Photoreduced Ag/sodium alginate supramolecular hydrogel as a sensitive SERS membrane substrate for rapid detection of uranyl ions.

Background: In the fields of environmental monitoring and nuclear emergency, in order to obtain the relevant information of uranyl-induced environmental pollution and nuclear accident, it is necessary to establish a rapid quantitative analytical technique for uranyl ions. As a new promising technique, surface-enhanced Raman scattering (SERS) is hopeful to achieve this goal. However, uranyl ions are easily desorbed from SERS substrates under acidic conditions, and the structures of SERS substrates will be destroyed in the strong acidic aqueous solutions.

Highly sensitive and selective determination of uranyl ions based on Ag/AgO-COF composite SERS substrate.

Uranium is an essential nuclear material in civilian and military areas; however, its extensive application raises concerns about the potential safety issues in the fields of environmental protection and nuclear industry. In this study, we developed an Ag/AgO-COF (covalent-organic framework) composite SERS substrate to detect uranyl ions (UO) in environmental aqueous solutions. Herein, the strong SERS effect of uranyl adsorbed in Ag/AgO composite and the high adsorption efficiency of COF TpPa-1 were combined to realize the trace detection of uranyl ions.

A novel synthesis of graphene quantum dots via thermal treatment of crude graphite oxide in a dry and alkaline condition, and their application in uranyl detection.

In this article, a novel method to synthesize graphene quantum dots was developed via thermal treatment of crude graphite oxide (GO) in a dry and alkaline condition to cut the crude GO sheets into small graphene quantum dots (named as aGQDs). The aGQDs are nano-scale reduced graphene oxide pieces with the sizes around 5-10 nm. The aGQDs could disperse in water for their richment of oxygen-containing groups.

Graphene quantum dot electrochemiluminescence increase by bio-generated HO and its application in direct biosensing.

In this study, a novel signal-increase electrochemiluminescence (ECL) biosensor has been developed for the detection of glucose based on graphene quantum dot/glucose oxidase (GQD/GO) on Ti foil. The proposed GQD with excellent ECL ability is synthesized through a green one-step strategy by the electrochemical reduction of graphene oxide quantum dot. Upon the addition of glucose, GO can catalytically oxidize glucose and the direct electron transfer between the redox centre of GO and the modified electrode also has been realized, which results in the bio-generated HO for ECL signal increase in GQD and realizes the direct ECL detection of glucose.

The physical chemistry of uranium (VI) immobilization on manganese oxides.

Manganese oxides show strong affinity towards uranium, and have a promising application in uranium immobilization in environmental protection. We successfully synthesized a series of Mn oxide materials of different structures and investigated their U(VI) immobilization performances. The results showed that all Mn oxides share similar sorption capacities per unit surface area, implying similar physical chemistry during immobilization.

Synthesis of sandwich-like MnO@reduced graphene oxide nano-composites via modified Hummers' method and its application as uranyl adsorbents.

Efficient and sustainable remediation technologies for uranium have recently been gaining more and more interest. Adsorption techniques are facile, effective and universal for kinds of heavy metal ions. In this paper, sandwich-like MnO@reduced graphene oxide (MnO@G) nano-composites were prepared facilely and greenly by adding NaOH solution into crude graphite oxide suspension prepared via the Hummers' method to modify the pH.

(4S,5S)-2-(4-Chloro-phen-yl)-1,3-dioxolane-4,5-dicarboxamide.

The title compound, C(11)H(11)ClN(2)O(4), is an important inter-mediate for the preparation of platinum anti-cancer drugs. The dioxolane ring adopts a twist conformation with an equatorially attached chloro-phenyl substituent. In the crystal structure, mol-ecules are linked into a two-dimensional network parallel to (001) by N-H⋯O and C-H⋯O hydrogen bonds.

(4S,5S)-2-(2-Bromo-phen-yl)-1,3-dioxolane-4,5-dicarboxamide.

The asymmetric unit of the title compound, C(11)H(11)BrN(2)O(4), contains two crystallographically independent mol-ecules in which the bromo-phenyl rings are oriented at dihedral angles of 39.28 (3)°. The dioxolane rings adopt envelope conformations.