Study On The Detection Performance Of Aroma Pollutants By Cucurbitacin Supramolecular Sensor Arra

Along with the development of science and technology and the continuous improvement of people’s living standards,the pollutants released into the environment from industrial and agricultural production are increasing,and the problem of environmental pollution has gradually developed into a worldwide problem,causing great concern to the public in various countries.Environmental pollutants often coexist with other chemically similar substances,especially when the pollutants show structural and property similarities,it is a challenge to detect and distinguish the target pollutants.Aromatic pollutants belong to a class of compounds with high stability and hazards,which are difficult to biodegrade.Due to the complex composition and similar structure of aromatic pollutants in the environment,their differentiation and detection become an urgent problem,and it is important to develop simple,fast and cost-effective detection technologies.Optical sensing arrays came into being,and the most common optical sensing arrays are colorimetric and fluorescence sensing arrays.The method is based on the principle of bionic design and uses arrays composed of broad-spectrum cross-response sensing units in conjunction with pattern recognition algorithms for detection,with the ability to detect and monitor analytes in complex mixtures.Cucurbit[n]urils（Q[n]s）are macrocyclic compounds with hydrophobic cavities surrounded by carbonyl groups,whose hydrophobic cavities are electrically neutral and have a wrapping effect on the guest molecule.The cross-reactivity and lack of specificity of melon ring-object interaction are suitable for the design of sensing array systems.Based on the difference of affinity of melon ring/object probes for multi-component pollutants,we designed and constructed melon ring supramolecular sensing arrays to study the recognition and response performance of melon ring supramolecular sensing arrays for multi-component pollutants,and provide an experimental basis for the detection of aromatic pollutants with complex compositions.The main research contents and results of this thesis are as follows:1)The host-guest interactions between cucurbit[8]uril（Q[8]）and three electron-deficient guests(MV²⁺,VCN²⁺,MVE²⁺)were studied.Q[8]formed 1:1 stoichiometric host-guest complexes with three guests(MV²⁺@Q[8],VCN²⁺@Q[8],MVE²⁺@Q[8]).The supramolecular colorimetric sensing array was constructed with the above three host-guest probes as three sensing units,and six structurally similar aniline and phenol contaminants were used as the target analytes to be measured,among which p-phenylenediamine（p-PD）,m-phenylenediamine（m-PD）and o-phenylenediamine（o-PD）are three isomers of phenylenediamine;resorcinol（RS）and hydroquinone（HQ）are two dihydroxybenzene m-AP is a homologue of benzylamine and dihydroxybenzene.The response behavior of this colorimetric sensing array to six structurally similar aniline and phenol pollutants was systematically investigated.It was found that the presence of the six aniline and phenol contaminants caused different degrees of color changes in the UV-visible absorption spectra of the probes and in natural light,and the RGB color change values of each sensing unit in response to the contaminants were extracted and combined with linear discriminant analysis（LDA）to achieve the identification and differentiation of the six aniline and phenol contaminants;the sensitivity of the colorimetric array for contaminant identification was tested The sensitivity of the colorimetric array for pollutant identification was tested,and it was found that the colorimetric array achieved the identification and differentiation of different pollutant concentrations,and the total Euclidean distance（TED）of the array showed a good linear correlation with the pollutant concentration,and the detection limit was 10^-5-10^-6 M.The ability of the colorimetric array to identify binary,ternary and quaternary pollutant mixtures was tested,and it was found that the colorimetric array was good at It was found that the colorimetric sensing array could classify the binary,ternary and quaternary pollutant mixtures well.Also,the applicability of the colorimetric sensing array in real samples was investigated,and it was found that the colorimetric sensing array classified six aniline and phenol pollutants well in river water.By analyzing the contribution of each sensing unit to the array and gradually reducing the number of sensing units,it was found that one sensing unit could also effectively distinguish the six contaminants and achieve the simplification of the sensing array.Finally,the NMR spectroscopy results show that the guest and the contaminants form electron transfer complexes within the cavity of the eight-membered melon ring,which results in different color responses of the probes to the six contaminants mentioned above due to the differences in the contaminants.This method can achieve rapid identification and quantification of multiple aromatic pollutants simultaneously.2)White luminescent supramolecular complexes were obtained by varying the molar ratio of BMZ to 2C30@3Q[8]complexes,using the host-guest complex（2C30@3Q[8]）of cucurbit[8]uril with coumarin 30（C30）as the yellow fluorescent substance and benzimidazole（BMZ）as the purple fluorescent substance.The white-emitting supramolecular complex showed two fluorescence emission spectra at 370 nm and 526 nm,and the change of each emission band can be regarded as a signal channel.A two-channel white light sensing array was constructed accordingly.When structurally similar nitroaniline isomeric contaminants（p-nitroaniline（p-NA）,m-nitroaniline（m-NA）and o-nitroaniline（o-NA））were added to this white light-emitting supramolecular complex,the white light-emitting supramolecular complex produced a unique dual-channel signal pattern for each analyte,allowing the identification and differentiation of the three nitroaniline isomers.The sensitivity of the white light sensing array for the identification of nitroaniline was tested,and it was found that the white light sensing array achieved the identification and differentiation of different concentrations of pollutants,and the Factor 1 of the array showed a good linear correlation with the concentration of pollutants,with a detection limit of 10-7 M.The ability of the white light sensing array to identify mixtures of binary and ternary pollutants was tested,and it was found that the white light sensing array classified well the It was found that the white light sensing array could well classify the binary and ternary pollutant mixtures.The applicability of the white light sensing array in real samples was also investigated,and the white light sensing array was found to classify three nitroaniline isomers well in river water.In addition,the possibility of qualitative detection of nitroaniline residues in aquatic plants was investigated,and the results showed that the white light sensing array could qualitatively identify the contaminants in rice seedling extracts in qualitative analysis.Finally,the interaction between BMZ and 2C30@3Q[8]was investigated using ¹H NMR,and the results of NMR spectroscopy showed that the guest and contaminants formed electron transfer complexes within the melon ring cavity,and the white light emission was attributed to the increased green emission of the2C30@Q[8]complex,the decreased yellow emission of 2C30@3Q[8]and the new C30@BMZ@Q[8]charge transfer complexes were formed.Compared with conventional sensing arrays,the white light sensing array provides the same amount of information but reduces the complexity of analytical operations,providing an ideal platform for the construction of multi-response sensors.3)In the previous chapter,it was found that after the addition of benzimidazole（BMZ）to the 2C30@3Q[8]host-guest complex,the color of the system changed from yellow to white to green with a rich fluorescent color change.Accordingly,in this chapter,2C30@3Q[8]was used as a fluorescent probe to detect and differentiate three structurally similar benzimidazole pesticide（FBZ,CBZ,TBZ）contaminants,and when the three benzimidazole pesticides were added,the color of the solution changed under the irradiation of UV lamp at 254 nm,according to which a supramolecular colorimetric sensing array was constructed to extract the sensing units in response to the pesticide after The sensitivity of the colorimetric array for pesticide identification was tested,and the Euclidean distance（ED）of the array showed a good linear correlation with the pesticide concentration,and the detection limit was 10^-7 M.The sensitivity of the colorimetric array for pesticide identification was tested.The colorimetric sensing array was tested for the recognition of binary and ternary pesticide mixtures,and it was found that the colorimetric sensing array classified the binary and ternary pesticide mixture pollutants well.The applicability of the colorimetric sensing array in real samples was also investigated,and it was found that the colorimetric sensing array classified three benzimidazole pesticides well in river water.The method can achieve rapid identification and quantification of three structurally similar benzimidazole pesticides simultaneously.