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A HPU-23@Ru@Tb-NH2 sensor array with light-driven oxidase-mimicking activity and triple-emission fluorescence was developed. It was composed of a Tb3+-functionalized metal organic framework and Ru(bpy)32+ and applied to the simultaneous detection of Hg2+, ClO−, and PO43− via differently responsive channels. HPU-23@Ru@Tb-NH2 had a photoresponsive colorimetric response toward Hg2+ with a LOD as low as 4.18 nM. In addition, the three emissions of the HPU-23@Ru@Tb-NH2 sensor array were influenced by ClO− and PO43− to varying degrees, causing remarkably distinguishable responses for the fluorescence channels to discriminate ClO− and PO43− from each other. The detection limits of ClO− and PO43− were 12.26 µM and 0.197 nM, respectively. Therefore, this work demonstrates the feasibility of multi-emission and multi-mode sensing platform, which is able to combine the advantages of different strategies for solving the problems of various toxic substances coexisting in the environment while meeting the needs of accurate and precise results and no side interferences. [ABSTRACT FROM AUTHOR]

C24H20N10O2Cu, orthorhombic, Aba2 (no. 41), a = 12.2281(16) Å, b = 19.176(3) Å, c = 9.8689(13) Å, V = 2314.1(5) Å3, Z = 4, Rgt(F) = 0.0381, wRref(F2) = 0.0752, T = 296(3) K.

In this work, a novel composite material (HPU-24@Ru) has been prepared by combining a blue-emission Cd-based metal-organic framework (MOF, [Cd2(TCPE)(DMF)(H2O)3]n, HPU-24) with a red-emission tris (2,2′-bipyridine) dichlororuthenium(II) hexahydrate ([Ru(bpy)3]2+) molecule for ratiometric fluorescence sensing of Al3+ ions in aqueous medium and high-level dynamic anticounterfeiting application. The luminescence measurement results indicated that the fluorescence intensity of HPU-24 at 446 nm showed a red shift in the presence of Al3+ ions, and the new peak appeared at 480 nm and continued to increase with an increase in Al3+ ion concentration. Meanwhile, the fluorescence intensity of [Ru(bpy)3]2+ almost showed no change. The detection limit was calculated as 11.63 μM, which was better than that for the MOF-based Al3+ ions in some reported examples in aqueous media and achieved through strong electrostatic interactions between HPU-24@Ru and Al3+ ions. Moreover, owing to the particularity of the tetrastyryl structure in HPU-24, HPU-24@Ru showed intriguing temperature-dependent emission behavior. This unique structure provides the composite material HPU-24@Ru with attributes for high-level information encryption that make it difficult for counterfeiters to identify all of the right decryption measures. [ABSTRACT FROM AUTHOR]

A new composite material CsPbBr3@HPU-22 was prepared by using {[Zn2(ADDA)2(DMF)(H2O)2]·(DMF)}n (HPU-22) as a carrier to encapsulate CsPbBr3 in channels. The obtained composite material has high sensitivity to water. Under the stimulation of a humid environment or water vapor, the color of the CsPbBr3@HPU-22 product can be seen to turn from yellow to white. In addition, it is necessary to note that the changed color could recover after drying. A study of the mechanism demonstrated that the inter-conversion between CsPbBr3 and CsPb2Br5 is the major reason for this reversible color change during the wetting and drying process. In addition, CsPbBr3@HPU-22 also exhibited high sensitivity to acid–base gases, accompanied by a change in fluorescence color under UV light. The evidence showed that the protonation of DMF molecules might result in the reversible response of CsPbBr3@HPU-22 to acid–base gases. Therefore, the multi-response to water and acid–base gas stimulation gives the CsPbBr3@HPU-22 applications in the field of high-level anti-counterfeiting. [ABSTRACT FROM AUTHOR]

Smart fluorescent materials that respond to external stimuli have received more and more attention because of their excellent optical properties in the field of anti-counterfeiting, information security and fluorescence sensing. Herein, we reported a new stimulus-responsive material, {[Zn4(TCPE)(HTCPE)(DMA)3(OH)(H2O)2]·2DMA·2H2O}n (HPU-21), which showed a series of fluorescence changes under the influence of temperature, pressure and solvents. Combined with the temperature-dependent fluorescence, 1H NMR and 13C NMR spectra, TEM and powder X-ray diffraction results, the fluorescence transformation was mainly attributed to the changes in the twisted ethyl core and the multiple rotational phenyl rings, as well as the aggregation degree. Based on these findings, we designed an adjustable formaldehyde probe with excellent performance. The detection limit of formaldehyde in aqueous solutions is calculated as 35 ppb, which is much lower than the concentration that is harmful to health (20 ppm). The extremely high sensitivity to formaldehyde makes it have potential application prospects in practical formaldehyde detection. [ABSTRACT FROM AUTHOR]