Preparation Of Molybdenum Diselenide Nanoflowers And Its Anti-biofilm Application Based On Piezoelectric Effect

Single-and few-layer molybdenum diselenide（Mo Se₂）has the piezoelectric effect due to its structural asymmetry,allowing for the conversion from mechanical to electrical energy.Meanwhile,the qualities of transition metal elements give it excellent enzyme-mimic activities.In this thesis,the piezoelectric catalytic of Mo Se₂ is combined with the enzyme-mimic activities for antibacterial and biofilm eradication,and the specific mechanism is discussed.The main work is as follows:（1）One-pot hydrothermal method was used to synthesize Mo Se₂nanoflowers（Mo Se₂ nanoflowers,Mo Se₂ NFs）with nanometer size and abundant single-and few-layer structures.Under the action of ultrasound,Mo Se₂ NFs can exert piezoelectric catalysis to produce cytotoxic reactive oxygen species（ROS）.These ROS achieve excellent killing ability against planktonic Gram-positive and Gram-negative bacteria and even drug-resistant bacteria,laying the foundation for the application of Mo Se₂ NFs piezoelectric catalysis for biofilm eradication.（2）The enzyme-mimic activities of Mo Se₂ NFs were investigated,which possess two enzyme-mimic activities:Glutathione oxidase（GSHOx）and Peroxidase（POD）.They are able to respond to the characteristics of the biofilm microenvironment（BME）and specifically exert enzymatic activities in it.Meanwhile,the piezoelectric effect of Mo Se₂ NFs can also exert an enhancement effect on the above two enzyme-mimic activities.Together,the piezoelectric catalysis and the enhanced enzyme-mimic activities synergistically manifest a strong bacterial killing effect and an efficient biofilm eradication ability.Finally,the high biosafety of this Mo Se₂ NFs and the ultrasonic therapy used were confirmed.