The Fluorescent/Electrochemical Sensors Based On Pillararenes Supramolecular Recognition And Its Application In Detection Of Disease Markers

Pillararenes are a novel class of macrocyclic molecules with hydroquinone as the repeating unit linked by methylene bridges at para-positions.As the fifth-generation macro-supramolecular host compound,it has been widely used in various fields,such as molecular recognition,self-assembly,supramolecular catalysis,drug delivery and so on.However,their applications for fluorescent and electrochemical sensors is rarely reported.In the study of this paper,the sensors based on CP6,rPA5 and CP5 were developed,and applied for the detection of insulin,cholesterol,and dopamine with fluorescence or electrochemistry methods.Compared with other traditional analysis technology such as HPLC,MS,CL,the sensors have some out-standing advantages,its have potential application in the practical detection.This dissertation is made up following three parts.(1)CP6 were synthetized according to corresponding literature reports,and CP6@RGO composites were prepared by a simple one-step reaction.The synthesis of CP6 and the preparation of complexes were determined by NMR,FTIR,TGA,AFM,?-potential and XPS.A sensitive and selective fluorescence approach based on a competitive host–guest interaction between CP6 and signal probe RhB,target molecule insulin was developed by using CP6@RGO as a receptor.The host-guest interaction was studied by fluorescence titration and molecular docking.The low detection limit of0.003 ?M and a linear response range of 0.01-0.5 ?M and 0.5-16 ?M for insulin was obtained by using this method that demonstrates a practical application for the sensitive and selective detection of insulin in serum samples.(2)Synthesis of rPA5 for the stabilization and reduction of chloroauric acid preparation of gold nanoparticles solution rPA5-AuNPs,a sensitive and selective fluorescence approach based on a competitive host–guest interaction between rPA5 and signal probe RhB,target molecule cholesterol was developed.The fluorescence analysis of the linear range of the sensor was 0.01-0.5 ?M and 0.5-16 ?M,and the detection limitof 6.5 nM.The method is used for detecting cholesterol in real serum samples,and the recovery range is 95.3%-103.5%.(3)The CP5@RGO nanocomposite was prepared by a wet-chemical method in aqueous solution and characterized by FTIR,TGA,XPS,AFM and EDX.The host–guest interaction between CP5 and DA was studied by fluorescence titration and molecular modeling calculations.A novel electrochemical sensing platform has been developed towards DA detection based on competitive host–guest interaction by selecting methylene blue(MB)and CP5@RGO as the “reporter pair”.Upon the presence of DA to the performed CP5@RGO·MB complex,the MB molecules are displaced by DA,leading to a “switch off” electrochemical response.The proposed competitive electrochemical sensing platform was successfully used to determine DA in serum samples.