Sterilization Capability Comparison Of The Silver Engineered Impregnated Onto Biological Carriers With Two Different Pore Structures

The broad-spectrum bactericidal properties of nano-silver have been confirmed,and the sustained-release properties of silver-loaded nano-silver further enhance the long-term sterilization of nano-silver.The pore structure of the carrier has a template effect that controls the size and morphology of the nanosilver particles.Whether or not the nano-silver supported by different pore structures is closely related to its bactericidal performance is a problem worth studying.In this paper,the siliceous shell and the Artemia shell with different pore structures were used as carriers,and the nano-silver was loaded into the siliceous shell and the Artemia shell by in-situ reduction method to prepare the supported nano-silver composites(Si-shell-Ag,C-shell-Ag).In order to distinguish the template effect of different pore structure carriers on the preparation of nano-silver particles and the similarities and differences of sterilization performance,the scale difference of nano-silver particles is observed,and the slow-release effect of silver and its bactericidal properties are tested.Scanning electron microscopy showed that both carriers have abundant pore structure,but the pore structure size and arrangement are obviously different.Combined with TEM,EDS,and XRD observations,nano-silver is successfully loaded into the pores of the two carriers.However,the size range of the nano silver particles is significantly different.The size of the nano silver particles supported by the siliceous shell is about 10-20 nm,and the size of the nano silver particles supported by the Artemia shell is about 20-30 nm.It is proved that the two carriers have a template effect on the size of the nano silver particles,and different carriers can be used to immobilize the nano silver particles of different sizes.The silver slow-release experiments showed that the two silver-loaded composites had good silver release ability in deionized water and medium.The concentration of silver ions in deionized water was maintained at 8.6 mg/L(Si-shell-Ag)and 2.64 mg/L(C-shell-Ag)after four cycles of sustained release.The sustained release amount of silver ion per unit time in water is 0.12 mg/g·h(Si-shell-Ag)and 0.03 mg/g·h(C-shell-Ag),which proves the silver immobilization and sustained release effect of siliceous shell is better than the Artemia shell.The bactericidal experiments of Si-shell-Ag and C-shell-Ag on Escherichia coli and Staphylococcus aureus showed that Si-shell-Ag and C-shell-Ag inhibited Escherichia coli and Staphylococcus aureus.The effect and inhibition effect on Escherichia coli is superior to Staphylococcus aureus.According to the results of minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC),the MIC values of Si-shell-Ag for both bacterias are between 0.24 and 0.50 g/L,and the MBC values are between 1.06 and 2.00 g/L;C-shell-Ag has a MIC value of between 0.32 and 0.62 g/L for both bacterias,and MBC values are between 1.24 and 2.50 g/L.The results of the bactericidal kinetics showed that 2.0 g/L(minimum bactericidal concentration)of Si-shell-Ag completely sterilized Escherichia coli and Staphylococcus aureus requires 180 min and 300 min,respectively;2.5 g/L(minimum bactericidal concentration)of C-shell-Ag completely sterilized Escherichia coli and Staphylococcus aureus requires 240 min and 360 min,respectively.The results of bactericidal experiments showed that the bactericidal effect of Si-shell-Ag was better than that of C-shell-Ag.It was proved that the nano-silver supported by different pore structures was closely related to its bactericidal performance.The size of nano-silver particles was positively correlated with the pore size of the carrier,affecting the size and slow release rate of nano silver particles.