Study On Elemental Imaging Technology Of Biological Tissues By Excimer Laser Induced Breakdown Spectroscopy

Metal elements play an important role in biological tissues.By analyzing the distribution of metal elements in biological tissues,we can not only obtain the physiological status of tissues,but also understand the external environment of living thing.The elemental imaging technology based on Laser induced Breakdown Spectroscopy(LIBS)is a progress that the laser ablation the samples' surface and produce the plasma which near the surface.Then,the spectrometer detecte spectral information,and by means of scanning lattice acquisition target spectrum of each point in the area of information,draw the corresponding spectral imaging pseudo color map information.Due to its advantages of fast detection,simple sample preparation,in situ detection and high sensitivity,it has been widely used in biomedicine,botany,geology and other fields.Moreover,this technique has the characteristics of fast detection speed,multi-element analysis and high spatial resolution,and can be used to detect the element distribution on the surface of biological tissue and other samples.Excimer laser which output in ultraviolet and deep ultraviolet band has high photon energy,low thermal effect,better distribution of spot,which can be adapted to the biological tissue surface element analysis.In order to meet the requirements of optical spot uniformity,spatial resolution and detection speed for biological tissue element-imaging,firstly,an element-imaging system based on 193 nm excimer LIBS was built,including laser,collimating beam broadening system,microscopic imaging lens,spectrometer,displacement table and other devices in this project.And we designed a set of automatic operation software based on LabVIEW,including Actor Framework,interaction module,spectrometer module,electric displacement module and data processing module;Then the delay characteristics,plasma temperature and electron density of aligned molecular LIBS technology are studied.Finally,the biological samples such as shell and corn were prepared,and the surface of the samples were scanned automatically and analyzed by elemental imaging with the above system.Through the above experiments,firstly,the system of devices and control software which was built meet the the requirements of spatial resolution and detection speed of biological tissue element-imaging.Secondly,the feature of excimer LIBS technology in the elemental imaging of biological tissues were understood.Finally,the distribution diagram of sample elements is obtained and analyzed through the research of shell and corn.Elemental imaging technology based on excimer LIBS has the characteristics of fast,convenient and high resolution,and has a good application prospect in biology.