Facile Synthesis of Superparamagnetic Fluorescent ... AWS
Facile Synthesis of Superparamagnetic Fluorescent Fe3O4/ZnS Hollow Nanospheres Zhenxuan Wang, Limin Wu,* Min Chen, Shuxue Zhou
Supporting Information Experimental Section Materials: Triton X-100, HeLa cell line, polyvinypyrrolidone (PVP, Mw 40,000), 3-(4,5dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide (MTT), phosphate-buffered saline (PBS), zinc acetylacetonate (ZA), doxorubicin (DOX) and thioacetamide were purchased from Aldrich. Serum-free media (SFM) was supplied by Gibco Life Technologies Co., Ltd (Karlsruhe, Germany). Ammonium ferrous sulfate, ammonium citrate, ammonium nitrate, isopropanol and glycol were obtained from Sinopharm Chemical Reagent Co., Ltd. Ammonia-ammonia chloride buffer solution (pH = 9.1, mixture of equal volume of ammonia solution (0.1 M) and ammonia chloride solution (0.2 M)) and deionized water were prepared by ourselves. All chemicals were used as received. Synthesis of FeS particles: 30 mL of thioacetamide aqueous solution (0.1 M) with ammonium ferrous sulfate (0.1 M) and ammonium citrate (0.1 M) were added into a 50 mL flask, and then dropped by 10 mL of ammonia-ammonia chloride buffer solution under stirring. After bubbing this solution with N2 for 30 min, the flask was sealed and placed in a thermostatic water bath at 85 oC for 15 min, and then removed from the water bath and immersed in an ice-water mixture to quench the reaction, followed by continuous stirring for 6 h. The flask was then driven into water bath again to heat at 85 oC for another 6 h. The precipitate was collected by centrifugation and washed with water and ethanol for 3 times, and then redispersed into 30 mL of PVP glycol solution (10.5×10−4 M) for subsequent reaction. S1
Synthesis of Fe3O4/ZnS HNSs: The mixture of the above dispersion, 30 mL of ZA glycol solution (0.21 M) and 0.2 mL of ammonium nitrate aqueous solution (0.13 M) was transferred into a Teflonlined autoclave, sealed, and heated at 150 oC for 10 h. The solid product was obtained by centrifugated and washed with water and ethanol for 3 times, and dried under vacuum at 100 oC for 12h. Cell assay: HeLa cells were allowed to attach for 24 h before treated with Fe3O4/ZnS HNSs. The cells were washed with PBS, followed by replacement of the media containing various concentrations (0, 1, 10, and 50 µM) of Fe3O4/ZnS HNSs. After the cells were incubated for 48 h. the media were removed and replaced with serum-free media. 10 µL of the MTT stock solution (5 mg mL−1) was added to each well and incubated at 37 oC for 4 h. The supernatant was then removed and cells were lysed with 110 µL of the solubilization buffer (10% Triton X-100 and 0.1 N HCl in isopropanol). The absorbance was read at 570 nm in a microplate reader (Bio-Rad model). Adsorption and release of doxorubicin: 5 mg of DOX and 10 mg of Fe3O4/ZnS HNSs were mixed with 4 mL of PBS for 24 h. After the adsorption was completed, the HNSs loaded with DOX were captured by a magnet, and the solution was removed and assessed for the content of DOX for the calculation of DOX loading content. The HNSs were dried in a vacuum oven overnight and suspended into 2 mL of PBS holding in a quartz cell. At a given time, the sample was captured to the bottom using a magnet, and the resultant supernate was monitored by a UV spectrophotometer at 480 nm. After each measurement, the sample was redispersed by shaking. Instrumental analyses: TEM images and SAED were recorded using a Hitachi H-800 microscope. HRTEM and EDX were carried out on the section HNSs with a JEOL 2010 microscope at an acceleration voltage of 200 kV. XRD spectra were taken on a Rigaku D/max-rB diffractometer with Cu Kα radiation. Nitrogen adsorption-desorption was performed using an ASAP 2010 analyzer, and the pore size distribution was calculated by means of Brunauer-Joyer-Halenda (BJH) method. VSM (EG&G Princeton Applied Research Vibrating-Sample Magnetometer Model 155, USA) was used to characterize the magnetic properties. The photoluminescent properties were characterized by a spectroflurometer (RF-5301PC). Rhodamine B/ethanol solution was used as a comparative standard S2
during measurement of fluorescence quantum yield. A microplate reader (Bio-Rad model) was employed to do cytotoxicity readings. References (5f) Jia, C.; Sun, L.; Luo, F.; Han, X.; Heyderman, L. J.; Yan, Z.; Yan, C.; Zheng, K.; Zhang, Z.; Takano, M.; Hayashi, N.; Eltschka, M.; Kläui, M.; Rüdiger, U.; Kasama, T.; Cervera-Gontard, L.; Dunin-Borkowski, R. E.; Tzvetkov, G.; Raabe, J. J. Am. Chen. Soc. 2008, 130, 16968–16977.
