Highly Uniform 伪-NaYF4:Yb/Er Hollow Microspheres and Their Application as Drug Carrier

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• 作者：Yunhua Han ; Shili Gai ; Ping鈥檃n Ma ; Liuzhen Wang ; Milin Zhang ; Shaohua Huang ; Piaoping Yang
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：August 19, 2013
• 年：2013
• 卷：52
• 期：16
• 页码：9184-9191
• 全文大小：400K
• 年卷期：v.52,no.16(August 19, 2013)
• ISSN：1520-510X

文摘

Highly uniform 伪-NaYF₄:Yb/Er hollow microspheres have been successfully prepared via a simple two-step route. First, the core鈥搒hell structured MF@Y(OH)CO₃:Yb/Er precursor was fabricated by a urea-based homogeneous precipitation method using colloidal melamine formaldehyde (MF) microspheres as template. Then the Y(OH)CO₃:Yb/Er precursor was transformed into hollow NaYF₄:Yb/Er (伪 and 尾 mixed phase) by a subsequent solvothermal method, and MF microspheres were dissolved in the solvent simultaneously. The mixed phase of NaYF₄:Yb/Er was transferred into pure 伪-NaYF₄:Yb/Er by calcination. The as-prepared hollow microspheres were well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectrum (EDS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and upconversion (UC) luminescence spectroscopy. It is found that the template can be removed without additional calcination or etching process. 伪-NaYF₄:Yb/Er hollow microspheres exhibit bright upconversion (UC) luminescence under 980 nm laser diode (LD) excitation. Furthermore, the hollow microspheres show sustained and pH-dependent doxorubicin hydrochloride (DOX) release properties; in particular, the emission intensity increases with the release amount of drug, making the release process able to be tracked or monitored by the change of the emission intensity, which demonstrates the high potential of this kind of hollow fluorescent material in drug delivery fields.