Synergism Variation between Intracellular Glutathione, Phycocyanin and SOD in Microalgae by Carbon Quantum Dot Fluorescence

：Based on the use of CQDs as fluorescent probe and covalent coupling method to detect biological molecules with amino groups, this method was applied to the analysis and detection of metabolism of Microcystis aeruginosa. The metabolic changes of carboxyl biomolecules in Microcystis aeruginosa were analyzed by covalent coupling method, including GSH, phycocyanin and SOD enzyme. The changes of GSH content in Microcystis aeruginosa at different growth stages and the correlation between phycocyanin, SOD and GSH were analyzed from one-dimensional, two-dimensional and three-dimensional fluorescence. The content of phycocyanin and SOD reached the maximum on the 65th day, and GSH was more sensitive to the growth and metabolism of microalgae and began to decrease on the 50th day. GSH plays an important role in reducing the external oxidative damage of microalgae cells at each growth stage of microalgae cells. Among them, GSH synthesis, GSH/GSSG mutual transformation, synthesis of phytochelating peptides (PC), ASA-GSH cycle and metabolism and other physiological activities in Microcystis aeruginosa have interactions, which play a key role in maintaining the antioxidant properties of microalgae and regulating redox-sensitive signal transduction.