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.

Improved Photophysical Properties of Ionic Material-Based Combination Chemo/PDT Nanomedicine

“…These materials are highly thermally stable and tunable in their chemical and photophysical properties. Therefore, they have been explored for multiple applications. − ILs are highly tunable where both counterions can be easily exchanged to fit specific applications. The cationic nitrogen and phosphorus-based ILs have gained attention in regards to their chemotherapeutic activity. − Some of the ILs show cytotoxicity toward normal cells, which has restricted their use for medical applications.…”

Cationic Porphyrin-Based Ionic Nanomedicines for Improved Photodynamic Therapy

“…7,20 Using the IM approach, the small spectator counterion can be replaced with a bulky ion to improve the photophysical properties by preventing aggregation in porphyrins. Several distinct IMs have been developed for a variety of applications such as cancer therapy, 7 sensors, 21 extraction chemistry, 22 energy, 23 etc. Several anionic porphyrins have been converted into IMs.…”

“…Recently, a new class of materials known as ionic materials (IMs) has gained much attention due to their high thermal and photostability, tunability, and formation of stable nanoparticles. − Unlike organic synthesis which involves multistep reactions, IMs are easily synthesized through a cost-effective and reproducible ion exchange method with high product yield. , Using the IM approach, the small spectator counterion can be replaced with a bulky ion to improve the photophysical properties by preventing aggregation in porphyrins. Several distinct IMs have been developed for a variety of applications such as cancer therapy, sensors, extraction chemistry, energy, etc. Several anionic porphyrins have been converted into IMs. ,,, However, to the best of our knowledge, no cationic porphyrin has been used before to develop IMs.…”