Single Microalgae Detection And Activity Assessment In A Microfluidic Chip

Maritime security is heavily threatened by invasions of exotic species caused by ship ballast water,which carries large quantities of microalgae.Full assessment of influence in different approaches to microalgae activity and development of technology evaluation of microalgae activity in convenience and cost are greatly significant for effective control of ship ballast water and protection of marine environment.Microfluidic chip is adopted in the paper,in which single microalgae cell's capture,single microalgae cell's activity monitoring and single microalgae cell's multi-spectrum detection based on liquid filters.Main content of the paper contains following three parts.1)Design a method of capturing single microalgae cell based on gas-liquid interface,making bubbles effective collide with microalgae cell flowing through capture area through injection pump to adsorb microalgae cell on the gas-liquid interface.Analyze factors on experiment results such as PH of liquid phase,size of micro-channel,temperature,solutes and so on.The results prove the comfort zone of PH of phosphate buffer is between 9.0 and 9.2 in capture of Dunaliella salina,and is between 8.9 to 9.1 in capture of Tetraselmis Chui.The lower depth of the microchannel depth is,the easier capture of microalgae is.In addition,width,temperature environment and liquid phase solutes of microchannel determine the efficiency of capturing single microalgae cell.2)Dynamically monitor the activity of captured single microalgae cell by the laser-induced chlorophyll fluorescence,getting dynamic chart of microalgae activity with changing time of dealing reagent.The results of environment prove that the activity of microalgae cell do not decline steadily,whose weakening is a process of irregular lowering.The treatment effect of microalgae with different reagents can be judged through dynamic chart of microalgae activity.Compared with normal detection,single microalgae cell has obvious advantage.Stress resistance of Dunaliella salina is stronger than that of Tetraselmis Chui in the same effect of reagents.3)Study detection technology of single microalgae cell based on liquid-filter,achieving two kinds of filter liquor with different wavelength.On this basis,detection system of a single microalgae cell is designed consisting power supply module,optical detection module,signal processing module and signal acquisition and processing module and so on,and respectively detect fluorescent particles,chlorophyll fluorescence of microalgae cells as well as dye fluorescence of algae cells verifying the effectiveness of the system.The paper provides new idea and reference for assessment system of deactivation technology of microalgae as well as development and application of detection technology of new microalgae cell in ballast water,which is of great significance for the prevention of pollution from ships.