fabricate robust, operates very low power requirements thus remote deployment.