Miniaturised and nanomodified printed electrochemical sensors

The aim of my PhD, funded by Tecnosens Spin-off, was the development of nanostructured sensors to control the quality of water for human consumption. Tecnosens was born in 2015 from the collaboration among the Etatron Company, the Department of Chemical Sciences and Technologies, in particular the Analytical Chemistry laboratory, and the Engineering Department of Tor Vergata University. The goal of the Spin-off was the production and the commercialisation of innovative, low cost, and miniaturised devices to monitor the concentration of disinfectant compounds in water treatment field. In particular, the selected compounds are free chlorine, chlorine dioxide, and peracetic acid. At the beginning, the research activity was aimed to the investigation of the commercially available amperometric probes, in order to understand their performances and the features of the flow systems on which the probes are installed. This study allowed the production, the installation of new sensor prototypes in swimming pool and drinking water facilities, and the selling of amperometric sensors produced by Tecnosens for free chlorine monitoring, based on gold bulk electrode. According to the purpose of Spin-off, two miniaturised amperometric sensors have been developed for free chlorine (Chapter 2) and chlorine dioxide (Chapter 3) detection in standard solution as well as in swimming pool water, exploiting the electrochemical features of carbon black nanomaterial as modifier of screen-printed electrodes. In order to replace the bulk electrodes of the sold probes, we have also taken advantages of gold-based screen-printed electrodes to detect free chlorine, chlorine dioxide and peracetic acid, to be combined with a selective membrane cap (Chapter 4). In recent years, paper has attracted attention in electrochemical field thanks to its fascinating properties, such as porosity and cheapness. In this scenario, paper support was investigated to print electrodes and to product cost-effective and user-friendly sensors for clinical and water quality applications. To meet the Spin-off needs of cost-effective and easy-to-use devices for an in-situ measurement, we have investigated the performances of gold nanoparticles-modified paperbased sensor for the indirect detection of free chlorine in water samples (Chapter 5). Furthermore, during my PhD, I also followed other research projects, such as the development of a reagent-free paper-sensor to measure glutathione. The developed device has given good results, demonstrating its capability to detect glutathione in blood samples for clinical application (Chapter 6).