Role of Fe doping in tuning the band gap of TiO2 for the photo-oxidation-induced cytotoxicity paradigm.
Role of Fe doping in tuning the band gap of TiO2 for the photo-oxidation-induced cytotoxicity paradigm.
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DOI：
10.1021/ja202836s
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发表时间：
2011-07-27
影响因子：
15
通讯作者：
Maedler, Lutz
中科院分区：
文献类型：
--
作者：
George, Saji;Pokhrel, Suman;Ji, Zhaoxia;Henderson, Bryana L.;Xia, Tian;Li, LinJiang;Zink, Jeffrey I.;Nel, Andre E.;Maedler, Lutz
紫外光诱导的电子-空穴（e-/h+）对的产生和自由基的产生在基于TiO 2的纳米颗粒是生物损伤的主要概念范例。然而，到目前为止，由于紫外线的高能量对生物系统具有固有的高毒性，这种假设一直难以通过实验验证。在这里，一个通用的火焰喷雾热解（FSP）合成工艺已被用来合成铁掺杂（0-10重量%）的TiO 2纳米粒子库。已使用近可见光暴露测试这些颗粒的光活化介导的细胞毒性。尽管Fe分布均匀（通过XRD、HRTEM、SAED、EFTEM和EELS证明），但随着Fe负载量的增加，TiO 2带隙能量的降低保持了纳米颗粒的晶体结构。光化学研究表明，带隙能量的微调成正比的Fe含量。Fe掺杂的TiO 2的光氧化能力被发现增加在近可见光曝光。使用巨噬细胞系来评估细胞毒性和ROS产生，显示出与带隙能量降低平行的氧化剂损伤和细胞死亡增加。这些发现表明了带隙能量在细胞对TiO 2纳米颗粒的光毒性反应中的重要性，并反映了这种材料在高强度光暴露期间对人类和环境产生不利影响的潜力。
UV-Light induced electron-hole (e−/h+) pair generation and free radical production in TiO2 based nanoparticles is a major conceptual paradigm for biological injury. However, to date, this hypothesis has been difficult to experimentally verify due to the high energy of UV light that is intrinsically highly toxic to biological systems. Here, a versatile flame spray pyrolysis (FSP) synthetic process has been exploited to synthesize a library of iron doped (0–10 at wt%) TiO2 nanoparticles. These particles have been tested for photoactivation-mediated cytotoxicity using near-visible light exposure. The reduction in TiO2 band gap energy with incremental levels of Fe loading maintained the nanoparticle crystalline structure in spite of homogeneous Fe distribution (demonstrated by XRD, HRTEM, SAED, EFTEM, and EELS). Photochemical studies showed that band gap energy was reciprocally tuned proportional to the Fe content. The photo-oxidation capability of Fe-doped TiO2 was found to increase during near-visible light exposure. Use of a macrophage cell line to evaluate cytotoxic and ROS production showed increased oxidant injury and cell death in parallel with a decrease in band gap energy. These findings demonstrate the importance of band gap energy in the phototoxic response of the cell to TiO2 nanoparticles and reflect the potential of this material to generate adverse effects in humans and the environment during high intensity light exposure.
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影响因子：
17.1
作者：
George, Saji;Pokhrel, Suman;Xia, Tian;Gilbert, Benjamin;Ji, Zhaoxia;Schowalter, Marco;Rosenauer, Andreas;Damoiseaux, Robert;Bradley, Kenneth A.;Maedler, Lutz;Nel, Andre E.
通讯作者：
Nel, Andre E.
影响因子：
3.5
作者：
Reyes-Coronado, D.;Rodriguez-Gattorno, G.;Oskam, G.
通讯作者：
Oskam, G.
影响因子：
3.9
作者：
SERPONE, N;LAWLESS, D;HERRMANN, JM
通讯作者：
HERRMANN, JM
影响因子：
10.4
作者：
通讯作者：
--
影响因子：
3.3
作者：
Nagaveni, K;Hegde, MS;Madras, G
通讯作者：
Madras, G