Figure S1. (a) TEM image of the Fe3O4/ZnS HNSs. EDX analysis of (b) the shell and (c) the core, corresponding to the circles 1 and 2 in (a), respectively.
Figure S2. The mean outer-diameters and distribution of FeS spheres (0h), and the spheres from different reaction at 150 oC for 2 h, 4 h, 6h, and 10h.
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Figure S3. XRD patterns of FeS particles (top), the as-synthesized HNSs from reaction at 150 oC for 4 h (middle) and for 10 h (bottom).
Figure S4. Resultant half-hollow NSs after 10 h reaction when only half of the typical amount of ZA was introduced into the reaction system
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Figure S5. The as-synthesized Fe3O4/ZnS HNSs show (a) photoluminescence (PL) spectra with a maximum at 431 nm and (b) the afterglow decay behavior monitored at 431 nm after irradiation with a UV lamp (365 nm) for 20 min.
Figure S6. Magnetization versus temperature measured in both the zero field-cooling (ZFC) and the field-cooling (FC) modes for the Fe3O4/ZnS HNSs.
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Figure S7. Comparative morphology (with a magnification of 20×) of HeLa cells (a) before (negative control) and (b) after the HNSs treatment (50 µM) for 48 h. (c) Cytoxicity readings of HeLa cells treated with various HNSs concentrations for 48 h.
Figure S8. Release of DOX from Fe3O4/ZnS HNSs.
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Supporting Information Experimental Section Materials: Triton X-100, HeLa cell line, polyvinypyrrolidone (PVP, Mw 40,000), 3-(4,5dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide (MTT), phosphate-buffered saline (PBS), zinc acetylacetonate (ZA), doxorubicin (DOX) and thioacetamide were purchased from Aldrich. Serum-free media (SFM) was supplied by Gibco Life Technologies Co., Ltd (Karlsruhe, Germany). Ammonium ferrous sulfate, ammonium citrate, ammonium nitrate, isopropanol and glycol were obtained from Sinopharm Chemical Reagent Co., Ltd. Ammonia-ammonia chloride buffer solution (pH = 9.1, mixture of equal volume of ammonia solution (0.1 M) and ammonia chloride solution (0.2 M)) and deionized water were prepared by ourselves. All chemicals were used as received. Synthesis of FeS particles: 30 mL of thioacetamide aqueous solution (0.1 M) with ammonium ferrous sulfate (0.1 M) and ammonium citrate (0.1 M) were added into a 50 mL flask, and then dropped by 10 mL of ammonia-ammonia chloride buffer solution under stirring. After bubbing this solution with N2 for 30 min, the flask was sealed and placed in a thermostatic water bath at 85 oC for 15 min, and then removed from the water bath and immersed in an ice-water mixture to quench the reaction, followed by continuous stirring for 6 h. The flask was then driven into water bath again to heat at 85 oC for another 6 h. The precipitate was collected by centrifugation and washed with water and ethanol for 3 times, and then redispersed into 30 mL of PVP glycol solution (10.5×10−4 M) for subsequent reaction. S1
Synthesis of Fe3O4/ZnS HNSs: The mixture of the above dispersion, 30 mL of ZA glycol solution (0.21 M) and 0.2 mL of ammonium nitrate aqueous solution (0.13 M) was transferred into a Teflonlined autoclave, sealed, and heated at 150 oC for 10 h. The solid product was obtained by centrifugated and washed with water and ethanol for 3 times, and dried under vacuum at 100 oC for 12h. Cell assay: HeLa cells were allowed to attach for 24 h before treated with Fe3O4/ZnS HNSs. The cells were washed with PBS, followed by replacement of the media containing various concentrations (0, 1, 10, and 50 µM) of Fe3O4/ZnS HNSs. After the cells were incubated for 48 h. the media were removed and replaced with serum-free media. 