Abstract:

Hydroxyapatite (HAP) nanoparticles and zinc-doped hydroxyapatite (ZnHAP) nanoparticles with a Zn/ [ Ca + ZnJ molar ratio γof 0 - O. 2 were prepared hy means of sol-gel-supercritical fluid drying. Then , FTIR ,XRD and TEM , XRD were adopted to reveal the effects of zinc doping on the structure , crystal shape and crystallinity of the prepared nanoparticles. Moreover , the hacterial inhihition zone and antihacterial ratio were tested to investigate the antihacterial properties of HAP and ZnHAP nanoparticles to Escherichia coli , Stα'Phylococcus aureus and Lactobαcillus. The results are as follows. The sol-gel-supercritical fluid dηing is an effective method to prepare HAP and ZnHAP nanoparticles; zinc can he partially doped in HAP as the suhstitute of Ca to form ZnHAP; after the doping of zinc , the vihration frequencies of IR honds in ZnHAP increase , the transmittance and the crystallinity decrease with the γvalue increasing , and the morphology of the nanoparticles changes from short rod shape to needle shape; both the HAP nanoparticles and the ZnHAP nanoparticles with a γvalue of less than 0. 04 possess antihacterial properties only in dynamical forcible contact with tested bacteria at a nanoparticles content of 0. 1 glmL; the ZnHAP nanoparticles with a γvalue of more than O. 08 possess an antibacterial ability which increases with γ value at the same content no matter whether it is in static or dynamic contact with the tested bacteria. All of the results indicate that the antibacterial property is improved after the zinc doping.

Key words: sol-gel method, supercritical CO₂, dηing, zinc doping, hydroxyapatite nanoparticle, preparation, antihacterial property