| In recent years,compositing materials based on macrocycles（such as cyclodextri n,calixarene,cucurbit[n]uril and columnarene,etc.）and nanomaterials（such as graph ene,g-C3N4,metal nano,etc.）have been used in various fields.Especially in the field of supramolecular sensors,the compositing material combines the advantages of macr ocycles and nanomaterials to improve sensitivity and selectivity.Therefore,this paper constructed a chemical sensor,mainly used to detect diquat and chloramphenicol.The composites of benzo[6]uril-hybridized graphene oxide were prepared,and the full characterization of atomic force microscopy（AFM）,Infrared spectroscopy（IR）,and Raman spectroscopy,was employed.The materials exhibited dramatical improvement of the fluorescence response to the supramolecular interactions of umbelliferones with the macrocyclic compounds,and the encapsulation of the umbelliferone guests within the cavities of the macrocyclic hosts was confirmed by fluorescence titrations and molecular simulations.The applications of the supramolecular materials for quantitative determination of diquat gave the limits of detection of 3.4×10-7 mol·L-1and 5.0×10-7 mol·L-1,respectively,and high selectivity was evidenced in coexistence of other bipyridyl interferences including2,2’-bipyridine,4,4’-bipyridine,and methyl viologen in aqueous solutions.A new electrochemical sensor based on hemicucurbit[12]uril and reduced graphene oxide（r GO）was constructed,and the performance of the electrochemical sensor was investigated for the quantitative detection of Chloramphenicol（CAP）.Under the optimal conditions（5μL r GO,10μL Hemi Q[12],and the optimal incubation time of 10 mins）,the CAP solution was quantitatively detected,and the detection limit of 6.6×10-7 mol·L-1 was obtained.With the inferior LOD value to the previous reports,for further improve the sensitivity of determination for CAP,a novel photoelectrochemical sensor was constructed by ternary layer-by-layer composites of reduced graphene oxide（r GO）,graphitic carbon nitride quantum dots（g-C3N4 QDs）,and hemicucurbit[12]uril（Hemi Q[12]）,on ITO piece in sequence.Electrochemical Impedance Spectroscopy（EIS）was employed to confirm the successful assembly of the sandwich electrode,and the functionalization of each layer was explored by comparing of the currents with stepwise coating of the materials to achieve the synergistic enhancement of photoelectrochemical intensity.The application of proposed electrode was achieved by ultrasensitive sensing for CAP,which provided a limit of detection low to 8.9×10-11 mol·L-1,with high selectivity,good reproducibility and stability.The acceptable recoveries for the determination of CAP in real samples of honey and milk illustrated the feasibility of the established analytical method. |
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