The Construction Of Molecular Logic Gates And Its Potential Applications

In traditional electronic computers,microprocessors are used to construct basic logic gates circuits that can perform Boolean mathematical logic operations.Similarly,molecular logic gates are the basis for building molecular computers.The construction of logic gates and related molecular devices at the molecular level can imitate the calculation functions of traditional semiconductor logic operations.Especially,logic gates in biosensing,drug delivery,medical diagnosis and smart materials have shown great application potential,which has attracted widespread attention.This research first constructed multiple dual-input and three-input basic logic gates（AND,OR,NOR,INH,IMP,YES,NOT,XOR,NAND）,realized the networked cascade of a series of basic logic gates,and then built a series of compound logic gates（INH-OR,INH-INH,AND-NOR,NOR-OR,NOT-AND-NOR）.Subsequently,employing sequential logic operations,parity checker which can identify even numbers and odd numbers from natural numbers,and molecular keypad-lock security system were established successfully.The respective relevant applications of developed logic systems were explored in early detection of neurodegenerative disease,bacterial detection and inhibition,and wastewater monitoring and treatment.The specific research content is as follows:1.Construction of molecular logic gates based on the interaction of Thioflavin T（Th T）,liposome-loaded Thioflavin T（L-Th T）andα-synuclein and its potential application of early neurodegenerative disease detection.In this chapter,the interaction between Th T,L-Th T andα-synuclein was first explored by using fluorescence analysis.In the absence ofα-synuclein,L-Th T exhibits very low fluorescence intensity.When interacted with aggregatedα-synuclein,the fluorescence intensity of L-Th T liposomes was greatly enhanced.At the same time,the effect of molecular crowding on the acceleration,deceleration,oligomerization or fibrillation ofα-synuclein was monitored through spectral changes.Based on these findings,basic logic gates（AND,OR,IMP,INH,NOR）were systematically constructed.In addition,the three-input multifunctional cascaded logic gates（INH-OR,INH-INH,AND-NOR,NOR-OR and NOT-AND-NOR）were constructed,and a molecular logic wheel were successfully designed too.Finally,a four-input parity checker was established,which can identify erroneous data in the received data by giving a"TRUE"or"FALSE"output.Based on the difference binding affinity ofα-synuclein,this molecular operating system can provide new ideas for the early diagnosis of diseases,such as Alzheimer’s.2.Hepatoprotective Angelica sinensis silver nanoformulation against multidrug resistant bacteria and the integration of a multicomponent logic gate system.Based on the extract of Angelica sinensis,a traditional Chinese medicinal plant,the green route was used to synthesize six silver nanoparticles（AS-Ag NPs）with liver protection,good biocompatibility and antibacterial properties.AS-Ag NPs were systematically characterized by UV-visible spectroscopy,TEM,XRD,FT-IR and GC-MS.Consequently,the antibacterial potential of AS-Ag NPs against Gram-positive,Gram-negative and multi-drug resistant bacteria was explored.Mechanistic studies revealed that nanoparticles can effectively destroy cell membranes,and their antibacterial properties are size-dependent.The AS-Ag NPs were also effective against multidrug-resistant bacteria with low MIC value,and no resistance was observed for up to 12 consecutive cycles.The cytocompatibility and cytoprotective effect of AS-Ag NPs were evaluated against Hep G2 cell lines by MTT assay,which showed that 85%of cells were viable up to 100μg m L^-1 of AS-Ag NPs.Based on the above-mentioned interaction between AS-Ag NP1 and bacteria,basic logic gates（AND,OR,NOR,INH,IMP,YES）,three input logic gates（OR,NOR）and combinational logic gates（INH-OR,INH-YES,INH-INH,AND-NOR,NOT-AND-NOR）have been constructed.This intelligent digital logic system will help to achieve automatic and highly sensitive detection of various bacteria,and provide a theoretical basis for the detection of bacteria in the industrialized system.3.Construction of logic gate based on Ag@PCN-224 and its application in water treatment.In this chapter,Ag@PCN-224 was designed and synthesized using the metal organic framework PCN-224,and previously synthesized AS-Ag NP1 which was systematically characterized by means of TEM,SEM,DLS,XRD,BET and EDX.The porous structure of Ag@PCN-224 enables its good metal ion adsorption capacity;at the same time,nano-silver occupies the center of H₂TCPP,which can be used as a catalytically active site and acted as an antibacterial agent.The experimental results show that Ag@PCN-224 can effectively remove pollutants in wastewater.For example,the hollow structure of Ag@PCN-224 can effectively adsorb Pb²⁺,and the removal rate can reach up to 99.6%.In addition,the antibacterial effect of Ag@PCN-224 on Escherichia coli,Staphylococcus aureus and Candida albicans shows that it has broad-spectrum antibacterial properties which are highly effective.In order to evaluate the reliability and operational performance of the nano system,a set of Boolean logic gates（OR,INH-OR,INH-INH,INH&YES,AND-NOR）and parity checker were designed to demonstrate the application of various logic operators in energy saving water treatment.The research will provide a new method for the development of molecular logic systems in water monitoring and treatment.