Study On Microparticle Detection Technology Of Multi-wavelength Lensless Holography

Microparticles are widely found in the field of natural environment and medicine,marine microplastics seriously destroy the ecological balance of the ocean and human life and health,harmful microorganisms carried in ship ballast water seriously destroy the marine environment,pose a threat to the life of other organisms in the ocean,cancer cells seriously endanger human life and health,and the detection of cancer cells is of great significance in the field of medicine,so the detection of microparticles is of great importance to life science,nature and medicine.Because the traditional detection equipment is large in size,expensive and complexin operation,it is very important to develop portable,fast and simple microparticle detection equipment.In this paper,a microparticle detection method and system based on three-wavelength lensless holographic imaging are proposed.The imaging principle of this system is that the partially coherent light is irradiated to the microparticle solution through the micropores,the scattered light on the surface of the microparticle and the transmitted light of the solution are the object light and the reference light,respectively,the object light and the reference light interfere with each other to form a holographic pattern.Using the holographic pattern of microparticles excited by three wavelengths:red,green and blue,the two-dimensional and three-dimensional reconstruction images of microparticles are obtained by reproducing image reconstruction algorithm,three-wavelength iterative algorithm and three-dimensional reconstruction algorithm which weaken conjugate image.The system is mainly composed of light source module,light propagation module,microfluidic chip module,image acquisition module and image processing module.In this paper,three typical microparticle samples were selected:polystyrene particles,microalgae cells,cancer cells.The species of polystyrene particles were detected by the length,width of the two-dimensional reconstructed images of polystyrene particles and height of the three-dimensional reconstructed images of polystyrene particles;the species of microalgae cells were detected by the length,width of the two-dimensional reconstructed images of microalgae cells and height of the three-dimensional reconstructed images of microalgae cells;the activity of microalgae cells was determined by the height information of the three-dimensional reconstructed images of microalgae cells;and the species of cancer cells were detected by the length and width of the two-dimensional reconstructed images of cancer cells;the volume of this system is 5×5×10 cm3,and the measurable cell concentration is as high as 107 per mL.The three-wavelength lensless holographic imaging microparticle detection system designed in this paper has the advantages of simple portability and high concentration of measurable samples.