Paper-Based Portable Sensor and Nanosensor For Sulfur Dioxide Detection

Abstract

Sulfur dioxide (SO2) pollution has become an increasing issue world-wide as it is produced both naturally and as industrial waste. Thus, it is critical to develop a sensor and detection methods to analyze SO2 in the atmosphere. In order to design and generate an effective sensor that detects low levels of SO2, fuchsine dyes have been used as a potential sensor material. New hydrophobic derivatives of Pararosaniline hydrochloride (pR-HCl) is developed to further improve the sensitivity of fuchsine dyes towards SO2 gas. It has been shown that these dyes can provide an economic and efficient colorimetric detection of SO2. In this work, (pR-HCl) is converted into an ionic material (IM) via a facile ion exchange reaction with bis (trifluoromethane) sulfonamide (NTF2) counterion. The new, hydrophobic derivative, pararosaniline bis (trifluoromethane) sulfonamide (pR-NTF2) IM was converted into stable aqueous ionic nanomaterials (INMs) by a reprecipitation method. Examination of absorption spectra results revealed that pR-NTF2 IM exhibits enhanced molar absorptivity in comparison to the parent dye (pR-HCl). The improved photophysical properties allowed a framework for a highly sensitive nanosensor for detection of SO2. A paper based portable SO2 sensor was also developed and tested for its ability to colorimetric detection of SO2. The cost effective and stable paper-based sensor exhibited the rapid response to decolorize the fuchsine dyes in few seconds as compared to their parent compound. Keywords: SO2 Detection, Portable and Low-cost Sensor, Nanosensor.