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Copper ions are known to be very important for homeostasis, which is critical for the metabolism and development of living organisms. In addition, sulfide ions, as an important endogenously produced gasotransmitter, have been proved to be implicated in a variety of physiological functions such as anti-apoptosis, vasodilation, antioxidation, and anti-inflammation. Herein, we report the development of a novel fluorescence chemosensor (L) based on a tetra-peptide conjugated with dansyl groups as a promising analytical tool for detecting Cu2+ and S2− in 100% aqueous solutions, which exhibits excellent cell biotoxicity and intracellular biosensing ability. The chemosensor L displays an “on–off–on” response type fluorescence change upon the addition of Cu2+ and S2− to aqueous media and living cells. Moreover, L displays high selectivity and sensitivity with the detection limits for Cu2+ and S2− measured to be 88 nM and 75 nM, respectively. This study raises the new possibility of a highly selective and sensitive peptide-based fluorescence chemosensor for multifunctional detection, including cation and anions, using a successive fluorescence response strategy in environmental and biological systems. [ABSTRACT FROM AUTHOR]

Manganese dioxide formed in oxidation process by potassium permanganate exhibits promising adsorptive capacity which can be utilized to remove organic pollutants in wastewater. However, the structure variances of organic molecules lead to wide difference of adsorption efficiency. Therefore, it is of great significance to find a general relationship between removal rate of organic compounds and their quantum parameters. This study focused on building up quantitative structure activity relationship (QSAR) models based on experimental removal rate ( r) of 25 organic compounds and 17 quantum parameters of each organic compounds computed by Gaussian 09 and Material Studio 6.1. The recommended model is r = −0.502 − 7.742 f(+) + 0.107 E + 0.959 q(H) + 1.388 BO. Both internal and external validations of the recommended model are satisfied, suggesting optimum stability and predictive ability. The definition of applicability domain and the Y-randomization test indicate all the prediction is reliable and no possibility of chance correlation. The recommended model contains four variables, which are closely related to adsorption mechanism. f(+) reveals the degree of affinity for nucleophilic attack. E represents the difficulty of electron loss. q(H) reflect the distribution of partial charge between carbon and hydrogen atom. BO shows the stability of a molecule. [ABSTRACT FROM AUTHOR]

Copper ions are known to be very important for homeostasis, which is critical for the metabolism and development of living organisms. In addition, sulfide ions, as an important endogenously produced gasotransmitter, have been proved to be implicated in a variety of physiological functions such as anti-apoptosis, vasodilation, antioxidation, and anti-inflammation. Herein, we report the development of a novel fluorescence chemosensor (L) based on a tetra-peptide conjugated with dansyl groups as a promising analytical tool for detecting Cu 2+ and S 2- in 100% aqueous solutions, which exhibits excellent cell biotoxicity and intracellular biosensing ability. The chemosensor L displays an "on-off-on" response type fluorescence change upon the addition of Cu 2+ and S 2- to aqueous media and living cells. Moreover, L displays high selectivity and sensitivity with the detection limits for Cu 2+ and S 2- measured to be 88 nM and 75 nM, respectively. This study raises the new possibility of a highly selective and sensitive peptide-based fluorescence chemosensor for multifunctional detection, including cation and anions, using a successive fluorescence response strategy in environmental and biological systems.