DNA Colorimetric Logic Gates Based Detection Of Heavy Metal Ions And Environmental Hormone In Food

DNA,because of its powerful signal storage capacity,has been applied to the design of molecular logic gates,and is expected to solve the bottleneck of the development of computers.At the same time,DNA logic gates are very popular in biosensors because of the unique molecular recognition and biological property of DNA.In this paper,the biological characteristics of DNA,surface plasmon resonance of gold nanoparticles and aptamers were combined together to construct a series of different functions of DNA logic gates.And the simple basic logic gates were successfully combined together to realize rapid visual detection of mercury ion(Hg²⁺),silver ion?Ag⁺?and bisphenol A?BPA?,bisphenol s?BPS?simultaneously.The main research and conclusions are as follows:1.DNA combinational logic gates was built based on the colorimetric analysis of gold nanoparticles,and was successfully applied to the simultaneous detection of heavy metal ions Hg²⁺,Ag⁺.The protection of part-hybridized DNA on gold nanoparticles was found for the first time.And four basic logic gates?AND?OR?INHIBT1?INHIBIT2?was constructed using the different protective capacities of different structures of DNA on gold nanoparticles.Qualitative and quantitative detections of Hg²⁺and Ag⁺were realized through the parallel combination of basic logic gates.The linear range of Hg²⁺ is from 2?M to 40?M with a detection limit of 2 ?M,and the linear range of Ag⁺ is from 2 ?M to 8 ?M with a detection limit of 0.4 ?M.The successful construction of combinational DNA logic gate and its utilization in the multiple detection of heavy metal ions is of great meaning for the development of DNA molecular computer and its application in analysis.2.The high affinity of BPA aptamer oward BPS was found,an OR logic gate was constructed using BPA,BPS as the two input signals.In this paper,we proposed a simple,economic extraction technology for the separation of BPA and BPS.A more complex series DNA logic gate was built by combining the extraction technology with the OR logic gate,and it was then applied in the fast visual detection of BPA and BPS.The limit of detection?LOD?of BPA and BPS was 1.5 ng/ml and 1.3 ng/m L,respectively.The LOD of the BPA well meet the requirements of standards for residues of BPA set by China and the United States and many other countries.At the same time,this method is successfully applied in the detection of real samples?plastic bottles?,with a recovery of 95.4% to 106.8%,indicating good accuracy and reliabilityof this method.