Highly Sensitive Detection Of Heavy Metal Ions And Telomerase Activity Based On DNA Nanostructures

Over the past three decades DNA has emerged as an exceptional molecular building block for nanoconstruction due to its predictable conformation and programmable intra-and intermolecular Watson-Crick base-pairing interactions.A variety of convenient design rules and reliable assembly methods have been developed to engineer DNA nanostructures of increasing complexity.The ability to create designer DNA architectures with accurate spatial control has allowed researchers to explore novel applications in many directions,such as directed material assembly,structural biology,biocatalysis,DNA computing,nanorobotics,disease diagnosis,and drug delivery.This Perspective discusses the state of the art in the field of structural DNA nanotechnology and presents some of the challenges and opportunities that exist in DNA-based molecular design and programming.In this paper,There are two works based on the above research background is widely used DNA nanostructures,for mercury ion in the environment and food were detected with high sensitivity,and the target of cancer telomerase were detected in situ,as follows: 1.Highly Sensitive Detection of Mercury Ion Based on T-rich DNA Machine using Portable Glucose MeterMercury ion(Hg2+)has threats to human health and the environment even at a low concentration,thus it is desirable to propose a sensitive and portable method to detect it.In this work,it could realize detection of Hg2+ at low femtomolar concentration.Thymine-thymine(T-T)mismatches oligodeoxyribonucleotides were employed as specific recognition elements for selectively capturing Hg2+ to form hairpin structure and triggering the T-rich DNA machine operation to produce a large amount of product DNA for signal amplification.Product DNA connected capture DNA(Capt-DNA)with DNA-invertase conjugation which catalyzed sucrose into glucose.Thus,the output portable glucose meter(PGM)signals which came from glucose is related with the amount of product DNA,indirectly quantifying the concentration of Hg2+.It is shown that the detection limit of this method is as low as 10-17 M and linear range is 10-6~10-17 M without any complicated instrument.What's more,this novel method could be applied in highly sensitive and selective Hg2+ detection in fish samples.Therefore,owing to the simple operability and portable use of PGM,this method is expected to have a wide application in routine detection the concentration of Hg2+ in environmental water and biologic samples in everyone's home.2.High sensitivity detection of telomerase activity in cancer cells based on G-rich DNA enhanced fluorescence intensity of AgNCsTelomerase plays a vital role in cancer and aging,telomerase activity detection has drawn great attention recently.However,a feasible in situ imaging system for intracellular telomerase is still a challenge.Most of the in situ imaging methods for the detection of telomerase activity are in situ imaging with organic dyes,which are more toxic to cells.In this paper we propose a novel method using G base DNA structure can increase the silver cluster light to in situ detection of telomerase activity,good biological compatibility of silver clusters in the play was very good in situ detection.Using primer chain telomerase(Ts)in the presence of telomerase repeat TTAGGG can generate the characteristic of the formation of a hairpin structure,G base generated so can increase the connection in the chain of silver cluster telomerase primers of light,so as to realize the detection of telomerase activity in situ.In this method,the Ts primer chain is successfully extended by telomerase,and the activity of telomerase is the key to the signal output.Then,through the step of pasting and cell activities can successfully detect the difference of telomerase activity in Hela cells and the size of other types of cancer cells and normal cells between cells,and the realization of quantitative detection of telomerase activity in cells.More importantly,this method can be more intuitive to verify the efficacy of some of the drugs to inhibit telomerase activity.Therefore,the use of telomerase activity detection method for fluorescence enhancement,is of profound significance to further understand and grasp the relationship between telomerase and cancer,but it also helps the development of new inhibitors of telomerase activity,this method also enlarges the application function of molecular fluorescence group has good biocompatibility in situ cell imaging detection in cells.