Study On The Construction And Detection Performance Of Melon Ring/dye Fluorescent Probe

Fluorescence spectroscopy has been applied to quantitative analysis drugs or pesticides due to its inherent sensitivity. Cucurbit[n]urils(referred to as Q[n]), as a new macrocyclic host molecule, are not easy to change their shape for its structural rigidity and shows high chemical stability compared with cyclodextrin and calixarene.Cucurbit[n]urils have great potentials application in molecular recognition and supramolecular chemistry. In this paper, tricyclic basic dyes, such as proflavine(PF),pyronine Y(PYY), acridine orange(AO), was choosed to form fluorescence probes with cucurbit[8]uril(Q[8]) based on the molecular recognition. Supramolecular fluorescent probes have been developed to recognize pesticides(benzimidazole fungicides) or drugs(gefitinib, lapatinib ditosylate and L-Borneol) by converting Q[8]-dye complexations. Then the influence of pH, reaction time and interfering substances on fluorescent probes were investigated. The research contents are as follows:The interaction of cucurbit[8]uril(Q[8]) with thionine(TH) and benzimidazole fungicides(fuberidazole(FBZ), thiabendazole(TBZ), carbendazim(CBZ) and2-aminobenzimidazole(2-BZ)) were investigated by fluorescence and UV–vis spectroscopy. The experimental results showed that inclusion complex between Q[8]and TH informed at molar ratios of 1:2. The fluorescence intensity of the TH-Q[8]complexes quenched when Q[8] was added to TH solution, but fluorescence increasing of the 2TH@Q[8] complex with the addition of benzimidazole fungicides was observed and showed differences in the color. The fluorescence increasing values showed a good linear relationship with FBZ, TBZ, CBZ, 2-BZ concentration. The detection limit was as low as 10-7~10-8mol/L. The results revealed that complexation of Q[8] and TH with benzimidazole fungicides offers a fluorescent switching “on-off”effect which will supply a potential application in pesticide residues test.Firstly, based on the interaction of Q[8] with tricyclic basic dyes(proflavine(PF),pyronine Y(PYY), acridine orange(AO)), 2PF@Q[8], 2PYY@Q[8] and 2AO@Q[8]fluorescent probes were established. Host-guest interaction between fluorescentprobes and two tyrosine kinase inhibitors, namely gefitinib(GEF) and lapatinib ditosylate(LD) were also explored. The results showed that the fluorescence intensity of PF, PYY or AO was quenched when Q[8] was added to a solution of dyes and recovered when tyrosine kinase inhibitors(GEF, LD) was added to the three fluorescence probes mixture. We found a linear correlation between fluorescent probes and concentration of tyrosine kinase inhibitors. The detection limit is as low as10-7~10-8mol/L. The selectivity of the three fluorescence probes complex were investigated. The presence of another tyrosine kinase inhibitors, drug excipients and biological fluids ions, did not substantially affect the detection of drugs, indicating that the probes shows excellent selectivity for drugs. The three fluorescence probes was shown to be suitable for imaging GEF and LD in prostate cancer(PC3) cells,which may help to elucidate relevant biological processes at the molecular level.The supramolecular interaction of the cucurbit[7]uril(Q[7]), hemimethylsubstituted cucurbit[7]uril(HMeQ[7]) and cucurbit[8]uril(Q[8]) with L-Borneol showed a stable host-guest complexation which the ratio is 1:1. We used the fluorescence probe 2PF@Q[8] for sensing the L-Borneol by fluorescence, UV–vis spectroscopy and cell imaging. The results showed that the fluorescence probe2PF@Q[8] can be used for sensing the L-Borneol. We found a linear correlation between fluorescent probes and concentration of L-Borneol from(0-300)×10-8 mol/L.The detection limit was as low as 5.52×10-8 mol/L. The applicability of the developed fluorescence probe was evaluated by determining the concentration of L-Borneol in samples. The concentrations of L-Borneol determined using the proposed fluorescence probe were consistent with those obtained by HPLC. The fluorescence probe was shown to be suitable for imaging L-Borneol in prostate cancer(PC3) cells.