Research On Pb²⁺ Detection Technology Of TFBG-SPR Based On DNAzyme

Heavy metal ion detection technology has great significance in current food safety,environmental management,industrial pollution and other aspects.At the same time,as the rapid development of transformation science and technology,the heavy metal ion detection is not required in the field of pollution seriously,but also in the fields of high-end medical equipment manufacturing,new biomedical research and development,high-end chip manufacturing,new energy technology development,aerospace and marine engineering.It has become an indispensable means of detection.These new areas also put forward new demands for heavy metal ion detection technologies,such as ultra-trace detection limits,in vivo detection,and remote real-time monitoring.The traditional methods of detecting heavy metal ions are spectrometry,mass spectrometry,and electrochemical methods.These methods are complicated to operate,needing expensive instruments,and not suitable for on-site real-time online detection.The SPR sensor has the advantages of high detection sensitivity,no need for purification and labeling of the sample,and real-time monitoring.On the other hand,with the help of biological aptamers such as nucleic acids,proteins,DNA,and RNA,the biochemical sensors for heavy metal ions have good sensitivity and selectivity.They are the main research directions of heavy metal ion detection currently.The tilted fiber grating sensor based on surface plasmon resonance has made some progress in the field of biochemical sensing due to its advantages of high sensitivity,no need for labeling and online detection.Therefore,this paper proposes to design a tilted fiber grating lead ion sensor based on the DNAzyme system in response to the demand for heavy metal ion detection combined with the advantages of fiber grating SPR sensing technology.The main work of this article is introduced as follows:Firstly,this paper introduces the development history,main types and basic principles of SPR sensors,and introduces in detail the optical fiber SPR sensors.Lately,the application field,development process and future application prospects of heavy metal ion detection were introduced,and the work of biochemical sensing was mainly introduced.This paper combined SPR sensing technology with DNAzyme detection system to study lead ion detection.Secondly,by summarizing the DNAzyme ion detection system and the SPR ion detection system,this paper designed a disposable optical fiber SPR lead ion sensor based on DNAzyme,and studied its feasibility and performance for the detection of lead ion.This paper introduced the writing method and coating method of the inclined grating fiber used in the experiment,as well as the preparation method and characterization of the gold nanoparticles.And then,it summarized specific functional steps of this sensor.And then,the feasibility of the sensor for detecting trace concentration of lead ions was verified,and the diameter conditions of gold nanoparticles were optimized.Through the detection of samples with different lead ion concentrations,the linear detection range of the sensor is calculated to be 10-¹⁴-10^-6M,the detection limit is 10^-15M,which is more than three orders of magnitude lower than the traditional detection method.It is also very competitive among biochemical sensors.This paper also detected the concentration of lead ions in actual tap water samples.Finally,in order to repeat the experiment,this paper changed the structure of the functionalized group and designed a folded optical fiber SPR lead ion sensor based on DNAzyme.This paper summarized the action mechanism and specific functional steps of this sensor,and then verified the feasibility of this sensor for the detection of trace concentrations of lead ions by monitoring and surface characterization of the gold nanoparticles binding process.The diameter conditions were optimized,and samples with different lead ion concentrations were tested.It also compared this sensor with the disposable structure one.