10 µL of the MTT stock solution (5 mg mL−1) was added to each well and incubated at 37 oC for 4 h. The supernatant was then removed and cells were lysed with 110 µL of the solubilization buffer (10% Triton X-100 and 0.1 N HCl in isopropanol). The absorbance was read at 570 nm in a microplate reader (Bio-Rad model). Adsorption and release of doxorubicin: 5 mg of DOX and 10 mg of Fe3O4/ZnS HNSs were mixed with 4 mL of PBS for 24 h. After the adsorption was completed, the HNSs loaded with DOX were captured by a magnet, and the solution was removed and assessed for the content of DOX for the calculation of DOX loading content. The HNSs were dried in a vacuum oven overnight and suspended into 2 mL of PBS holding in a quartz cell. At a given time, the sample was captured to the bottom using a magnet, and the resultant supernate was monitored by a UV spectrophotometer at 480 nm. After each measurement, the sample was redispersed by shaking. Instrumental analyses: TEM images and SAED were recorded using a Hitachi H-800 microscope. HRTEM and EDX were carried out on the section HNSs with a JEOL 2010 microscope at an acceleration voltage of 200 kV. XRD spectra were taken on a Rigaku D/max-rB diffractometer with Cu Kα radiation. Nitrogen adsorption-desorption was performed using an ASAP 2010 analyzer, and the pore size distribution was calculated by means of Brunauer-Joyer-Halenda (BJH) method. VSM (EG&G Princeton Applied Research Vibrating-Sample Magnetometer Model 155, USA) was used to characterize the magnetic properties. The photoluminescent properties were characterized by a spectroflurometer (RF-5301PC). Rhodamine B/ethanol solution was used as a comparative standard S2
during measurement of fluorescence quantum yield. A microplate reader (Bio-Rad model) was employed to do cytotoxicity readings. References (5f) Jia, C.; Sun, L.; Luo, F.; Han, X.; Heyderman, L. J.; Yan, Z.; Yan, C.; Zheng, K.; Zhang, Z.; Takano, M.; Hayashi, N.; Eltschka, M.; Kläui, M.; Rüdiger, U.; Kasama, T.; Cervera-Gontard, L.; Dunin-Borkowski, R. E.; Tzvetkov, G.; Raabe, J. J. Am. Chen. Soc. 2008, 130, 16968–16977.
Figure S1. (a) TEM image of the Fe3O4/ZnS HNSs. EDX analysis of (b) the shell and (c) the core, corresponding to the circles 1 and 2 in (a), respectively.
Figure S2. The mean outer-diameters and distribution of FeS spheres (0h), and the spheres from different reaction at 150 oC for 2 h, 4 h, 6h, and 10h.
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Figure S3. XRD patterns of FeS particles (top), the as-synthesized HNSs from reaction at 150 oC for 4 h (middle) and for 10 h (bottom).
Figure S4. Resultant half-hollow NSs after 10 h reaction when only half of the typical amount of ZA was introduced into the reaction system
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Figure S5. The as-synthesized Fe3O4/ZnS HNSs show (a) photoluminescence (PL) spectra with a maximum at 431 nm and (b) the afterglow decay behavior monitored at 431 nm after irradiation with a UV lamp (365 nm) for 20 min.
Figure S6. Magnetization versus temperature measured in both the zero field-cooling (ZFC) and the field-cooling (FC) modes for the Fe3O4/ZnS HNSs.
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Figure S7. Comparative morphology (with a magnification of 20×) of HeLa cells (a) before (negative control) and (b) after the HNSs treatment (50 µM) for 48 h. (c) Cytoxicity readings of HeLa cells treated with various HNSs concentrations for 48 h.
Figure S8. Release of DOX from Fe3O4/ZnS HNSs.
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