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Study On Electrochemical Optical Fiber Plasman Resonance Sensor For Heavy Metal Ion Detection

Posted on:2020-04-30Degree:MasterType:Thesis
Country:ChinaCandidate:Y SiFull Text:PDF
GTID:2518306212978689Subject:Optical communication and optical sensing
Abstract/Summary:PDF Full Text Request
At this stage,with the continuous development of society,the negative impact of people on the highly developed industry is not expected to be sufficient,and prevention is unfavorable.It has led to three major global crises:resource shortage,environmental pollution,and ecological damage.Environmental pollution refers to natural or man-made damage,adding a substance to the environment and exceeding the self-purification ability of the environment to cause harm.Due to human factors,the composition or state of the environment changes,and the environmental quality declines.This disrupts and destroys the normal production and living conditions of ecosystems and humans.Heavy metals are highly toxic,low in concentration,non-biodegradable,and generally distributed,posing significant hazards to human and animal health and the environment.For example,when heavy metal ions dissolved in water enter the biosphere and are taken into the organism,they may be very detrimental to human health.Therefore,rapid and accurate detection of metal ions has become an important issue.At present,monitoring methods for heavy metal ions in water mainly include spectroscopy,chromatography and electrochemical analysis.Among them,spectroscopy and chromatography steps are cumbersome,time consuming and expensive to detect.Anodic Stripping Voltammetry(ASV),which is used in electrochemical analysis methods,is very efficient compared to it,so it is currently the most widely used method.However,electrochemical methods suffer from unresolved electrochemical noise and unavoidable environmental interference,which can affect the electrode measurement process,thereby greatly limiting their Limit of Detection(LOD).When Surface Plasmon Resonance(SPR)is combined with electrochemistry,Electrochemical Surface Plasmon Resonance(EC-SPR)technology provides simultaneous detection of current,voltage and ion electrochemical on the electrode.In this part,many efforts have been made to combine long range SPR and local SPR with electrochemical to produce a dual detection system for detecting heavy metal ions.However,the large prism configuration required for these spectral analysis techniques is very inconvenient and may limit difficult to reach space and monitoring in remote environments.Based on the above research background,this paper has carried out the following research work:(1)A novel electrochemical surface Plasmon resonance(EC-SPR)fiber sensor is proposed:the sensor comprises a tilted fiber Bragg grating imprinted in a commercial single-mode fiber and coated with a nano scale gold film for high-efficiency SPR excitation.The gold-coated fiber acts as the working electrode,and the surface energy produces an optical plasmon resonance wave.,by taking derivative of the SPR amplitude change,we can clearly identify the peak stripping potential of the detected ions and therefore realize specific ion identification,and as the concentration of heavy metal ions becomes higher,the magnitude of the change in the surface plasmon resonance response intensity also increases.Fiber optic sensors have the dual function of anodic stripping voltammetry and SPR optical sensing.Therefore,it is possible to simultaneously acquire important reference information such as optical SPR and current,and bring comprehensive and convenient information for analysis work.(2)Based on the self-designed EC-SPR fiber sensor,the ultra-sensitive detection of typical heavy metal ions Pb2+is realized,it also can specific detect heavy metal ion mixed solution,and the stable and reproducible correlation between the heavy metal ion deposition-stripping process and the SPR signal change is obtained,accurate detection of ultra-low detection limits for Pb2+ions 10-10 M,and realize linear response output in the large dynamic detection range(10-10?10-5 M).The developed EC-SPR fiber optic sensor has the advantages of compact size,flexible shape and remote operation capability,providing detection means for various difficult to implant small spaces and large-scale remote environment monitoring.
Keywords/Search Tags:optical fiber sensor, surface plasmon resonance, heavy metal ion detection, differential pulse anodic stripping voltammetry
PDF Full Text Request
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