| Bioinformatics is a discipline that use information(computer)science and technology to analyze and interpret biological molecules such as nucleic acids and proteins with the help of mathematics,biology,and chemistry.DNA computing is an emerging computing technology,and use the reaction of DNA to solve large-scale computing problems.DNA logic operation platform overcome the shortcomings of traditional silicon material computer components,such as large size,and strong computing power,flexible design has become the focus of attention.The emergence of biosensors apply DNA computing to the detection of various targets in practice.It has many advantages such as low cost,fast response,and detect targets with high sensitivity and selectivity.Miniature biosensors have become promising detection methods in various fields such as disease diagnosis,biological analysis,environmental monitoring and food control.In recent years,new nanomaterials have huge impact on the development of biosensing technology due to their special physical and chemical characteristics,and they have become indispensable part of sensors.Graphene oxide(GO),which is an oxide of graphene,has good water dispersibility,high mechanical strength,and easy to prepare in large quantities.It becomes the most promising candidate for building biosensors.At the same time,because of unique adsorption capacity,it is used to regulate the signal outputs of DNA logic devices.In addition,G-quadruplex,as a special nucleic acid structure,has structural polymorphisms and specific biological functions.It is worth noting that after reacting with the N-methyl-mesoporphyrin ?(NMM),a significantly enhanced fluorescent signal generated,thus taking on the role of signal reporter in the fields of DNA computing and biosensing.Based on graphene oxide and G-quadruplex,fluorescence aptasensor and DNA logic operation platform for thrombin detection were constructed in this paper.The specific research work is as follows:An enzyme-and label-free aptamer-based assay is described for the determination of thrombin.A DNA strand(S)consisting of two parts was designed,where the fifirst(Sa)is the thrombin-binding aptamer and the second(Se)is a G-quadruplex.In the absence of thrombin,Sa is readily adsorbed by graphene oxide(GO),which has a preference for ss-DNA rather than for ds-DNA.Upon the addition of NMM,its fluorescence(with excitation/emission at 399/610 nm)is quenched by GO.In contrast,in the presence of thrombin,the aptamer will bind thrombin,and thus,be separated from GO.As a result,fluorescence will be enhanced.The increase is linear in the 0.37 nM to 50 ?M thrombin concentration range,and the detection limit is 0.37 nM.The method is highly selective over other proteins,cost-effffective,and simple.In this perception,it represents a universal detection scheme that may be applied to other targets according to the proper choice of the aptamer sequence and formation of a suitable aptamer-target pair.In the fields of biologicalcomputing and biomolecular,we can find that more molecular universal logic platforms with different functions,which perform various tasks.Graphene oxide(GO)is a special new nanomaterial,which has attracted more attention in material science and biosensors due to its excellent property and great quenching ability.As a special DNA structure with excellent binding activity,G-quadruplex has became the focus in biomedicine and biochemistry.In this paper,enzyme-free and universal logic device based on G-quadruplex and GO was constructed.According to the quenching ability of GO to the TAMRA(fluorophore,Carboxytetramethylrhodamine)and the enhancement of fluorescence intensity produced by the specific binding of G-quadruplex to the NMM,advanced logic gates(half adder and half subtractor)were proposed and verified by a series of biological experiments.This proved the feasibility of the proposed platform.The proposed universal platform has great prospective applications in the field of bio-imaging as well as disease diagnosis. |
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