Fluorescence imaging of intracellular cadmium using a dual-excitation ratiometric chemosensor.
ABSTRACT We described here a coumarin-based dual-excitation ratiometric probe for cadmium, CadMQ. This fluorescence sensor has high quantum yields of 0.59 and 0.70 in the metal-free and Cd2+-bound forms, respectively, and has a dissociation constant of 0.16 nM for Cd2+. CadMQ is cell permeable and locates within the acidic compartments of the cells. We further show that CadMQ is a useful tool to ratiometrically probe the change in the intracellular Cd2+ levels with the use of two excited wavelengths.
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ABSTRACT: A novel simple C3v-symmetric, completely water soluble quinoline based guanidinium Schiff's base system have been reported for the selective detection of Cd2+ in physiological environment through a turn-on fluorescence response. The cadmium complex is found to be highly selective toward iodide by turning off the fluorescence through the sequestration of Cd2+ from L1-Cd by the precipitation of CdI2. Detection limit for Cd2+ and iodide are found to be 51 ppb and 1 ppb, respectively. L1 is reversible toward Cd2+ and iodide and can be recycled. The receptor was used for the detection of Cd2+ in complex natural samples (tap, lake and river water).Sensors and Actuators B Chemical 12/2014; 204:474. · 3.84 Impact Factor
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ABSTRACT: This article describes a green synthetic approach to prepare water dispersible perovskite-type Eu(3+) -doped KZnF3 nanoparticles, carried out using environmentally friendly microwave irradiation at low temperature (85 °C) with water as a solvent. Incorporation of Eu(3+) ions into the KZnF3 matrix is confirmed by strong red emission upon ultraviolet (UV) excitation of the nanoparticles. The nanoparticles are coated with poly(acrylic acid) (PAA), which enhances the dispersibility of the nanoparticles in hydrophilic solvents. The strong red emission from Eu(3+) ions is selectively quenched upon addition of Cu(II) ions, thus making the nanoparticles a potential Cu(II) sensing material. This sensing ability is highly reversible by the addition of ethylenediaminetetraacetic acid (EDTA), with recovery of almost 90 % of the luminescence. If the nanoparticles are strongly attached to a positively charged surface, dipping the surface in a Cu(II) solution leads to the quenching of Eu(3+) luminescence, which can be recovered after dipping in an EDTA solution. This process can be repeated for more than five cycles with only a slight decrease in the sensing ability. In addition to sensing, the strong luminescence from Eu(3+) -doped KZnF3 nanoparticles could be used as a tool for bioimaging.Chemistry - A European Journal 02/2014; · 5.93 Impact Factor
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ABSTRACT: The complete remediation of extremely toxic elements, such as cadmium, must be achieved to control the various stages in their life cycles, from mining as virgin ore to using them as consumer and industrial end products, and recycling. Considerable progress has been made in monitoring cadmium ions, but sensors or captors that can simultaneously detect and remove toxic metal ions across a wide range of environments are still greatly needed. This article reviews the tools and the strategies for the environmental remediation of cadmium ions, with special emphasis on state-of-the-art colorimetric sensors. Selective colorimetric sensors based on immobilization of hydrophobic or hydrophilic chromophore molecules into nanosized space cavities have significant advantages because of their dual functionality, namely, early warning “detection” and removal of cadmium ions. This review concludes with a thorough evaluation of emerging challenges and future requirements in monitoring, detecting, and removing cadmium ions from environmental matrices.TrAC Trends in Analytical Chemistry 11/2014; · 6.35 Impact Factor