Application Of Hybridization Chain Reaction In Backpack Problems And Logical Operations

Hybridization chain reaction stands out in many biochemical reactions because of its simple operation and significant amplification effect.It has been used as a tool to amplify signals in many studies.In mathematical research,0-1 knapsack problem is the most representative subproblem in combinatorial optimization problem.It has important applications in the fields of factory location,production scheduling,allocation problem and reliability problem.In the aspect of electronic computer,logic gate is not only the basis of constructing electronic computer,but also the basic unit of digital logic circuit.There are relevant DNA computing algorithms in the field of 0-1 knapsack problem and logic gate,and it has always been the research goal of scholars to spend less cost and reap greater benefits.The focus of this thesis is to study the amplification of hybridization chain reaction in the solution of 0-1 knapsack problem and logic gate problem.(1)In the construction idea of the quasi closed-loop double stranded DNA calculation model for solving the 0-1 knapsack problem,based on the cyclic hybridization amplification of hairpin DNA and the stability of ring structure,a kind of closed-loop double stranded DNA model is designed to solve the 0-1 knapsack problem.Firstly,through base complementary pairing,the initiating DNA is fixed on the single strand of circular DNA to form a closed-loop like double stranded DNA.Then,with the help of hybridization chain reaction technology,the hairpin DNA bound with biotin is combined to the quasi closed-loop structure,and then biotin is used to attract streptavidin,and the biological bar code bound with streptavidin is also combined to the quasi closed-loop structure.Finally,the Raman signal on the closed-loop structure is detected by surface enhanced Raman scattering technology to complete the screening of feasible solutions.(2)In the construction of signal amplified molecular logic AND gate based on DNA triple strand structure,oligonucleotides formed by promoter chain and triplex are used as input signals.When both input signals exist,the substrate in the solution first hybridizes with the promoter chain;then,the product obtained from the hybridization chain reaction forms an oligonucleotide with a triplex to form a triplex structure;finally,berberine will be adsorbed to the three-stranded structure to excite the high background fluorescence and use it as the output signal.Similarly,the logic OR gate model is constructed with the starting chain as the input signal and the high background fluorescence as the output signal.To sum up,the advantages of signal amplification and simple operation of hybridization chain reaction have been fully applied in solving 0-1 knapsack problem and logic gate problem,and positive feedback has been obtained,which provides ideas for solving 0-1 knapsack problem and logic gate problem.Figure [22] Table [6] Reference [49]...