A PTZ-BODIPY based fluorescent chemosensor was designed and used for hypochlorite detection.

A highly water-soluble phenothiazine (PTZ)-boron dipyrromethene (BODIPY)-based electron donor-acceptor dyad (WS-Probe), which contains BODIPY as the signaling antennae and PTZ as the OCl reactive group, was designed and used as a fluorescent chemosensor for the detection of OCl . Upon addition of incremental amounts of NaOCl, the quenched fluorescence of WS-Probe was enhanced drastically, which indicated the inhibition of reductive photoinduced electron transfer (PET) from PTZ to BODIPY*; the detection limit was calculated to be 26.7 nm. Selectivity studies with various reactive oxygen species, cations, and anions revealed that WS-Probe was able to detect OCl selectively. Steady-state fluorescence studies performed at varied pH suggested that WS-Probe can detect NaOCl and exhibits maximum fluorescence in the pH range of 7 to 8, similar to physiological conditions. ESI-MS analysis and H NMR spectroscopy titrations showed the formation of sulfoxide as the major oxidized product upon addition of hypochlorite. More interestingly, when WS-Probe was treated with real water samples, the fluorescence response was clearly visible with tap water and disinfectant, which indicated the presence of OCl in these samples. The in vitro cell viability assay performed with human embryonic kidney 293 (HEK 293) cells suggested that WS-probe is non-toxic up to 10 μm and implicates the use of the probe for biological applications.

Energy is one of the main issues in this century. The demand of energy for usage of modern electronic accessories has attracted lot of attention towards energy storage devices such as batteries and supercapacitors. Supercapacitors have the greater potential for providing good cyclability, high power density and energy density as compared with the batteries [1][2][3]. The synthesis of advanced electrode materials for charge storage is the key issue in the development of supercapacitors. It has been found that pseudocapacitors are more efficient than electric double layer capacitors (EDLCs) and exhibit 10 times more capacitance-per-unit surface area for a given electrode material [4]. The energy density and power density of pseudocapacitors are usually several times larger than those of EDLCs [5]. RuO 2 was the first candidate that was employed as a pseudocapacitor which exhibited a capacitance of about 700 F g À1 , however showed limited application due to its scarcity and high cost [6]. Recently, the approach of combining battery electrode materials and electrochemical supercapacitors known as hybrid electrochemical supercapacitors (HESC) is being studied. They have been studied both in aqueous and non-aqueous electrolytes. Advantage of non-aqueous medium being a wide operating potential window (upto~4 V) as compared to aqueous (~1 V) [7]. [43] have been studied for supercapacitor and HESC. Different methodologies for synthesizing binary oxide of distinct morphologies have been reported [33][34][35][36][37][38][39][40][41][42][43]. Morphology affects the chemical, physical and electrochemical properties of the material. Solution combustion synthesis has the advantage of producing fine and homogeneous powder of high purity in a single step self propagating process at low temperature with high exothermicity [44][45][46][47]. Citric acid is used as fuel as it is inexpensive and is a more effective complexing agent. It is often accompanied with the addition of certain amounts of NH 4 OH which help to overcome drying stresses and contribute to the porosity and strength of the solÀgel network [44]. In this present study manganese iron oxide Abstract: Phase pure nanocrystalline manganese iron oxide [(Mn 0.37 Fe 0.63 ) 2 O 3 ] was synthesized by combustion technique based on propellant chemistry principle employing citric acid as fuel. The synthesized powder was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), BET, BJH analysis and electrochemical studies for possible application as a charge storage electrode. The average crystallite size was found to be 18.6 nm from XRD analysis. BET analysis yielded the surface area and specific pore volume of the powder to be 22.96 m 2 g À1 and 0.0098 cm 3 g À1 respectively. The specific capacitance from cyclic voltammetric studies at scan rate 5 mV s À1 was found to be about 30 F g À1 cm À2 while from charge discharge studies was found to be 27 AE 1 Fg À1 cm À2. In addition, the material showed appreciable stability during charge-discharge cycling.

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