Development of non-specific chemical sensors based on nanostructured polymeric films for the detection of methylisoborneol and geosmin

• Grant number: 18/12496-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2018
• End date: April 30, 2019
• Field of knowledge: Engineering - Electrical Engineering
• Agreement: SABESP
• Principal Investigator: Fernando Josepetti Fonseca
• Grantee: Pedro Germano Almeida Machado
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Company: Universidade de São Paulo (USP). Escola Politécnica (EP)
• Associated research grant: 13/50440-7 - Online water quality analysis (ACQUA-OnLine), AP.PITE

Abstract

The present study proposes the development of non-specific sensors to detect methylisoborneol (MIB) and geosmin (GEO) in real water samples. Water samples originate from Guarapiranga dam and SABESP water treatment plants (ETAs). The presence of these compounds in the water causes unpleasant taste and odor, being necessary to remove them from the water or to reduce their concentration to levels not perceivable by the population. These sensors are formed by gold microelectrodes coated with nanostructured polymers. Organic films are deposited by the technique of self-assembly via electrostatic attraction and interrogated under alternating current regime. The database collected by the electronic tongue will be analyzed by Principal Components Analysis (PCA) method. These sensors have already been successfully applied in the detection of MIB and GEO in artificially contaminated tap water samples. This study intends to make a systematic evaluation of these sensors, by analyzing their sensitivity to the compounds, durability, reproducibility of measurements and the effect of interferents. After the measurements, it will determine whether it will be necessary to perform a cleaning with diluted acids, detergents or other types of cleaning solutions other than ultrapure water. At the end of this study it is expected to obtain non-specific sensors with high sensitivity to MIB and GEO that will be incorporated into a hybrid system containing specific and non-specific sensors that will be used to monitor in real time and in loco the water quality of dams and of ETAs of the metropolitan region of São Paulo.