Study On Nanopore Single-channel Technology To Detect Cyanide Compounds

As heavy metal ions,excessive Cu²⁺will be harm to environment and human healthy.The extreme toxiticy of cyanide in physiology system,as well as the continuing environmental concern caused by its widespread instrutrial use,including metallurgy and leather.Thus,it's imperative to find a simple and fast detection method.In this paper,single-channel technology were used to detect Cu²⁺and CN^-,due to the interaction of triazole and Cu²⁺,the conformation of DNA probes were changed.Meanwhile,owing to high affinity of Cu²⁺and CN^-,Cu²⁺can be dissociated from DNA probes and DNA conformation recovered.With this platform,triplex molecular beacons were used to quatitative detection of microRNA,and simutanleous detection has been accomplished.The main conclusions of this paper are listed as follows:1.A specific nanopore single-channel recording system was developed for detecting Cu²⁺and CN^-.?1?DNA probes contains triazole were obtained through chemical modification.According to the interaction of triazole and Cu²⁺,DNA probes conformation were changed.Through single-channel recording system based on nanopore found that the dwell time were prolonged to 49 ms,and current blockades of DNA which combined with Cu²⁺were increased from 83%to 90%.?2?Because the strong complexation of Cu²⁺and CN^-,the conformation of DNA were recovered.Result in current blockades recovered to 82%,transcolation time were shortened,which were consistent with DNA probes without Cu²⁺.2.A specific nanopore single-channel recording system was developed for detecting microRNA based on triplex-forming molecular beacons.?1?Triplex-forming molecular beacons were constructed by DNA probes and DNA encoding molecules.In the presence of microRNA,DNA probes will combined with microRNA to form duplex structure,then DNA encoding molecules were released.Through detecting the current signal of DNA encoding molecules,microRNA were quantified.?2?Five types of DNA triplex structure were designed,screening experiments selected DNA11 and DNA3 to construct triplex structure based on the its stability and frequency of signature events.Through single-channel recording system,the quanitative detection of micro-155 and let-7a were stuied.The detection range of micro-155 were between 5 pM and 100 nM.?3?Selectivity experiments for detection of let-7a,let-7b and let-7c showed that,the frequency of full matched structure DNA8-let 7c were 6.7,one nucleotide mismatched structure DNA6-let 7c declined to 0.9,two mismatched DNA8-let 7a declined to 0.5.Which means that this method can be used to identity single nucleotide difference and applied to the early diagnosis of lung cancer.?4?Through synthesized three types of DNA encoding molecules which given different signature events,simultaneous detection of microRNA from the same family let-7a,let-7b,let-7c were studied.Simultaneous detection frequency of let-7a,let-7b,let-7c events were 4,3.3,4.3 separately.While single detection results were 4.1,3,3.6,which were closely to simultaneous detection.The results showed that the high recognition rate towards complex components and the potential for detecting human serum samples.