铒掺杂羟基磷灰石的荧光及其生物矿化性能

Fluorescence and Biomineralization Ability of Erbium-Doped Hydroxyapatite

通过共沉淀法制备铒掺杂羟基磷灰石(Er-HAP)颗粒,应用Materials Studio模拟与X射线衍射、扫描电镜-能量色散谱、X射线光电子能谱和荧光光谱分析对其晶体结构、表面化学成分及其荧光性能进行表征。结果表明,离子半径稍小的Er^(3+)会竞争性占据HAP晶格中一个Ca^(2+)位点,在340 nm波长激发下,Er-HAP颗粒能在419 nm(紫色)、458 nm(蓝色)、501 nm(绿色)和535nm(绿色)处发出很强的特征荧光,光致发光显示的4个发光带相应归属于~4F_(3/2)→~4I_(15/2)、~4F_(5/2)→~4I_(15/2)、~4F_(7/2)→~4I_(15/2)和~4S_(3/2)→~4I_(15/2)过渡态。相比掺杂量(物质的量分数)1%的Er-HAP,掺杂量9%的Er-HAP颗粒表面矿化速度和成骨性能均明显下降,即当Er掺杂量在约1%时,其Er-HAP生物矿化能力相对较强。

Erbium-doped hydroxyapatite (Er-HAP) particles were prepared by the co-precipitation method.The crystal structure,surface chemical composition,and fluorescent properties of Er-HAP particles were characterized by the methods of X-ray diffraction combined with Materials Studio,scanning electron microscopy-energy dispersive spectroscopy,X-ray photoelectron spectroscopy,and fluorescence spectroscopy.The results showed that Er^(3+)can competitively substitute for a Ca^(2+)site in the crystal lattice.Under the excitation of a 340 nm light source,Er-HAP particles emitted significant fluorescence at around 419 nm (purple),458 nm (blue),501 nm (green),and 535 nm(green),respectively.The four corresponding luminescence bands are attributed to~4F_(3/2)→~4I_(15/2),~4F_(5/2)→~4I_(15/2),~4F_(7/2)→~4I_(15/2),and~4S_(3/2)→~4I_(15/2)transition states,respectively.Further,we evaluated the biomineralization ability by analyzing the formation of an interfacial layer after Er-HAP particles were immersed in simulated body fluid.When the dopant content (molar fraction) of Er^(3+)was 1%,it was observed that Er-HAP particles could form the mineralized layer with plate-like structures,and Er^(3+)incorporation affected the biomineralization ability,whereas the biomineralization rate and osteogenic performance significantly decreased with the increasing of the dopant content of Er^(3+).Therefore,the stronger biomineralization ability of Er-HAP particles might be exhibited while the Er dopant content was about 1%.