Hierarchical growth of ZnFe2O4 for sensing applications
Hierarchical growth of ZnFe2O4 for sensing applications
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DOI：
10.1039/c5nj02547h
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发表时间：
2016-01-01
影响因子：
3.3
通讯作者：
Pal, Tarasankar
中科院分区：
文献类型：
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作者：
Sahoo, Ramkrishna;Santra, Sumita;Pal, Tarasankar
用改进的水热(MHT)技术制备了介孔锌铁氧体纳米花(NFs)。在溶液中加入尿素使FeCl3和ZnSO4水解，以均匀析出ZnFe2O4。在450℃热处理时，析出的产物得到介孔的ZnFe2O4Nf。一些重要的物理方法已经被用来表征固体状态下的纳米材料。所采用的反应策略证实了演化介孔材料的生长机理。在过氧化物酶模拟活性方面，锌铁氧化物核糖核酸得到了应用，这反过来又有助于选择性地用肉眼检测溶液中的过氧化氢和汞离子。而对H_2O_2和Hg2+的检测下限分别为0.1 mm和2.58×10~(-3)mm。为了研究过氧化物酶的活性，使用了无色的3，3‘，5，5’-四甲基联苯胺(TMB)，TMB在ZnFe2O4存在下被过氧化氢氧化成蓝色溶液，从而实现了对过氧化氢的传感。已经发现，Hg2+离子选择性地阻碍了蓝色的显色，从而使Hg2+传感成为可能。对Hg2+离子的合理选择再次表明了氮给体对Hg2+的强烈亲和力。这使得无需使用任何贵金属即可实现对Hg2+的传感。与TMB底物的氮供体之间强烈而明确的‘-N-Hg-N’结合作用导致蓝色漂白。在这里，我们首次报道了一种低于额定值的ZnFe2O4纳米花对Hg2+的光谱检测的有效性，并以一种经济有效的方式。另一方面，高介孔纳米花也被证明是丙酮的选择性传感器。基于上述反应/相互作用策略，所合成的非晶锌铁氧体有望成为生物应用和环境修复的高性价比传感器材料。
Mesoporous ZnFe2O4 nanoflowers (NFs) have been prepared using a modified hydrothermal (MHT) technique, developed in our laboratory. Urea has been brought in for hydrolysis of FeCl3 and ZnSO4 in solution to homogeneously precipitate ZnFe2O4. The precipitated product upon annealing at 450 degrees C results in mesoporous ZnFe2O4 NFs. Important physical methods have been used to characterize the NF material in the solid state. The growth mechanism of mesoporous NFs of evolution is confirmed by the adopted reaction strategy. The ZnFe2O4 NF finds application in peroxidase mimicking activity which in turn helps the selective naked eye detection of H2O2 and Hg2+ ions in solution. However, spectrophotometric detection limit goes down to 0.1 mM and 2.58 x 10(-3) mM for H2O2 and Hg2+, respectively. To contemplate peroxidase like activity, colorless 3,3',5,5'-tetramethylbenzidine (TMB) is employed which in turn oxidized to a blue solution by H2O2 in the presence of ZnFe2O4 rendering H2O2 sensing. It has been discovered that the blue color development is selectively held up by Hg2+ ion causing Hg2+ sensing possible. Judicious selection of Hg2+ ions once again indicates strong affinity of the nitrogen donor towards Hg2+. This makes Hg2+ sensing possible without the use of any noble metal. A strong and definite '-N-Hg-N' binding interaction with nitrogen donors of the TMB substrate causes blue color bleaching. Herein we report the usefulness of an under -rated ZnFe2O4 nanoflower for the first time to detect Hg2+ spectrophotometrically and in a cost-effective way. On the other hand, a highly mesoporous nanoflower has been shown to be a selective sensor for acetone also. Based on the above reaction/interaction strategies it is expected that the as -synthesized ZnFe2O4 NFs would stand as cost effective sensor materials for biological applications and environmental remediation.