Recognition And Detection Of Drug Molecules Based On Single-molecule Conductance Measurement Technology

Molecular electronics is an important research field involving materials,engineering,chemistry and other disciplines.Its ultimate goal is to build single-molecule devices based on single molecules or molecular clusters to achieve the same functions as macro-electronic components.Among them,the study of the electron transport mechanism within the molecule is very important.Photoelectric molecules are a kind of organic macromolecules with"photoresponse",which have received extensive attention and research due to their special electron transport mechanism.This type of molecule can not only be adjusted by light to produce an order of magnitude difference in conductance,but also some photoelectric molecules themselves also have a fluorescent effect,which can be used for drug detection and tracking,which has great research significance.Briefly introduce the research progress of photochromic molecules,AIE（aggregation induced luminescence）molecules,solar molecules and other photoelectric molecules,and describe the molecular devices designed based on the electrical properties of photoelectric molecules,and explore the charge transport of photoelectric molecules from a theoretical perspective.The mechanism provides an effective basis at the single-molecule level for further probing the structure-activity relationship between the structure and properties of optoelectronic molecules and designing optoelectronic functional molecular devices.The scanning tunneling microscope consolidation method（STM-FJ）was used to detect a class of organic molecules with the characteristics of multi-channel transmission,and the detection of oxaliplatin and berberine were studied.Get the following conclusions:Subsequently,this study used scanning tunneling microscope consolidation method（STM-FJ）to detect a class of multi-channel transmission organic molecules,as well as two drug molecules,oxaliplatin and berberine.Get the following conclusions:（1）Conduct conductance measurement of 1,4-dithienylbenzene,1.4-dithienylnaphthalene,9,10-dithiophenanthracene,three molecules with the same length but with different numbers of benzene rings.The results show that at a long distance,the conductivity of 1,4-dithienylbenzene is about 0.461×10^-2 G₀,and that of 1.4-dithienylnaphthalene is about 1.081×10^-2 G₀,9,10-dithienyl anthracene.It is 1.534×10^-2 G₀.At this distance,the charge is mainly transferred through the molecular skeleton,and it is found that the conductance value of this type of molecule increases with the increase in the number of benzene rings.At a closer distance,the three molecules have higher conductance values.It is 4.0×10^-2 G₀.The reason for the higher conductance value is that at this distance,the molecules lie flat on the gold surface,and the charge transport path changes and no longer goes through the molecular skeleton.This type of conductance difference caused by the measurement distance is caused by the difference in the electron transmission path caused by the different contact between the molecule and the gold surface.The conductivity of this molecule can be applied to the construction of molecular switches and other components.（2）Detected by the fix—Junction:the conductance of the two inclusion molecules formed by the inclusion of cucurbituril molecules with the drug molecules oxaliplatin and berberine in deionized water is（5.176±1.82）×10^-6 G₀ and（1.778±0.76）×10^-6 G₀,the conductivity values of the two inclusions are significantly different（about 3 times）.Therefore,the identification and detection of drug molecules in deionized water can be achieved through the difference in molecular conductance.It laid the foundation for the research of drug molecules in the blood.（3）Single-molecule measurement studies have found that there is a competitive coordination between oxaliplatin and berberine for the cucurbituril molecular cavity.Consistent with fluorescence spectroscopy research For the first time,the research on this process has been realized from the perspective of electricity,which provides a new idea for the research of coordination chemistry.