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Ionic liquids are an interesting class of materials that have recently been utilized as chemotherapeutic agents in cancer therapy. Aniline blue, a commonly used biological staining agent, was used as a counter ion to trihexyltetradecylphosphonium, a known cytotoxic cation. A facile, single step ion exchange reaction was performed to synthesize a fluorescent ionic liquid, trihexyltetradecylphosphonium aniline blue. Aqueous nanoparticles of this hydrophobic ionic liquid were prepared using reprecipitationmethod. The newly synthesized ionic liquid and subsequent nanoparticles were characterized using various spectroscopic techniques. Transmission electron microscopy and zeta potential measurements were performed to characterize the nanoparticles’ morphology and surface charge. The photophysical properties of the nanoparticles and the parent aniline blue compound were studied using absorption and fluorescence spectroscopy. Cell viability studies were conducted to investigate the cytotoxicity of the newly developed trihexyltetradecylphosphonium aniline blue nanoparticles in human breast epithelial cancer cell line (MCF-7) and its corresponding normal epithelial cell line (MCF-10A) in vitro . The results revealed that the synthesized ionic nanomedicines were more cytotoxic (lower IC 50 ) than the parent chemotherapeutic compound in MCF-7 cells. Nanoparticles of the synthesized ionic liquid were also shown to be more stable in both aqueous and cellular media and more selective than parent compounds towards cancer cells. 

Herein, an ionic material (IM) with Förster Resonance Energy Transfer (FRET) characteristics is reported for the first time. The IM is designed by pairing a Nile Blue A cation (NBA+) with an anionic near-infrared (NIR) dye, IR820−, using a facile ion exchange reaction. These two dyes absorb at different wavelength regions. In addition, NBA+ fluorescence emission spectrum overlaps with IR820− absorption spectrum, which is one requirement for the occurrence of the FRET phenomenon. Therefore, the photophysical properties of the IM were studied in detail to investigate the FRET mechanism in IM for potential dye sensitized solar cell (DSSCs) application. Detailed examination of photophysical properties of parent compounds, a mixture of the parent compounds, and the IM revealed that the IM exhibits FRET characteristics, but not the mixture of two dyes. The presence of spectator counterion in the mixture hindered the FRET mechanism while in the IM, both dyes are in close proximity as an ion pair, thus exhibiting FRET. All FRET parameters such as spectral overlap integral, Förster distance, and FRET energy confirm the FRET characteristics of the IM. This article presents a simple synthesis of a compound with FRET properties which can be further used for a variety of applications. 

Herein, an inexpensive commercially available sensor is presented for the detection of 4-nitrophenol (4NP) pollutant. Sodium fluorescein (NaFl) is used as a sensor to detect trace amounts of 4NP in acetonitrile (MeCN). The photophysical properties of NaFl were studied in two different solvents, MeCN (aprotic) and water (protic), with varying concentrations of different nitroaromatics using UV-visible absorption and fluorescence spectrophotometry. In an aqueous medium, photophysical properties of NaFl did not change in the presence of nitroaromatics. However, examination of the photodynamics in MeCN demonstrated that NaFl is extremely sensitive to 4NP (limit of detection: 0.29 µg/mL). This extreme specificity of NaFl towards 4NP when dissolved in MeCN, as compared to other nitroaromatics, is attributed to hydrogen bonding of 4NP with NaFl in the absence of water, resulting in both static and dynamic quenching processes. Thus, NaFl is demonstrated as a simple, inexpensive, sensitive, and robust optical turn off sensor for 4NP. 

Combination nanodrugs are promising therapeutic agents for cancer treatment. However, they often require the use of complex nanovehicles for transportation into the tumor site. Herein, a new class of carrier-free ionic nanomaterials (INMs) is presented, which are self-assembled by the drug molecules themselves. In this regard, a photothermal therapy (PTT) mechanism is combined with a chemotherapy (chemo) mechanism using ionic liquid chemistry to develop a combination drug to deliver multiple cytotoxic mechanisms simultaneously. Nanodrugs were developed from an ionic material-based chemo-PTT combination drug by using a simple reprecipitation method. Detailed examination of the photophysical properties (absorption, fluorescence emission, quantum yield, radiative and non-radiative rate) of the INMs revealed significant spectral changes which are directly related to their therapeutic effect. The reactive oxygen species quantum yield and the light to heat conversion efficiency of the photothermal agents were shown to be enhanced in combination nanomedicines as compared to their respective parent compounds. The ionic nanodrugs exhibited an improved dark and light cytotoxicity in vitro as compared to either the chemotherapeutic or photothermal parent compounds individually, due to a synergistic effect of the combined therapies, improved photophysical properties and their nanoparticles’ morphology that enhanced the cellular uptake of the drugs. This study presents a general framework for the development of carrier-free dual-mechanism nanotherapeutics. 

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.