Quantitation Trace Cadmium In Single Cells By Graphite Furnace Atomic Absorption Spectrometry

As the basic unit of life activities,cells are the basis of life,the place where the life body stores nutrients and the main body of metabolism,the judgment basis of life and the unit of life body material exchange,and it has the ability to store life’s genetic material.Establishing an accurate,high-sensitivity and rapid analysis method to detect the content of metal ions in cells is a key step to understand the beha vior of cell populations.However,the traditional analysis method is based on the determination of the metal content in a large population of cells,even if it is the same type of cells,there is cellular heterogeneity among them.Therefore,traditional analysis methods will conceal some differences between cells,and the development of single-cell analysis is particularly important.Therefore,this article first established an analytical method for directly measuring the metal content in the cell population,and then designed a single-cell capture microfluidic chip to capture the cells,and finally the captured cells were directly detected by the above method to obtain the metal ions in the single cell.The first chapter briefly introduced the sources and hazards of cadmium,intracellular metal detection methods,and single cell separation and analysis.The second chapter of this article introduces cadmium-incubated liver cancer cells(HepG2)as the research object.The types of matrix modifiers,cell number density,and graphite furnace atomic absorption spectrometer conditions and other related parameters are studied and discussed.On this basis,graphite is established.Furnace atomic absorption spectroscopy is a method for directly quantifying the cadmium content in cells.The lowest detection limit of this analytical method is 1.8 ng/L,and the relative standard deviation is 0.06%(n=9),which can be used to directly determine the cadmium in hundreds of cells(about 400).It can be used to directly determine cadmium in hundreds of cells(about 400);this method can also be used to directly determine cadmium in human whole blood samples.The blood sample volume is only 10 microliters(about 107 blood cells).The method of adding the standard recovery rate verifies the accuracy of the analytical method,and the recovery rate of this method is between 90%and 107%.The method directly measures the metal ions in the cells,is simple and convenient to operate,and has low energy consumption.Chapter 3 of this article introduces the capture and release of single cells by a microfluidic chip designed according to the influence of fluid mechanics and cell size.Through the simulation of COMSOL software and experiments using the HepG2 cell model,it is found that the microfluidic chip can achieve efficient capture and release of single cells according to the expected hydrodynamic behavior.Chapter 4 of this article introduces the use of self-designed single-cell samplers to capture single cells and directly use them in graphite furnace atomic absorption spectrometry to quantitatively analyze cadmium in cadmium-incubated liver cancer cells.The cadmium content in 70 single HepG2 cells was measured in parallel,and the study found that the Cd content in a single cell was between 20 and 1500 fg.The metal content of single cells measured by this method is in good agreement with the content of single cells after digestion.The simple operation of this method opens up a new method for single cell analysis,which is conducive to better study of single cells behavior.