Construction Of Nanochannels Modified By Pillar[5]Arene And The Researches Of Transmission Behavior

In life,cells exchange material with their surroundings all the time.They need not only a wide variety of substances,but also different natures.The basic scaffold that constitutes the cell membrane is the phospholipid bilayer.There are very few substances that can directly enter and exit the cell through the phospholipid bilayer.The entry and exit of most substances is related to the structure,characteristics and other factors of the cell membrane.The substances that diffuse into and out of the cell by free diffusion are mainly affected by the difference in the concentration of ions or ions inside and outside the cell membrane.Most of the substances passing through the cell membrane need to be transported by means of carrier proteins and channel proteins on the cell membrane.The transfer of matter in the living body is particularly important in terms of material exchange,signal transmission,energy conversion,and system function control.However,the instability of biological pathways and the dependence on the environment make it difficult to carry out research on the transmission of matter.Therefore,it is necessary to develop a new research method.In recent years,artificial nanochannels have been closely watched by researchers because the chemical and physical properties of artificial nanochannels are stable,and their channel surfaces are easy to modify,which has extensive research value.Researchers have developed various functional nanochannels modified by functional groups for the detection,transmission and separation of small molecules.Among them,the introduction of macrocyclic supramolecular compounds into artificial nanochannels to construct artificial nanochannels with host-guest system for the specific detection of certain small molecules and the separation and transport of chiral molecular pairs and isomers have become Research hotspots.We will use this nanochannel with host and guest system to carry out research on the following two topics:1.N-acetylglucosamine is an important monosaccharide molecule in life.Moreover,studies have shown that N-acetylglucosamine in the human body is closely related to some major physiological diseases such as Alzheimer's disease and diabetes.In particular,the change of the concentration of N-acetylglucosamine in the blood directly affects the development of the human condition.Therefore,the detection of N-acetylglucosamine,especially in the human body,is very important.Therefore,we synthesized a tryptophan-derived pillar[5]arene according to the characteristics of N-acetylglucosamine.Subsequently,we modified this macrocyclic molecule into artificial nanochannels and tested the N-acetylglucosamine in potassium chloride solution.The experimental results show that the tryptophan pillar[5]arene-modified artificial nanochannel can detect N-acetylglucosamine.In addition,we have also realized the detection of N-acetylglucosamine in serum samples.The principle of detecting N-acetylglucosamine on this tryptophan pillar[5]arene modified nanochannel is that the tryptophan pillar[5]arene are capable of selectively binding N-acetylglucosamine molecules in the nanochannel,thereby causing Changes in hydrophilicity within the channel.The change from hydrophilic to hydrophobic in the channel causes a change in ion transport in the channel,which is macroscopically measured as a change in the measured current,thus enabling detection of N-acetylglucosamine.The successful construction of this channel provides a new research idea for people to develop intelligent artificial nanochannels.2.Xylene is the main component of the petroleum fraction C8,which is an important raw material in chemical production.It is widely used as a thinner for pigments,paints,etc.Xylene has three isomers,namely p-xylene,o-xylene and meta-xylene,which all play important roles in industrial production,especially para-xylene,which is industrially produced of starting material for a polyester compound.Therefore,the separation of mixed xylenes,especially the separation of para-xylene,is particularly important.We designed and synthesized a thioglycolic acid pillar[5]arene and modified this pillar[5]arene molecule into the alumina membrane nanochannel.Next,we investigated the transport properties of this channel for three xylene isomers.The experimental results show that the channel can transport para-xylene at a faster rate,and the transmission speed of para-xylene is more than twice the transmission speed of meta-xylene.Regarding the difference in the transport speed of this molecule,we speculate that the reason is that the mercaptoacetic acid pillar[5]arene has a stronger interaction with p-xylene,so that p-xylene can be preferentially transported.The construction of this channel helps people to further understand the law of mixed xylene transport separation.