In this study, parallelogram-like macrocyclic supramolecular metallacycles [Pd₆(bpy)₆(L¹)₄](PF₆)₈ (1a) and [Pd₆(bpy)₆(L²)₄](PF₆)₈ (2a), where HL¹=1-(1H-pyrazole-4-yl)-4-(4-pyridyl)benzene, HL²=9-(1H-pyrazole-4-yl)-10-(4-pyridyl)anthracene, and bpy=2, 2'-bipyridine, are synthesized by reacting aryl pyrazole pyridine ligands with dipalla-dium corners in aqueous solutions via metal-directed hierarchical self-assembly. The structures of the supramolecular Pd parallelograms are confirmed through single-crystal X-ray diffraction. Notably, the two parallelogram metallacycles can be used as"turn-on"fluorescence sensors to detect HSO₃^- through a disassembly mechanism. In addition, the 1a-based sensor shows selective detection of HSO₃^- without interference from other anions. The detection limit was as low as 0.131 μmol·L^-1. Furthermore, complex 1a presented the semiquantitative visual detection ability for HSO₃^- in the test trip mode via fluorescence changes.

以生物质橙子皮为原料，通过简单的一步水热法制备了橙子皮基碳量子点(orange peel-based carbon quantum dots，OP-CQDs)，并用荧光分析法对其性质进行了研究。结果表明，OP-CQDs水溶性好、荧光强、在生理pH范围内性能稳定。OP-CQDs对铁离子(Fe³⁺)有特异性猝灭反应且灵敏度高，同时，L-抗坏血酸(L-ascorbic acid，L-AA)能够使OP-CQDs-Fe³⁺体系的荧光部分恢复，形成了“开-关-开”的荧光检测体系。Fe³⁺和L-AA的检出限分别为1.1和31.8 μmol·L^-1。