Study On Atomic Force Acoustic Microscopy For Biological Cells

Cell is the basic unit of living organisms.It plays an important role in the physiological activities such as the metabolism,the sensing and the information transmission.There are many types of cells in a human body.Every cell has the unique size,shape,structure and function.The characteristics will change when the cell is pathological.Study on the characteristics of different types of cells such as structures,properties and functions on the nano scale is helpful for understanding the rule of life,the differences of cells and the mechanism of lesion.It is significant for revealing the mysteries of life and researching the early prevention of illness.With the development of nano science and technology,it is possible to detect the subsurface structures and physiological activities of biological cells.The traditional three-dimensional imaging techniques based on the principles of optics and acoustics can detect the subsurface structures.Nevertheless,the resolution is limited due to the diffraction resolution limit.The atomic force microscope(AFM)can measure the surface features of the sample with nano resolution.However,the subsurface structures of the sample cannot be measured.The atomic force acoustic microscope(AFAM),which combines the advantage of three-dimensional imaging and the AFM,can detect subsurface structures of the sample as well as the nanoscale analysis.It has been a useful tool for the study of biological samples.In this thesis,AFAM images of cells were obtained after the different samples including the floppy disk with the magnetic domain structure,disc films and Su-8 films.This method provides an effective and low-cost way for the determination of different phases of epoxy cross-linking process in nanostructured compounds,for the non-destructive testing of subsurface defects,and for the evaluation of the quality of patterned structures.Imaging analysis of biological cells consisted of two parts.The first part was that HL7702 cells and SMMC7721 cells were cured for different time durations and AFM and AFAM images of cells were obtained,respectively.The second part was that the imaging of living cells and the analysis of their characteristics in culture.The traditional AFM surface topography imaging and AFAM imaging of samples were compared.The results showed the advantages of the AFAM and the physiological characteristics of biological cells were analyzed from two aspects of the surface topography and internal structure.The application of AFAM in the study of biological cells can better combine nano detection technology with human health.This work will provide the theoretical basis and experimental basis for the prevention,diagnosis and treatment of diseases.